Optimize PipeTable parsing: O(n²) → O(n) for 3.7x–85x speedup, enables 10K+ row tables (#922)

* Optimize PipeTable parsing: O(n²) → O(n) for large tables

Pipe tables were creating deeply nested tree structures where each pipe
delimiter contained all subsequent content as children, causing O(n²)
traversal complexity for n cells. This change restructures the parser to
use a flat sibling-based structure, treating tables as matrices rather
than nested trees.

Key changes:
- Set IsClosed=true on PipeTableDelimiterInline to prevent nesting
- Add PromoteNestedPipesToRootLevel() to flatten pipes nested in emphasis
- Update cell boundary detection to use sibling traversal
- Move EmphasisInlineParser before PipeTableParser in processing order
- Fix EmphasisInlineParser to continue past IsClosed delimiters
- Add ContainsParentOrSiblingOfType<T>() helper for flat structure detection

Performance improvements (measured on typical markdown content):

| Rows | Before    | After   | Speedup |
|------|-----------|---------|---------|
| 100  | 542 μs    | 150 μs  | 3.6x    |
| 500  | 23,018 μs | 763 μs  | 30x     |
| 1000 | 89,418 μs | 1,596 μs| 56x     |
| 1500 | 201,593 μs| 2,740 μs| 74x     |
| 5000 | CRASH     | 10,588 μs| ∞      |
| 10000| CRASH     | 18,551 μs| ∞      |

Tables with 5000+ rows previously crashed due to stack overflow from
recursive depth. They now parse successfully with linear time complexity.

* remove baseline results file

* Do not use System.Index and fix nullabillity checks for older platforms

.editorconfig

@@ -0,0 +1,43 @@
+# EditorConfig is awesome:http://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# All Files
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 4
+insert_final_newline = false
+trim_trailing_whitespace = true
+
+# Solution Files
+[*.slnx]
+indent_size = 2
+insert_final_newline = true
+
+# XML Project Files
+[*.{csproj,vbproj,vcxproj,vcxproj.filters,proj,projitems,shproj}]
+indent_size = 2
+
+# Configuration Files
+[*.{json,xml,yml,config,props,targets,nuspec,resx,ruleset}]
+indent_size = 2
+
+# Markdown Files
+[*.md]
+trim_trailing_whitespace = false
+
+# Web Files
+[*.{htm,html,js,ts,css,scss,less}]
+indent_size = 2
+insert_final_newline = true
+
+# Bash Files
+[*.sh]
+end_of_line = lf
+
+# C# files
+[*.cs]
+# License header
+file_header_template = Copyright (c) Alexandre Mutel. All rights reserved.\nThis file is licensed under the BSD-Clause 2 license.\nSee the license.txt file in the project root for more information.

.gitattributes

@@ -0,0 +1,3 @@
+* text=auto
+*.cs text=auto diff=csharp
+*.slnx text=auto eol=crlf

.github/FUNDING.yml

@@ -0,0 +1,12 @@
+# These are supported funding model platforms
+
+github: [xoofx]
+patreon: # Replace with a single Patreon username
+open_collective: # Replace with a single Open Collective username
+ko_fi: # Replace with a single Ko-fi username
+tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
+community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
+liberapay: # Replace with a single Liberapay username
+issuehunt: # Replace with a single IssueHunt username
+otechie: # Replace with a single Otechie username
+custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']

.github/workflows/ci.yml

@@ -0,0 +1,21 @@
+name: ci
+
+on:
+  push:
+    paths-ignore:
+    - 'doc/**'
+    - 'img/**'
+    - 'changelog.md'
+    - 'readme.md'
+  pull_request:
+
+jobs:
+  build:
+    uses: xoofx/.github/.github/workflows/dotnet.yml@main
+    with:
+      dotnet-version: |
+        6.0
+        8.0
+        9.0
+    secrets:
+      NUGET_TOKEN: ${{ secrets.NUGET_TOKEN }}    

.github/workflows/nuget_org_only.config

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+  </packageSources>
+</configuration>

.github/workflows/test-netstandard.yml

@@ -0,0 +1,44 @@
+name: Test netstandard
+
+on: pull_request
+
+jobs:
+  test-netstandard:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        netstandard-version: ['netstandard2.0', 'netstandard2.1']
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: |
+          8.0.x
+          9.0.x
+
+    - name: Patch build to test ${{ matrix.netstandard-version }}
+      run: |
+        cd src
+        sed -i 's/<TargetFrameworks>.*<\/TargetFrameworks>/<TargetFrameworks>${{ matrix.netstandard-version }}<\/TargetFrameworks>/' Markdig/Markdig.targets
+        sed -i 's/<TargetFrameworks>.*<\/TargetFrameworks>/<TargetFrameworks>net8.0;net9.0<\/TargetFrameworks>/' Markdig.Tests/Markdig.Tests.csproj
+        echo "Markdig.targets TFMs:"
+        grep "TargetFrameworks" Markdig/Markdig.targets
+        echo "Markdig.Tests.csproj TFMs:"
+        grep "TargetFrameworks" Markdig.Tests/Markdig.Tests.csproj
+
+    - name: Restore dependencies
+      run: dotnet restore src/Markdig.Tests/Markdig.Tests.csproj
+
+    - name: Test Debug
+      run: |
+        dotnet build src/Markdig.Tests/Markdig.Tests.csproj -c Debug --no-restore
+        dotnet test src/Markdig.Tests/Markdig.Tests.csproj -c Debug --no-build
+
+    - name: Test Release
+      run: |
+        dotnet build src/Markdig.Tests/Markdig.Tests.csproj -c Release --no-restore
+        dotnet test src/Markdig.Tests/Markdig.Tests.csproj -c Release --no-build

.gitignore

@@ -6,6 +6,10 @@
 *.user
 *.userosscache
 *.sln.docstates
+*.nuget.props
+*.nuget.targets
+src/.idea
+BenchmarkDotNet.Artifacts
 
 # User-specific files (MonoDevelop/Xamarin Studio)
 *.userprefs
@@ -136,7 +140,7 @@ publish/
 # Publish Web Output
 *.[Pp]ublish.xml
 *.azurePubxml
-# TODO: Comment the next line if you want to checkin your web deploy settings 
+# TODO: Comment the next line if you want to checkin your web deploy settings
 # but database connection strings (with potential passwords) will be unencrypted
 *.pubxml
 *.publishproj
@@ -214,3 +218,29 @@ FakesAssemblies/
 **/*.Server/GeneratedArtifacts
 **/*.Server/ModelManifest.xml
 _Pvt_Extensions
+
+# Common IntelliJ Platform excludes
+
+# User specific
+**/.idea/**/workspace.xml
+**/.idea/**/tasks.xml
+**/.idea/shelf/*
+**/.idea/dictionaries
+**/.idea/httpRequests/
+
+# Sensitive or high-churn files
+**/.idea/**/dataSources/
+**/.idea/**/dataSources.ids
+**/.idea/**/dataSources.xml
+**/.idea/**/dataSources.local.xml
+**/.idea/**/sqlDataSources.xml
+**/.idea/**/dynamic.xml
+
+# Rider
+# Rider auto-generates .iml files, and contentModel.xml
+**/.idea/**/*.iml
+**/.idea/**/contentModel.xml
+**/.idea/**/modules.xml
+
+# Remove artifacts produced by dotnet-releaser
+artifacts-dotnet-releaser/

.nuget/NuGet.Config

@@ -1,10 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<configuration>
-  <solution>
-    <add key="disableSourceControlIntegration" value="true" />
-  </solution>
-  <packageSources>
-    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
-    <add key="dotnet-core" value="http://myget.org/F/dotnet-core" />
-  </packageSources>
-</configuration>

.nuget/NuGet.targets

@@ -1,150 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-    <PropertyGroup>
-        <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">$(MSBuildProjectDirectory)\..\</SolutionDir>
-        
-        <!-- Enable the restore command to run before builds -->
-        <RestorePackages Condition="  '$(RestorePackages)' == '' ">false</RestorePackages>
-
-        <!-- Property that enables building a package from a project -->
-        <BuildPackage Condition=" '$(BuildPackage)' == '' ">false</BuildPackage>
-
-        <!-- Determines if package restore consent is required to restore packages -->
-        <RequireRestoreConsent Condition=" '$(RequireRestoreConsent)' != 'false' ">true</RequireRestoreConsent>
-        
-        <!-- Download NuGet.exe if it does not already exist -->
-        <DownloadNuGetExe Condition=" '$(DownloadNuGetExe)' == '' ">true</DownloadNuGetExe>
-    </PropertyGroup>
-    
-    <ItemGroup Condition=" '$(PackageSources)' == '' ">
-        <!-- Package sources used to restore packages. By default will used the registered sources under %APPDATA%\NuGet\NuGet.Config -->
-        <!--
-            <PackageSource Include="https://nuget.org/api/v2/" />
-            <PackageSource Include="https://my-nuget-source/nuget/" />
-        -->
-    </ItemGroup>
-
-    <PropertyGroup Condition=" '$(OS)' == 'Windows_NT'">
-        <!-- Windows specific commands -->
-        <NuGetToolsPath>$([System.IO.Path]::Combine($(SolutionDir), ".nuget"))</NuGetToolsPath>
-        <PackagesConfig>$([System.IO.Path]::Combine($(ProjectDir), "packages.config"))</PackagesConfig>
-    </PropertyGroup>
-    
-    <PropertyGroup Condition=" '$(OS)' != 'Windows_NT'">
-        <!-- We need to launch nuget.exe with the mono command if we're not on windows -->
-        <NuGetToolsPath>$(SolutionDir).nuget</NuGetToolsPath>
-        <PackagesConfig>packages.config</PackagesConfig>
-    </PropertyGroup>
-    
-    <PropertyGroup>
-        <!-- NuGet command -->
-        <NuGetExePath Condition=" '$(NuGetExePath)' == '' ">$(NuGetToolsPath)\nuget.exe</NuGetExePath>
-        <PackageSources Condition=" $(PackageSources) == '' ">@(PackageSource)</PackageSources>
-        
-        <NuGetCommand Condition=" '$(OS)' == 'Windows_NT'">"$(NuGetExePath)"</NuGetCommand>
-        <NuGetCommand Condition=" '$(OS)' != 'Windows_NT' ">mono --runtime=v4.0.30319 $(NuGetExePath)</NuGetCommand>
-
-        <PackageOutputDir Condition="$(PackageOutputDir) == ''">$(TargetDir.Trim('\\'))</PackageOutputDir>
-        
-        <RequireConsentSwitch Condition=" $(RequireRestoreConsent) == 'true' ">-RequireConsent</RequireConsentSwitch>
-        <!-- Commands -->
-        <RestoreCommand>$(NuGetCommand) install "$(PackagesConfig)" -source "$(PackageSources)"  $(RequireConsentSwitch) -solutionDir "$(SolutionDir) "</RestoreCommand>
-        <BuildCommand>$(NuGetCommand) pack "$(ProjectPath)" -p Configuration=$(Configuration) -o "$(PackageOutputDir)" -symbols</BuildCommand>
-
-        <!-- We need to ensure packages are restored prior to assembly resolve -->
-        <ResolveReferencesDependsOn Condition="$(RestorePackages) == 'true'">
-            RestorePackages;
-            $(ResolveReferencesDependsOn);
-        </ResolveReferencesDependsOn>
-
-        <!-- Make the build depend on restore packages -->
-        <BuildDependsOn Condition="$(BuildPackage) == 'true'">
-            $(BuildDependsOn);
-            BuildPackage;
-        </BuildDependsOn>
-    </PropertyGroup>
-
-    <Target Name="CheckPrerequisites">
-        <!-- Raise an error if we're unable to locate nuget.exe  -->
-        <Error Condition="'$(DownloadNuGetExe)' != 'true' AND !Exists('$(NuGetExePath)')" Text="Unable to locate '$(NuGetExePath)'" />
-        <SetEnvironmentVariable EnvKey="VisualStudioVersion" EnvValue="$(VisualStudioVersion)" Condition=" '$(VisualStudioVersion)' != '' AND '$(OS)' == 'Windows_NT' " />
-        <!--
-        Take advantage of MsBuild's build dependency tracking to make sure that we only ever download nuget.exe once.
-        This effectively acts as a lock that makes sure that the download operation will only happen once and all
-        parallel builds will have to wait for it to complete.
-        -->
-        <MsBuild Targets="_DownloadNuGet" Projects="$(MSBuildThisFileFullPath)" Properties="Configuration=NOT_IMPORTANT" />
-    </Target>
-
-    <Target Name="_DownloadNuGet">
-        <DownloadNuGet OutputFilename="$(NuGetExePath)" Condition=" '$(DownloadNuGetExe)' == 'true' AND !Exists('$(NuGetExePath)')" />
-    </Target>
-
-    <Target Name="RestorePackages" DependsOnTargets="CheckPrerequisites">
-        <Exec Command="$(RestoreCommand)"
-              Condition="'$(OS)' != 'Windows_NT' And Exists('$(PackagesConfig)')" />
-              
-        <Exec Command="$(RestoreCommand)"
-              LogStandardErrorAsError="true"
-              Condition="'$(OS)' == 'Windows_NT' And Exists('$(PackagesConfig)')" />
-    </Target>
-
-    <Target Name="BuildPackage" DependsOnTargets="CheckPrerequisites">
-        <Exec Command="$(BuildCommand)" 
-              Condition=" '$(OS)' != 'Windows_NT' " />
-              
-        <Exec Command="$(BuildCommand)"
-              LogStandardErrorAsError="true"
-              Condition=" '$(OS)' == 'Windows_NT' " />
-    </Target>
-    
-    <UsingTask TaskName="DownloadNuGet" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
-        <ParameterGroup>
-            <OutputFilename ParameterType="System.String" Required="true" />
-        </ParameterGroup>
-        <Task>
-            <Reference Include="System.Core" />
-            <Using Namespace="System" />
-            <Using Namespace="System.IO" />
-            <Using Namespace="System.Net" />
-            <Using Namespace="Microsoft.Build.Framework" />
-            <Using Namespace="Microsoft.Build.Utilities" />
-            <Code Type="Fragment" Language="cs">
-                <![CDATA[
-                try {
-                    OutputFilename = Path.GetFullPath(OutputFilename);
-
-                    Log.LogMessage("Downloading latest version of NuGet.exe...");
-                    WebClient webClient = new WebClient();
-                    webClient.DownloadFile("https://nuget.org/nuget.exe", OutputFilename);
-
-                    return true;
-                }
-                catch (Exception ex) {
-                    Log.LogErrorFromException(ex);
-                    return false;
-                }
-            ]]>
-            </Code>
-        </Task>
-    </UsingTask>
-    
-     <UsingTask TaskName="SetEnvironmentVariable" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
-        <ParameterGroup>
-            <EnvKey ParameterType="System.String" Required="true" />
-            <EnvValue ParameterType="System.String" Required="true" />
-        </ParameterGroup>
-        <Task>
-            <Using Namespace="System" />
-            <Code Type="Fragment" Language="cs">
-                <![CDATA[
-                try {
-                    Environment.SetEnvironmentVariable(EnvKey, EnvValue, System.EnvironmentVariableTarget.Process);
-                }
-                catch  {
-                }
-            ]]>
-            </Code>
-        </Task>
-    </UsingTask>
-</Project>

changelog.md

@@ -0,0 +1,259 @@
+# Changelog
+
+## 0.27.0 (23 Jan 2022)
+- Fix link reference definition parse bug with title and CRLF ([PR #590](https://github.com/lunet-io/markdig/pull/590))
+- Move tests to net6.0 ([PR #560](https://github.com/lunet-io/markdig/pull/560))
+
+## 0.26.0 (27 Aug 2021)
+- Fix rendering diff between line endings ([PR #560](https://github.com/lunet-io/markdig/pull/560))
+- Make Mathematics extension respect EnableHtml* options ([PR #570](https://github.com/lunet-io/markdig/pull/570))
+
+## 0.25.0 (10 June 2021)
+- Fix regression when parsing link reference definitions (#543)
+- Make digits in JiraKey's posible ([PR #548](https://github.com/lunet-io/markdig/pull/548))
+
+## 0.24.0 (20 Mar 2021)
+- Add support for roundtrip Markdown ([PR #481](https://github.com/lunet-io/markdig/pull/481))
+- Introduction of nullability ([PR #522](https://github.com/lunet-io/markdig/pull/522) [PR #524](https://github.com/lunet-io/markdig/pull/524) [PR #525](https://github.com/lunet-io/markdig/pull/525) [PR #526](https://github.com/lunet-io/markdig/pull/526) [PR #527](https://github.com/lunet-io/markdig/pull/527))
+- Various internal cleanup and small performance improvements ([PR #521](https://github.com/lunet-io/markdig/pull/521) [PR #524](https://github.com/lunet-io/markdig/pull/524) [PR #525](https://github.com/lunet-io/markdig/pull/525) [PR #529](https://github.com/lunet-io/markdig/pull/529) [PR #531](https://github.com/lunet-io/markdig/pull/531) [PR #532](https://github.com/lunet-io/markdig/pull/532))
+
+## 0.23.0 (16 Jan 2021)
+- Add depth limits to avoid pathological-case parsing times/StackOverflows (#500)
+- Breaking change: rename AutolineInlineParser to AutolinkInlineParser
+
+## 0.22.1 (2 Dec 2020)
+- Update logo for NuGet package
+
+## 0.22.0 (05 Oct 2020)
+- Fix Setext headings in block quotes.
+- Fix tel: treated as autolink ([PR #478](https://github.com/lunet-io/markdig/pull/478))
+- Make Inline.FirstParentOfType public ([PR #474](https://github.com/lunet-io/markdig/pull/474))
+- Fix `&` to be parsed as a punctuation while it was detected as a html entity in certain cases ([PR #471](https://github.com/lunet-io/markdig/pull/471))
+- Add ParentBlock property to ContainerInline ([PR #468](https://github.com/lunet-io/markdig/pull/468))
+
+## 0.21.1 (17 Aug 2020)
+- Fix Markdig.Signed on GitHub Actions
+
+## 0.21.0 (17 Aug 2020)
+- Restore support for .NET 4.5 (#)
+- Add IReadonlyList interface to ContainerBlock to unify and simplify enumeration (#425)
+- Fix relative uri detection to be cross-platform compatible (#430)
+- Escape URLs scheme (#431)
+- Fix media links (#435)
+- Fix parsing math blocks with no leading or trailing whitespace (#452)
+- Add support for autolink `tel:` uri (#453)
+- Fallback to non-punycode encoding for invalid IDN urls (#449)
+- Pipe Tables: Normalize using header column count (#455)
+- Expose IndentCount of FencedCodeBlock (#464)
+
+## 0.20.0 (18 Apr 2020)
+- Markdig is now compatible only with `NETStandard 2.0`, `NETStandard 2.1`, `NETCoreApp 2.1` and `NETCoreApp 3.1`.
+- Many performance improvements from [PR #416](https://github.com/lunet-io/markdig/pull/416) 
+[PR #417](https://github.com/lunet-io/markdig/pull/417)
+[PR #418](https://github.com/lunet-io/markdig/pull/418) 
+[PR #421](https://github.com/lunet-io/markdig/pull/421) 
+[PR #422](https://github.com/lunet-io/markdig/pull/422) 
+[PR #410](https://github.com/lunet-io/markdig/pull/410)
+
+## 0.18.3 (8 Mar 2020)
+- Publish NuGet Symbol packages
+
+## 0.18.2 (8 Mar 2020)
+- Optimize LineReader.ReadLine in [PR #393](https://github.com/lunet-io/markdig/pull/393)
+- Use HashSet<T> instead of Dictionary<TKey, TValue> in CharacterMap<T> in [PR #394](https://github.com/lunet-io/markdig/pull/394)
+- Use BitVector128 in CharacterMap<T> in [PR #396](https://github.com/lunet-io/markdig/pull/396)
+- Optimizations in StringLineGroup in [PR #399](https://github.com/lunet-io/markdig/pull/399)
+- Fixed a bug in HeadingRenderer in [PR #402](https://github.com/lunet-io/markdig/pull/402)
+- Fixes issue #303 in [PR #404](https://github.com/lunet-io/markdig/pull/404)
+- Make output of HtmlTableRenderer XML wellformed in [PR #406](https://github.com/lunet-io/markdig/pull/406)
+
+## 0.18.1 (21 Jan 2020)
+- Re-allow emojis and smileys customization, that was broken in [PR #308](https://github.com/lunet-io/markdig/pull/308) ([PR #386](https://github.com/lunet-io/markdig/pull/386))
+- Add `IHostProvider` for medialink customization (#337), support protocol-less url (#135) ([(PR #341)](https://github.com/lunet-io/markdig/pull/341))
+- Add missing Descendants<T> overload ([(PR #387)](https://github.com/lunet-io/markdig/pull/387))
+
+## 0.18.0 (24 Oct 2019)
+- Ignore backslashes in GFM AutoLinks ([(PR #357)](https://github.com/lunet-io/markdig/pull/357))
+- Fix SmartyPants quote matching ([(PR #360)](https://github.com/lunet-io/markdig/pull/360))
+- Fix generic attributes with values of length 1 ([(PR #361)](https://github.com/lunet-io/markdig/pull/361))
+- Fix link text balanced bracket matching ([(PR #375)](https://github.com/lunet-io/markdig/pull/375))
+- Improve overall performance and substantially reduce allocations ([(PR #377)](https://github.com/lunet-io/markdig/pull/377))
+
+## 0.17.1 (04 July 2019)
+- Fix regression when escaping HTML characters ([(PR #340)](https://github.com/lunet-io/markdig/pull/340))
+- Update Emoji Dictionary ([(PR #346)](https://github.com/lunet-io/markdig/pull/346))
+
+## 0.17.0 (10 May 2019)
+- Update to latest CommonMark specs 0.29 ([(PR #327)](https://github.com/lunet-io/markdig/pull/327))
+- Add `AutoLinkOptions` with `OpenInNewWindow`, `UseHttpsForWWWLinks` ([(PR #327)](https://github.com/lunet-io/markdig/pull/327))
+- Add `DisableHeadings` extension method to `MarkdownPipelineBuilder` ([(PR #327)](https://github.com/lunet-io/markdig/pull/327))
+- Drop support for netstandard1.1 and Portable Class Libraries ([(PR #319)](https://github.com/lunet-io/markdig/pull/319))
+- Allow non-ASCII characters in url domain names ([(PR #319)](https://github.com/lunet-io/markdig/pull/319))
+- Add better support for youtu.be link ([(PR #336)](https://github.com/lunet-io/markdig/pull/336))
+- Fix backsticks in Markdown.Normalize ([(PR #334)](https://github.com/lunet-io/markdig/pull/334))
+
+## 0.16.0 (25 Feb 2019)
+- Improve performance of emoji-abbreviation parser ([(PR #305)](https://github.com/lunet-io/markdig/pull/305))
+- Change output for math extension to use a rendering more compatible with existing Math JS libraries ([(PR #311)](https://github.com/lunet-io/markdig/pull/311))
+- Improve emphasis parser to allow to match more than 2 characters ([(PR #301)](https://github.com/lunet-io/markdig/pull/301))
+- Output attached attributes to a `<tr>` from a table row ([(PR #300)](https://github.com/lunet-io/markdig/pull/300))
+- Improve MarkdownObject.Descendants() search ([(PR #288)](https://github.com/lunet-io/markdig/pull/288))
+- Allow to pass a `MarkdownParserContext` ([(PR #285)](https://github.com/lunet-io/markdig/pull/285))
+
+## 0.15.7 (11 Jan 2019)
+- Add configurable leading count for ATX headers ([(PR #282)](https://github.com/lunet-io/markdig/pull/282))
+- Render XML well-formed boolean attribute ([(PR #281)](https://github.com/lunet-io/markdig/pull/281))
+
+## 0.15.6 (28 Dec 2018)
+- Fix potential hang when parsing LinkReferenceDefinition #278
+- Fix parsing of an invalid html entity (#277)
+- Fix IndexOutOfRangeException while parsing fenced code block with a single trailing space (#276)
+- Add tests for checking that ArgumentOutOfRangeException doesn't occur on invalid input md string (#275)
+
+## 0.15.5 (11 Dec 2018)
+- Empty image alt text for link reference definitions ([(PR #254)](https://github.com/lunet-io/markdig/pull/254))
+- Fix AutoLink Match links without slash after domain ([(PR #260)](https://github.com/lunet-io/markdig/pull/260))
+- Make AutoLink ValidPreviousCharacters configurable ([(PR #264)](https://github.com/lunet-io/markdig/pull/264))
+- Ensuring line breaks when renderer does not have html enabled ([(PR #270)](https://github.com/lunet-io/markdig/pull/270))
+
+## 0.15.4 (07 Oct 2018)
+- Add autolink domain GFM validation ([(PR #253)](https://github.com/lunet-io/markdig/pull/253))
+
+## 0.15.3 (15 Sep 2018)
+- Add support for RTL ([(PR #239)](https://github.com/lunet-io/markdig/pull/239))
+- Add MarkdownDocument.LineCount ([(PR #241)](https://github.com/lunet-io/markdig/pull/241))
+- Fix source positions for link definitions ([(PR #243)](https://github.com/lunet-io/markdig/pull/243))
+- Add ListItemBlock.Order ([(PR #244)](https://github.com/lunet-io/markdig/pull/244))
+- Add MarkdownDocument.LineStartIndexes ([(PR #247)](https://github.com/lunet-io/markdig/pull/247))
+
+## 0.15.2 (21 Aug 2018)
+- Fix footnotes parsing when they are defined after a container that has been closed in the meantime (#223)
+
+## 0.15.1 (10 July 2018)
+- Add support for `netstandard2.0`
+- Make AutoIdentifierExtension thread safe
+
+## 0.15.0 (4 Apr 2018)
+- Add `ConfigureNewLine` extension method to `MarkdownPipelineBuilder` ([(PR #214)](https://github.com/lunet-io/markdig/pull/214))
+- Add alternative `Use` extension method to `MarkdownPipelineBuilder` that receives an object instance ([(PR #213)](https://github.com/lunet-io/markdig/pull/213))
+- Added class attribute to media link extension ([(PR #203)](https://github.com/lunet-io/markdig/pull/203))
+- Optional link rewriter func for HtmlRenderer #143 ([(PR #201)](https://github.com/lunet-io/markdig/pull/201))
+- Upgrade NUnit3TestAdapter from 3.2 to 3.9 to address Resharper test runner problems ([(PR #199)](https://github.com/lunet-io/markdig/pull/199))
+- HTML renderer supports converting relative URLs on links and images to absolute #143 ([(PR #197)](https://github.com/lunet-io/markdig/pull/197))
+
+## 0.14.9 (15 Jan 2018)
+- AutoLinkParser should to remove mailto: in outputted text ([(PR #195)](https://github.com/lunet-io/markdig/pull/195))
+- Add support for `music.yandex.ru` and `ok.ru` for MediaLinks extension ([(PR #193)](https://github.com/lunet-io/markdig/pull/193))
+## 0.14.8 (05 Dec 2017)
+- Fix potential StackOverflow exception when processing deep nested `|` delimiters (#179)
+## 0.14.7 (25 Nov 2017)
+- Fix autolink attached attributes not being displayed properly (#175)
+## 0.14.6 (21 Nov 2017)
+- Fix yaml frontmatter issue when ending with a empty line (#170)
+## 0.14.5 (18 Nov 2017)
+- Fix changelog link from nuget package
+## 0.14.4 (18 Nov 2017)
+- Add changelog.md
+- Fix bug when a thematic break is inside a fenced code block inside a pending list (#164)
+- Add support for GFM autolinks (#165, #169)
+- Better handle YAML frontmatter in case the opening `---` is never actually closed (#160)
+- Fix link conflict between a link to an image definition and heading auto-identifiers (#159)
+## 0.14.3
+- Make EmojiExtension.EnableSmiley public
+## 0.14.2
+- Fix issue with emphasis preceded/followed by an HTML entity (#157)
+- Add support for link reference definitions for Normalize renderer (#155)   
+- Add option to disable smiley parsing in EmojiAndSmiley extension
+## 0.14.1
+- Fix crash in Markdown.Normalize to handle HtmlBlock correctly        
+- Add better handling of bullet character for lists in Markdown.Normalize
+## 0.14.0
+- Add Markdown.ToPlainText, Add option HtmlRenderer.EnableHtmlForBlock.
+- Add Markdown.Normalize, to allow to normalize a markdown document. Add NormalizeRenderer, to render a MarkdownDocument back to markdown.
+## 0.13.4
+- Add support for single table header row without a table body rows (#141)
+- ADd support for `nomnoml` diagrams
+## 0.13.3
+- Add support for Pandoc YAML frontmatter (#138)
+## 0.13.2
+- Add support for UAP10.0 (#137)
+## 0.13.1
+- Fix indenting issue after a double digit list block using a tab (#134)
+## 0.13.0
+- Update to latest CommonMark specs 0.28
+## 0.12.3
+ - Fix issue with HTML blocks for heading h2,h3,h4,h5,h6 that were not correctly identified as HTML blocks as per CommonMark spec
+## 0.12.2
+ - Fix issue with generic attributes used just before a pipe table (issue #121)
+## 0.12.1
+ - Fix issue with media links extension when a URL to video is used, an unexpected closing `&lt;/iframe&gt;` was inserted (issue #119)
+## 0.12.0
+ - Add new extension JiraLink support (thanks to @clarkd)
+ - Fix issue in html attributes not parsing correctly properties (thanks to @meziantou)
+ - Fix issues detected by an automatic static code analysis tool
+## 0.11.0
+ - Fix issue with math extension and $$ block parsing not handling correctly beginning of a $$ as a inline math instead (issue #107)
+ - Fix issue with custom attributes for emphasis
+ - Add support for new special custom arrows emoji (`->` `<-` `<->` `<=` `=>` `<==>`)
+## 0.10.7
+ - Fix issue when an url ends by a dot `.`
+## 0.10.6
+ - Fix emphasis with HTML entities
+## 0.10.5
+ - Several minor fixes
+## 0.10.4
+ - Fix issue with autolinks
+ - Normalize number of columns for tables
+## 0.10.3
+ - Fix issue with pipetables shifting a cell to a new column (issue #73)
+## 0.10.2
+ - Fix exception when trying to urlize an url with an unicode character outside the supported range by NormD (issue #75)
+## 0.10.1
+- Update to latest CommonMark specs
+- Fix source span for LinkReferenceDefinition
+## 0.10.0
+- Breaking change of the IMarkdownExtension to allow to receive the MarkdownPipeline for the renderers setup
+## 0.9.1
+- Fix regression bug with conflicts between autolink extension and html inline/regular links
+## 0.9.0
+- Add new Autolink extension
+## 0.8.5
+- Allow to force table column alignment to left
+## 0.8.4
+- Fix issue when calculating the span of an indented code block within a list. Make sure to include first whitespace on the line
+## 0.8.3
+- fix NullReferenceException with Gridtables extension when a single `+` is entered on a line
+## 0.8.2
+- fix potential cast exception with Abbreviation extension and empty literals
+## 0.8.1
+- new extension to disable URI escaping for non-US-ASCII characters to workaround a bug in Edge/IE
+- Fix an issue with abbreviations with left/right multiple non-punctuation/space characters
+## 0.8.0
+- Update to latest CommonMark specs
+- Fix empty literal
+- Add YAML frontmatter extension
+## 0.7.5
+- several bug fixes (pipe tables, disable HTML, special attributes, inline maths, abbreviations...)
+- add support for rowspan in grid tables
+## 0.7.4
+- Fix bug with strong emphasis starting at the beginning of a line
+## 0.7.3
+- Fix threading issue with pipeline
+## 0.7.2
+- Fix rendering of table colspan with non english locale
+- Fix grid table colspan parsing
+- Add nofollow extension for links
+## 0.7.1
+- Fix issue in smarty pants which could lead to an InvalidCastException
+- Update parsers to latest CommonMark specs
+## 0.7.0
+- Update to latest NETStandard.Library 1.6.0
+- Fix issue with digits in auto-identifier extension
+- Fix incorrect start of span calculated for code indented blocks
+## 0.6.2
+- Handle latest CommonMark specs for corner cases for emphasis (See https://talk.commonmark.org/t/emphasis-strong-emphasis-corner-cases/2123/1 )
+## 0.6.1:
+- Fix issue with autoidentifier extension overriding manual HTML attributes id on headings
+## 0.6.0
+- Fix conflicts between PipeTables and SmartyPants extensions
+- Add SelfPipeline extension

contributing.md

@@ -0,0 +1,36 @@
+# How to Contribute
+
+Thanks for your interest in contributing to `Markdig`! Here are a few general guidelines on contributing and
+reporting bugs that we ask you to review. Following these guidelines helps to communicate that you respect the time of
+the contributors managing and developing this open source project.
+
+## Reporting Issues
+
+Before reporting a new issue, please ensure that the issue was not already reported or fixed by searching through our
+[issues list](https://github.com/xoofx/markdig/issues).
+
+When creating a new issue, please be sure to include a **title and clear description**, as much relevant information as
+possible, and, if possible, a test case.
+
+## Sending Pull Requests
+
+Before sending a new pull request, take a look at existing pull requests and issues to see if the proposed change or fix
+has been discussed in the past, or if the change was already implemented but not yet released.
+
+We expect new pull requests to include tests for any affected behavior, and, as we follow semantic versioning, we may
+reserve breaking changes until the next major version release.
+
+## Other Ways to Contribute
+
+We welcome anyone that wants to contribute to `Markdig` to triage and reply to open issues to help troubleshoot
+and fix existing bugs. Here is what you can do:
+
+- Help ensure that existing issues follows the recommendations from the _[Reporting Issues](#reporting-issues)_ section,
+  providing feedback to the issue's author on what might be missing.
+  instructions and code samples.
+- Review existing pull requests, and testing patches against real existing applications that use `Markdig`.
+- Write a test, or add a missing test case to an existing test.
+
+Thanks again for your interest on contributing to `Markdig`!
+
+:heart:

doc/parsing-ast.md

@@ -0,0 +1,134 @@
+# The Abstract Syntax Tree
+
+If successful, the `Markdown.Parse(...)` method returns the abstract syntax tree (AST) of the source text.
+
+This will be an object of the `MarkdownDocument` type, which is in turn derived from a more general block container and is part of a larger taxonomy of classes which represent different semantic constructs of a markdown syntax tree.
+
+This document will discuss the different types of elements within the Markdig representation of the AST.
+
+## Structure of the AST
+
+Within Markdig, there are two general types of node in the markdown syntax tree: `Block`, and `Inline`.  Block nodes may contain inline nodes, but the reverse is not true.  Blocks may contain other blocks, and inlines may contain other inlines.
+
+The root of the AST is the `MarkdownDocument` which is itself derived from a container block but also contains information on the line count and starting positions within the document.  Nodes in the AST have links both to parent and children, allowing the edges in the tree to be traversed efficiently in either direction.
+
+Different semantic constructs are represented by types derived from the `Block` and `Inline` types, which are both `abstract` themselves.  These elements are produced by `BlockParser` and `InlineParser` derived types, respectively, and so new constructs can be added with the implementation of a new block or inline parser and a new block or inline type, as well as an extension to register it in the pipeline. For more information on extending Markdig this way refer to the [Extensions/Parsers](parsing-extensions.md) document.
+
+The AST is assembled by the static method `Markdown.Parse(...)` using the collections of block and inline parsers contained in the `MarkdownPipeline`.  For more detailed information refer to the [Markdig Parsing Overview](parsing-overview.md) document.
+
+### Quick Examples: Descendants API
+
+The easiest way to traverse the abstract syntax tree is with a group of extension methods that have the name `Descendants`.  Several different overloads exist to allow it to search for both `Block` and `Inline` elements, starting from any node in the tree.
+
+The `Descendants` methods return `IEnumerable<MarkdownObject>` or `IEnumerable<T>` as their results.  Internally they are using `yield return` to perform edge traversals lazily.
+
+#### Depth-First Like Traversal of All Elements
+
+```csharp
+MarkdownDocument result = Markdown.Parse(sourceText, pipeline);
+
+// Iterate through all MarkdownObjects in a depth-first order
+foreach (var item in result.Descendants())
+{
+    Console.WriteLine(item.GetType());
+
+    // You can use pattern matching to isolate elements of certain type,
+    // otherwise you can use the filtering mechanism demonstrated in the
+    // next section
+    if (item is ListItemBlock listItem) 
+    {
+        // ...
+    }
+}
+```
+
+#### Filtering of Specific Child Types
+
+Filtering can be performed using the `Descendants<T>()` method, in which T is required to be derived from `MarkdownObject`.
+
+```csharp
+MarkdownDocument result = Markdown.Parse(sourceText, pipeline);
+
+// Iterate through all ListItem blocks
+foreach (var item in result.Descendants<ListItemBlock>())
+{
+    // ...
+}
+
+// Iterate through all image links
+foreach (var item in result.Descendants<LinkInline>().Where(x => x.IsImage)) 
+{
+    // ...
+}
+```
+
+#### Combined Hierarchies
+
+The `Descendants` method can be used on any `MarkdownObject`, not just the root node, so complex hierarchies can be queried.
+
+```csharp
+MarkdownDocument result = Markdown.Parse(sourceText, pipeline);
+
+// Find all Emphasis inlines which descend from a ListItem block
+var items = document.Descendants<ListItemBlock>()
+    .Select(block => block.Descendants<EmphasisInline>());
+
+// Find all Emphasis inlines whose direct parent block is a ListItem
+var other = document.Descendants<EmphasisInline>()
+    .Where(inline => inline.ParentBlock is ListItemBlock);
+```
+
+## Block Elements
+
+Block elements all derive from `Block` and may be one of two types:
+
+1. `ContainerBlock`, which is a block which holds other blocks (`MarkdownDocument` is itself derived from this)
+2. `LeafBlock`, which is a block that has no child blocks, but may contain inlines
+
+Block elements in markdown refer to things like paragraphs, headings, lists, code, etc.  Most blocks may contain inlines, with the exception of things like code blocks.
+
+### Properties of Blocks
+
+The following are properties of `Block` objects which warrant elaboration. For a full list of properties see the generated API documentation (coming soon).
+
+#### Block Parent
+All blocks have a reference to a parent (`Parent`) of type `ContainerBlock?`, which allows for efficient traversal up the abstract syntax tree. The parent will be `null` in the case of the root node (the `MarkdownDocument`). 
+
+#### Parser
+
+All blocks have a reference to a parser (`Parser`) of type `BlockParser?` which refers to the instance of the parser which created this block. 
+
+#### IsOpen Flag
+
+Blocks have an `IsOpen` boolean flag which is set true while they're being parsed and then closed when parsing is complete.  
+
+Blocks are created by `BlockParser` objects which are managed by an instance of a `BlockProcessor` object. During the parsing algorithm the `BlockProcessor` maintains a list of all currently open `Block` objects as it steps through the source line by line. The `IsOpen` flag indicates to the `BlockProcessor` that the block should remain open as the next line begins.  If the `IsOpen` flag is not directly set by the `BlockParser` on each line, the `BlockProcessor` will consider the `Block` fully parsed and will no longer call its `BlockParser` on it.
+
+#### IsBreakable Flag
+
+Blocks are either breakable or not, specified by the `IsBreakable` flag.  If a block is non-breakable it indicates to the parser that the close condition of any parent container do not apply so long as the non-breakable child block is still open.
+
+The only built-in example of this is the `FencedCodeBlock`, which, if existing as the child of a container block of some sort, will prevent that container from being closed before the `FencedCodeBlock` is closed, since any characters inside the `FencedCodeBlock` are considered to be valid code and not the container's close condition.
+
+#### RemoveAfterProcessInlines
+
+
+
+## Inline Elements
+
+Inlines in markdown refer to things like embellishments (italics, bold, underline, etc), links, urls, inline code, images, etc.
+
+Inline elements may be one of two types:
+
+1. `Inline`, whose parent is always a `ContainerInline` 
+2. `ContainerInline`, derived from `Inline`, which contains other inlines.  `ContainerInline` also has a `ParentBlock` property of type `LeafBlock?`
+
+
+**(Is there anything special worth documenting about inlines or types of inlines?)**
+
+## The SourceSpan Struct
+
+If the pipeline was configured with `.UsePreciseSourceLocation()`, all elements in the abstract syntax tree will contain a reference to the location in the original source where they occurred.  This is done with the `SourceSpan` type, a custom Markdig `struct` which provides a start and end location.
+
+All objects derived from `MarkdownObject` contain the `Span` property, which is of type `SourceSpan`.  
+

doc/parsing-extensions.md

@@ -0,0 +1,127 @@
+# Extensions and Parsers
+
+Markdig was [implemented in such a way](http://xoofx.github.io/blog/2016/06/13/implementing-a-markdown-processor-for-dotnet/) as to be extremely pluggable, with even basic behaviors being mutable and extendable.
+
+The basic mechanism for extension of Markdig is the `IMarkdownExtension` interface, which allows any implementing class to be registered with the pipeline builder and thus to directly modify the collections of `BlockParser` and `InlineParser` objects which end up in the pipeline.
+
+This document discusses the `IMarkdownExtension` interface, the `BlockParser` abstract base class, and the `InlineParser` abstract base class, which together are the foundation of extending Markdig's parsing machinery.
+
+## Creating Extensions
+
+Extensions can vary from very simple to very complicated. 
+
+A simple extension, for example, might simply find a parser already in the pipeline and modify a setting on it.  An example of this is the `SoftlineBreakAsHardlineExtension`, which locates the `LineBreakInlineParser` and modifies a single boolean flag on it.
+
+A complex extension, on the other hand, might add an entire taxonomy of new `Block` and `Inline` types, as well as several related parsers and renderers, and require being added to the the pipeline in a specific order in relation to other extensions which are already configured. The `FootnoteExtension` and `PipeTableExtension` are examples of more complex extensions.
+
+For extensions that don't require order considerations, the implementation of the extension itself is adequate, and the extension can be added to the pipeline with the generic `Use<TExtension>()` method on the pipeline builder. For extensions which do require order considerations, it is best to create an extension method on the `MarkdownPipelineBuilder` to perform the registration.  See the following two sections for further information.
+
+### Implementation of an Extension
+
+The [IMarkdownExtension.cs](https://github.com/xoofx/markdig/blob/master/src/Markdig/IMarkdownExtension.cs) interface specifies two methods which must be implemented.
+
+The first, which takes only the pipeline builder as an argument, is called when the `Build()` method on the pipeline builder is invoked, and should set up any modifications to the parsers or parser collections. These parsers will then be used by the main parsing algorithm to process the source text.
+
+```csharp
+void Setup(MarkdownPipelineBuilder pipeline);
+```
+
+The second, which takes the pipeline itself and a renderer, is used to set up a rendering component in order to convert any special `MarkdownObject` types associated with the extension into an output.  This is not relevant for parsing, but is necessary for rendering.
+
+```csharp
+void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer);
+```
+
+The extension can then be registered to the pipeline builder using the `Use<TExtension>()` method.  A skeleton example is given below:
+
+```csharp
+public class MySpecialBlockParser : BlockParser 
+{
+    // ...
+}
+
+public class MyExtension : IMarkdownExtension 
+{
+    void Setup(MarkdownPipelineBuilder pipeline)
+    {
+        pipeline.BlockParsers.AddIfNotAlready<MySpecialBlockParser>();
+    }
+
+    void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer) { }
+}
+```
+
+```csharp
+var builder = new MarkdownPipelineBuilder()
+    .Use<MyExtension>();
+```
+
+### Pipeline Builder Extension Methods
+
+For extensions which require specific ordering and/or need to perform multiple operations to register with the builder, it's recommended to create an extension method.
+
+```csharp
+public static class MyExtensionMethods 
+{
+    public static MarkdownPipelineBuilder UseMyExtension(this MarkdownPipelineBuilder pipeline)
+    {
+        // Directly access or modify pipeline.Extensions here, with the ability to
+        // search for other extensions, insert before or after, remove other extensions,
+        // or modify their settings.
+
+        // ...
+
+        return pipeline;
+    }
+}
+
+```
+
+### Simple Extension Example
+
+An example of a simple extension which does not add any new parsers, but instead creates a new, horrific emphasis tag, marked by triple percentage signs.  This example is based on [CitationExtension.cs](https://github.com/xoofx/markdig/blob/master/src/Markdig/Extensions/Citations/CitationExtension.cs)
+
+```csharp
+/// <summary> 
+/// An extension which applies to text of the form %%%text%%%
+/// </summary>
+public class BlinkExtension : IMarkdownExtension
+{
+    // This setup method will be run when the pipeline builder's `Build()` method is invoked. As this
+    // is a simple, self-contained extension we won't be adding anything new, but rather finding an 
+    // existing parser already in the pipeline and adding some settings to it.
+    public void Setup(MarkdownPipelineBuilder pipeline)
+    {
+        // We check the pipeline builder's inline parser collection and see if we can find a parser
+        // registered of the type EmphasisInlineParser. This is the parser which nominally handles
+        // bold and italic emphasis, but we know from its documentation that it is a general parser
+        // that can have new characters added to it.
+        var parser = pipeline.InlineParsers.FindExact<EmphasisInlineParser>();
+
+        // If we find the parser and it doesn't already have the % character registered, we add
+        // a descriptor for 3 consecutive % signs. This is specific to the EmphasisInlineParser and
+        // is just used here as an example.
+        if (parser is not null && !parser.HasEmphasisChar('%'))
+        {
+            parser.EmphasisDescriptors.Add(new EmphasisDescriptor('%', 3, 3, false));
+        }
+    }
+
+    // This method is called by the pipeline before rendering, which is a separate operation from 
+    // parsing. This implementation is just here for the purpose of the example, in which we 
+    // daisy-chain a delegate specific to the EmphasisInlineRenderer to cause an unconscionable tag 
+    // to be inserted into the HTML output wherever a %%% annotated span was placed in the source.
+    public void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer)
+    {
+        if (renderer is not HtmlRenderer) return;
+
+        var emphasisRenderer = renderer.ObjectRenderers.FindExact<EmphasisInlineRenderer>();
+        if (emphasisRenderer is null) return;
+
+        var previousTag = emphasisRenderer.GetTag;
+        emphasisRenderer.GetTag = inline =>
+            (inline.DelimiterCount == 3 && inline.DelimiterChar == '%' ? "blink" : null)
+            ?? previousTag(inline);
+    }
+}
+```

doc/parsing-overview.md

@@ -0,0 +1,336 @@
+# Markdig Parsing
+
+Markdig provides efficient, regex-free parsing of markdown documents directly into an abstract syntax tree (AST). The AST is a representation of the markdown document's semantic constructs, which can be manipulated and explored programmatically.
+
+* This document contains a general overview of the parsing system and components and their use
+* The [Abstract Syntax Tree](parsing-ast.md) document contains a discussion of how Markdig represents the product of the parsing operation
+* The [Extensions/Parsers](parsing-extensions.md) document explores extensions and block/inline parsers within the context of extending Markdig's parsing capabilities
+
+## Introduction
+
+Markdig's parsing machinery consists of two main components at its surface: the `Markdown.Parse(...)` method and the `MarkdownPipeline` type.  The parsed document is represented by a `MarkdownDocument` object, which is a tree of objects derived from `MarkdownObject`, including block and inline elements. 
+
+The `Markdown` static class is the main entrypoint to the Markdig API. It contains the `Parse(...)` method, the main algorithm for parsing a markdown document. The `Parse(...)` method in turn uses a `MarkdownPipeline`, which is a sealed internal class which maintains some configuration information and the collections of parsers and extensions.  The `MarkdownPipeline` determines how the parser behaves and what its capabilities are.  The `MarkdownPipeline` can be modified with built-in as well as user developed extensions.
+
+### Glossary of Relevant Types
+
+The following is a table of some of the types relevant to parsing and mentioned in the related documentation. For an exhaustive list refer to API documentation (coming soon).
+
+|Type|Description|
+|-|-|
+|`Markdown`|Static class with the entry point to the parsing algorithm via the `Parse(...)` method|
+|`MarkdownPipeline`|Configuration object for the parser, contains collections of block and inline parsers and registered extensions|
+|`MarkdownPipelineBuilder`|Responsible for constructing the `MarkdownPipeline`, used by client code to configure pipeline options and behaviors|
+|`IMarkdownExtension`|Interface for [Extensions](#extensions-imarkdownextension) which alter the behavior of the pipeline, this is the standard mechanism for extending Markdig|
+|`BlockParser`|Base type for an individual parsing component meant to identify `Block` elements in the markdown source|
+|`InlineParser`|Base type for an individual parsing component meant to identify `Inline` elements within a `Block`|
+|`Block`|A node in the AST representing a markdown block element, can either be a `ContainerBlock` or a `LeafBlock`|
+|`Inline`|A node in the AST representing a markdown inline element|
+|`MarkdownDocument`|The root node of the AST produced by the parser, derived from `ContainerBlock`|
+|`MarkdownObject`|The base type of all `Block` and `Inline` derived objects (as well as `HtmlAttributes`)|
+
+### Simple Examples
+
+*The following are simple examples of parsing to help get you started, see the following sections for an in-depth explanation of the different parts of Markdig's parsing mechanisms*
+
+The `MarkdownPipeline` dictate how the parser will behave.  The `Markdown.Parse(...)` method will construct a default pipeline if none is provided.  A default pipeline will be CommonMark compliant but nothing else.
+
+```csharp
+var markdownText = File.ReadAllText("sample.md");
+
+// No pipeline provided means a default pipeline will be used
+var document = Markdown.Parse(markdownText);
+```
+
+Pipelines can be created and configured manually, however this must be done using a `MarkdownPipelineBuilder` object, which then is configured through a fluent interface composed of extension methods.  
+
+```csharp
+var markdownText = File.ReadAllText("sample.md");
+
+// Markdig's "UseAdvancedExtensions" option includes many common extensions beyond
+// CommonMark, such as citations, figures, footnotes, grid tables, mathematics
+// task lists, diagrams, and more.
+var pipeline = new MarkdownPipelineBuilder()
+    .UseAdvancedExtensions()
+    .Build();
+
+var document = Markdown.Parse(markdownText, pipeline);
+```
+
+Extensions can also be added individually:
+
+```csharp
+var markdownText = File.ReadAllText("sample.md");
+
+var pipeline = new MarkdownPipelineBuilder()
+    .UseCitations()
+    .UseFootnotes()
+    .UseMyCustomExtension()
+    .Build();
+
+var document = Markdown.Parse(markdownText, pipeline);
+```
+
+## Markdown.Parse and the MarkdownPipeline
+
+As metioned in the [Introduction](#introduction), Markdig's parsing machinery involves two surface components: the `Markdown.Parse(...)` method, and the `MarkdownPipeline` type.  The main parsing algorithm (not to be confused with individual `BlockParser` and `InlineParser` components) lives in the `Markdown.Parse(...)` static method. The `MarkdownPipeline` is responsible for configuring the behavior of the parser.
+
+These two components are covered in further detail in the following sections.
+
+### The MarkdownPipeline
+
+The `MarkdownPipeline` is a sealed internal class which dictates what features the parsing algorithm has.  The pipeline must be created by using a `MarkdownPipelineBuilder` as shown in the examples above.
+
+The `MarkdownPipeline` holds configuration information and collections of extensions and parsers.  Parsers fall into one of two categories:
+
+* Block Parsers (`BlockParser`)
+* Inline Parsers (`InlineParser`)
+
+Extensions are classes implementing `IMarkdownExtension` which are allowed to add to the list of parsers, or modify existing parsers and/or renderers. They are invoked to perform their mutations on the pipeline when the pipeline is built by the `MarkdownPipelineBuilder`.
+
+Lastly, the `MarkdownPipeline` contains a few extra elements:
+
+* A configuration setting determining whether or not trivial elements, referred to as *trivia*, (whitespace, extra heading characters, unescaped strings, etc) are to be tracked
+* A configuration setting determining whether or not nodes in the resultant abstract syntax tree will refer to their precise original locations in the source
+* An optional delegate which will be invoked when the document has been processed.
+* An optional `TextWriter` which will get debug logging from the parser
+
+### The Markdown.Parse Method
+
+`Markdown.Parse` is a static method which contains the overall parsing algorithm but not the actual parsing components, which instead are contained within the pipeline.
+
+The `Markdown.Parse(...)` method takes a string containing raw markdown and returns a `MarkdownDocument`, which is the root node in the abstract syntax tree.  The `Parse(...)` method optionally takes a pre-configured `MarkdownPipeline`, but if none is given will create a default pipeline which has minimal features.
+
+Within the `Parse(...)` method, the following sequence of operations occur:
+
+1. The block parsers contained in the pipeline are invoked on the raw markdown text, creating the initial tree of block elements
+2. If the pipeline is configured to track markdown trivia (trivial/non-contributing elements), the blocks are expanded to absorb neighboring trivia
+3. The inline parsers contained in the pipeline are now invoked on the blocks, populating the inline elements of the abstract syntax tree
+4. If a delegate has been configured for when the document has completed processing, it is now invoked
+5. The abstract syntax tree (`MarkdownDocument` object) is returned
+
+## The Pipeline Builder and Extensions
+
+The `MarkdownPipeline` determines the behavior and capabilities of the parser, and *extensions* added via the `MarkdownPipelineBuilder` determine the configuration of the pipeline.  
+
+This section discusses the pipeline builder and the concept of *extensions* in more detail.
+
+### Extensions (IMarkdownExtension)
+
+***Note**: This section discusses how to consume extensions by adding them to pipeline. For a discussion on how to implement an extension, refer to the [Extensions/Parsers](parsing-extensions.md) document.*
+
+Extensions are the primary mechanism for modifying the parsers in the pipeline.
+
+An extension is any class which implements the `IMarkdownExtension` interface found in [IMarkdownExtension.cs](https://github.com/xoofx/markdig/blob/master/src/Markdig/IMarkdownExtension.cs). This interface consists solely of two `Setup(...)` overloads, which both take a `MarkdownPipelineBuilder` as the first argument.
+
+When the `MarkdownPipelineBuilder.Build()` method is invoked as the final stage in pipeline construction, the builder runs through the list of registered extensions in order and calls the `Setup(...)` method on each of them.  The extension then has full access to modify both the parser collections themselves (by adding new parsers to it), or to find and modify existing parsers.  
+
+Because of this, *some* extensions may need to be ordered in relation to others, for instance if they modify a parser that gets added by a different extension. The `OrderedList<T>` class contains convenience methods to this end, which aid in finding other extensions by type and then being able to added an item before or after them.
+
+### The MarkdownPipelineBuilder
+
+Because the `MarkdownPipeline` is a sealed internal class, it cannot (and *should* not be attempted to) be created directly.  Rather, the `MarkdownPipelineBuilder` manages the requisite construction of the pipeline after the configuration has been provided by the client code.
+
+As discussed in the [section above](#the-markdownpipeline), the `MarkdownPipeline` primarily consists of a collection of block parsers and a collection of inline parsers, which are provided to the `Markdown.Parse(...)` method and thus determine its features and behavior.  Both the collections and some of the parsers themselves are mutable, and the mechanism of mutation is the `Setup(...)` method of the `IMarkdownExtension` interface.  This is covered in more detail in the section on [Extensions](#extensions-imarkdownextension).
+
+#### The Fluent Interface
+
+A collection of extension methods in the [MarkdownExtensions.cs](https://github.com/xoofx/markdig/blob/master/src/Markdig/MarkdownExtensions.cs) source file provides a convenient fluent API for the configuration of the pipeline builder.  This should be considered the standard way of configuring the builder.
+
+##### Configuration Options
+
+There are several extension methods which apply configurations to the builder which change settings in the pipeline outside of the use of typical extensions. 
+
+|Method|Description|
+|-|-|
+|`.ConfigureNewLine(...)`|Takes a string which will serve as the newline delimiter during parsing|
+|`.DisableHeadings()`|Disables the parsing of ATX and Setex headings|
+|`.DisableHtml()`|Disables the parsing of HTML elements|
+|`.EnableTrackTrivia()`|Enables the tracking of trivia (trivial elements like whitespace)|
+|`.UsePreciseSourceLocation()`|Maps syntax objects to their precise location in the original source, such as would be required for syntax highlighting|
+
+```csharp
+var builder = new MarkdownPipelineBuilder()
+    .ConfigureNewLine("\r\n")
+    .DisableHeadings()
+    .DisableHtml()
+    .EnableTrackTrivia()
+    .UsePreciseSourceLocation();
+
+var pipeline = builder.Build();
+```
+
+##### Adding Extensions
+
+All extensions which ship with Markdig can be added through a dedicated fluent method, while user code which implements the `IMarkdownExtension` interface can be added with one of the `Use()` methods, or via a custom extension method implemented in the client code.
+
+Refer to [MarkdownExtensions.cs](https://github.com/xoofx/markdig/blob/master/src/Markdig/MarkdownExtensions.cs) for a full list of extension methods:
+
+```csharp
+var builder = new MarkdownPipelineBuilder()
+    .UseFootnotes()
+    .UseFigures();
+```
+
+For custom/user-provided extensions, the `Use<TExtension>(...)` methods allow either a type to be directly added or an already constructed instance to be put into the extension container. Internally they will prevent two of the same type of extension from being added to the container.
+
+```csharp
+public class MyExtension : IMarkdownExtension 
+{
+    // ...
+}
+
+// Only works if MyExtension has an empty constructor (aka new())
+var builder = new MarkdownPipelineBuilder()
+    .Use<MyExtension>();
+```
+
+Alternatively:
+
+```csharp
+public class MyExtension : IMarkdownExtension 
+{
+    public MyExtension(object someConfigurationObject) { /* ... */ }
+    // ...
+}
+
+var instance = new MyExtension(configData);
+
+var builder = new MarkdownPipelineBuilder()
+    .Use(instance);
+```
+
+##### Adding Extensions with the Configure Method
+
+The `MarkdownPipelineBuilder` has one additional method for the configuration of extensions worth mentioning: the `Configure(...)` method, which takes a `string?` of `+` delimited tokens specifying which extensions should be dynamically configured.  This is a convenience method for the configuration of pipelines whose extensions are only known at runtime.
+
+Refer to [MarkdownExtensions.cs's `Configure(...)`](https://github.com/xoofx/markdig/blob/983187eace6ba02ee16d1443c387267ad6e78f58/src/Markdig/MarkdownExtensions.cs#L538) code for the full list of extensions.
+
+
+```csharp
+var builder = new MarkdownPipelineBuilder()
+    .Configure("common+footnotes+figures");
+
+var pipeline = builder.Build();
+```
+
+#### Manual Configuration
+
+Internally, the fluent interface wraps manual operations on the three primary collections:
+
+* `MarkdownPipelineBuilder.BlockParsers` - this is an `OrderedList<BlockParser>` of the block parsers
+* `MarkdownPipelineBuilder.InlineParsers` - this is an `OrderedList<InlineParser>` of the inline element parsers
+* `MarkdownPipelineBuilder.Extensions` - this is an `OrderedList<IMarkdownExtension>` of the extensions
+
+All three collections are `OrderedList<T>`, which is a collection type custom to Markdig which contains special methods for finding and inserting derived types.  With the builder created, manual configuration can be performed by accessing these collections and their elements and modifying them as necessary.  
+
+***Warning**: be aware that it should not be necessary to directly modify either the `BlockParsers` or the `InlineParsers` collections directly during the pipeline configuration. Rather, these can and should be modified whenever possible through the `Setup(...)` method of extensions, which will be deferred until the pipeline is actually built and will allow for ordering such that operations dependent on other operations can be accounted for.*
+
+## Block and Inline Parsers
+
+Let's dive deeper into the parsing system.  With a configured pipeline, the `Markdown.Parse` method will run through two two conceptual passes to produce the abstract syntax tree.
+
+1. First, `BlockProcessor.ProcessLine` is called on the file's lines, one by one, trying to identify block elements in the source
+2. Next, an `InlineProcessor` is created or borrowed and run on each block to identify inline elements.
+
+These two conceptual operations dictate Markdig's two types of parsers, both of which derive from `ParserBase<TProcessor>`. 
+
+Block parsers, derived from `BlockParser`, identify block elements from lines in the source text and push them onto the abstract syntax tree.  Inline parsers, derived from `InlineParser`, identify inline elements from `LeafBlock` elements and push them into an attached container: the `ContainerInline? LeafBlock.Inline` property.  
+
+Both inline and block parsers are regex-free, and instead work on finding opening characters and then making fast read-only views into the source text.
+
+### Block Parser
+
+**(The contents of this section I am very unsure of, this is from my reading of the code but I could use some guidance here)**
+
+**(Does `CanInterrupt` specifically refer to interrupting a paragraph block?)**
+
+In order to be added to the parsing pipeline, all block parsers must be derived from `BlockParser`.
+
+Internally, the main parsing algorithm will be stepping through the source text, using the `HasOpeningCharacter(char c)` method of the block parser collection to pre-identify parsers which *could* be opening a block at a given position in the text based on the active character.  Thus any derived implementation needs to set the value of the `char[]? OpeningCharacter` property with the initial characters that might begin the block.
+
+If a parser can potentially open a block at a place in the source text it should expect to have the `TryOpen(BlockProcessor processor)` method called.  This is a virtual method that must be implemented on any derived class.  The `BlockProcessor` argument is a reference to an object which stores the current state of parsing and the position in the source.
+
+**(What are the rules concerning how the `BlockState` return type should work for `TryOpen`? I see examples returning `None`, `Continue`, `BreakDiscard`, `ContinueDiscard`.  How does the return value change the algorithm behavior?)**
+
+**(Should a new block always be pushed into `processor.NewBlocks` in the `TryOpen` method?)**
+
+As the main parsing algorithm moves forward, it will then call `TryContinue(...)` on blocks that were opened in `TryOpen(..)`. 
+
+**(Is this where/how you close a block? Is there anything that needs to be done to perform that beyond `block.UpdateSpanEnd` and returning `BlockState.Break`?)**
+
+
+### Inline Parsers
+
+Inline parsers extract inline markdown elements from the source, but their starting point is the text of each individual `LeafBlock` produced by the block parsing process.  To understand the role of each inline parser it is necessary to first understand the inline parsing process as a whole.
+
+#### The Inline Parsing Process
+
+After the block parsing process has occurred, the abstract syntax tree of the document has been populated only with block elements, starting from the root `MarkdownDocument` node and ending with the individual `LeafBlock` derived block elements, most of which will be `ParagraphBlocks`, but also include things like `CodeBlocks`, `HeadingBlocks`, `FigureCaptions`, and so on.
+
+At this point, the parsing machinery will iterate through each `LeafBlock` one by one, creating and assigning its `LeafBlock.Inline` property with an empty `ContainerInline`, and then sweeping through the `LeafBlock`'s text running the inline parsers.  This occurs by the following process:
+
+Starting at the first character of the text it will run through all of its `InlineParser` objects which have that character as a possible opening character for the type of inline they extract.  The parsers will run in order (as such ordering is the *only* way which conflicts between parsers are resolved, and thus is important to the overall behavior of the parsing system) and the `Match(...)` method will be called on each candidate parser, in order, until one of them returns `true`.
+
+The `Match(...)` method will be passed a slice of the text beginning at the *specific character* being processed and running until the end of the `LeafBlock`'s complete text.  If the parser can create an `Inline` element it will do so and return `true`, otherwise it will return `false`.  The parser will store the created `Inline` object in the processor's `InlineProcessor.Inline` property, which as passed into the `Match(...)` method as an argument.  The parser will also advance the start of the working `StringSlice` by the characters consumed in the match.
+
+* If the parser has created an inline element and returned `true`, that element is pushed into the deepest open `ContainerInline`
+* If `false` was returned, a default `LiteralInlineParser` will run instead:
+    * If the `InlineProcessor.Inline` property already has an existing `LiteralInline` in it, these characters will be added to the existing `LiteralInline`, effectively growing it
+    * If no `LiteralInline` exists in the `InlineProcessor.Inline` property, a new one will be created containing the consumed characters and pushed into the deepest open `ContainerInline`
+
+After that, the working text of the `LeafBlock` has been conceptually shortened by the advancing start of the working `StringSlice`, moving the starting character forward.  If there is still text remaining, the process repeats from the new starting character until all of the text is consumed.
+
+At this point, when all of the source text from the `LeafBlock` has been consumed, a post-processing step occurs.  `InlineParser` objects in the pipeline which also implement `IPostInlineProcessor` are invoked on the `LeafBlock`'s root `ContainerInline`.  This, for example, is the mechanism by which the unstructured output of the `EmphasisInlineParser` is then restructured into cleanly nested `EmphasisInline` and `LiteralInline` elements.
+
+
+#### Responsibilities of an Inline Parser
+
+Like the block parsers, an inline parser must provide an array of opening characters with the `char[]? OpeningCharacter` property.
+
+However, inline parsers only require one other method, the `Match(InlineProcessor processor, ref StringSlice slice)` method, which is expected to determine if a match for the related inline is located at the starting character of the slice.
+
+Within the `Match` method a parser should:
+
+1. Determine if a match begins at the starting character of the `slice` argument
+2. If no match exists, the method should return `false` and not advance the `Start` property of the `slice` argument
+3. If a match does exist, perform the following actions: 
+    * Instantiate the appropriate `Inline` derived class and assign it to the processor argument with `processor.Inline = myInlineObject`
+    * Advance the `Start` property of the `slice` argument by the number of characters contained in the match, for example by using the `NextChar()`, `SkipChar()`, or other helper methods of the `StringSlice` class
+    * Return `true`
+
+While parsing, the `InlineProcessor` performing the processing, which is available to the `Match` function through the `processor` argument, contains a number of properties which can be used to access the current state of parsing.  For example, the `processor.Inline` property is the mechanism for returning a new inline element, but before assignment it contains the last created inline, which in turn can be accessed for its parents.
+
+Additionally, in the case of inlines which can be expected to contain other inlines, a possible strategy is to inject an inline element derived from `DelimiterInline` when the opening delimiter is detected, then to replace the opening delimiter with the final desired element when the closing delimiter is found.  This is the strategy used by the `LinkInlineParser`, for example.  In such cases the tools described in the next section, such as the `ReplaceBy` method, can be used.  Note that if this method is used the post-processing should be invoked on the `InlineProcessor` in order to finalize any emphasis elements.  For example, in the following code adapted from the `LinkInlineParser`:
+
+```csharp
+var parent = processor.Inline?.FirstParentOfType<MyDelimiterInline>();
+if (parent is null) return;
+
+var myInline = new MySpecialInline { /* set span and other parameters here */ };
+
+// Replace the delimiter inline with the final inline type, adopting all of its children
+parent.ReplaceBy(myInline);
+
+// Notifies processor as we are creating an inline locally
+processor.Inline = myInline;
+
+// Process emphasis delimiters
+processor.PostProcessInlines(0, myInline, null, false);
+```
+
+#### Inline Post-Processing
+
+The purpose of post-processing inlines is typically to re-structure inline elements after the initial parsing is complete and the entire structure of the inline elements within a parent container is now available in a way it was not during the parsing process.  Generally this consists of removing, replacing, and re-ordering `Inline` elements.
+
+To this end, the `Inline` abstract base class contains several helper methods intended to allow manipulation of inline elements during the post-processing phase.
+
+|Method|Purpose|
+|-|-|
+|`InsertAfter(...)`|Takes a new inline as an argument and inserts it into the same parent container after this instance|
+|`InsertBefore(...)`|Takes a new inline as an argument and inserts it into the same parent container before this instance|
+|`Remove()`|Removes this inline from its parent container|
+|`ReplaceBy(...)`|Removes this instance and replaces it with a new inline specified in the argument. Has an option to move all of the original inline's children into the new inline.|
+
+Additionally, the `PreviousSibling` and `NextSibling` properties can be used to determine the siblings of an inline element within its parent container.  The `FirstParentOfType<T>()` method can be used to search for a parent element, which is often useful when searching for `DelimiterInline` derived elements, which are implemented as containers.
+

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license.txt

@@ -1,4 +1,4 @@
-Copyright (c) 2016, Alexandre Mutel
+Copyright (c) 2018-2019, Alexandre Mutel
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification

readme.md

@@ -1,86 +1,167 @@
-# Markdig  [![NuGet](https://img.shields.io/nuget/v/Markdig.svg)](https://www.nuget.org/packages/Markdig/)
+# Markdig [![ci](https://github.com/xoofx/markdig/actions/workflows/ci.yml/badge.svg)](https://github.com/xoofx/markdig/actions/workflows/ci.yml) [![Coverage Status](https://coveralls.io/repos/github/xoofx/markdig/badge.svg?branch=master)](https://coveralls.io/github/xoofx/markdig?branch=master) [![NuGet](https://img.shields.io/nuget/v/Markdig.svg)](https://www.nuget.org/packages/Markdig/) [![Donate](https://www.paypalobjects.com/en_US/i/btn/btn_donate_SM.gif)](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=FRGHXBTP442JL)
 
-Markdig is a fast, powerfull, [CommonMark](http://commonmark.org/) compliant, extensible Markdown processor for .NET.
+<img align="right" width="160px" height="160px" src="img/markdig.png">
+
+Markdig is a fast, powerful, [CommonMark](https://commonmark.org/) compliant, extensible Markdown processor for .NET.
 
 > NOTE: The repository is under construction. There will be a dedicated website and proper documentation at some point!
 
+You can **try Markdig online** and compare it to other implementations on [babelmark3](https://babelmark.github.io/?text=Hello+**Markdig**!)
+
 ## Features
 
-- **Very fast parser** (no-regexp), very lightweight in terms of GC pressure. See benchmarks
-- **Abstract Syntax Tree**
+- **Very fast parser and html renderer** (no-regexp), very lightweight in terms of GC pressure. See benchmarks
+- **Abstract Syntax Tree** with precise source code location for syntax tree, useful when building a Markdown editor.
+  - Checkout [Markdown Editor v2 for Visual Studio 2022](https://marketplace.visualstudio.com/items?itemName=MadsKristensen.MarkdownEditor2) powered by Markdig!
 - Converter to **HTML**
-- Passing more than **600+ tests** from the latest [CommonMark specs](http://spec.commonmark.org/)
+- Passing more than **600+ tests** from the latest [CommonMark specs (0.31.2)](https://spec.commonmark.org/)
 - Includes all the core elements of CommonMark:
-  - including GFM fenced code blocks. 
+  - including **GFM fenced code blocks**.  
 - **Extensible** architecture
-- Built-in with **18+ extensions**, including:
-  - **Abbreviations** (inspired from [PHP Markdown Extra - Abbreviations](https://michelf.ca/projects/php-markdown/extra/#abbr))
-  - **Auto-identifiers** for headings (similar to [Pandoc](http://pandoc.org/README.html#extension-auto_identifiers)
-  - **Bootstrap** class (to output bootstrap class)
-  - **Citation** text by enclosing `""...""` (inspired by this [CommonMark discussion ](https://talk.commonmark.org/t/referencing-creative-works-with-cite/892))
-  - **Custom containers** similar to fenced code block `:::` for generating a proper `<div>...</div>` instead (inspired by this [CommonMark discussion ](https://talk.commonmark.org/t/custom-container-for-block-and-inline/2051))
-  - **Definition lists** (inspired from [PHP Markdown Extra - Definitions Lists](https://michelf.ca/projects/php-markdown/extra/#def-list))
-  - **Emoji** support (inspired from [Markdown-it](https://markdown-it.github.io/))
-  - **Extra emphasis** (inspired from [Pandoc](http://pandoc.org/README.html#strikeout) and [Markdown-it](https://markdown-it.github.io/)) 
+  - Even the core Markdown/CommonMark parsing is pluggable, so it allows to disable builtin Markdown/Commonmark parsing (e.g [Disable HTML parsing](https://github.com/lunet-io/markdig/blob/7964bd0160d4c18e4155127a4c863d61ebd8944a/src/Markdig/MarkdownExtensions.cs#L306)) or change behaviour (e.g change matching `#` of a headers with `@`)   
+- [**Roundtrip support**](./src/Markdig/Roundtrip.md): Parses trivia (whitespace, newlines and other characters) to support lossless parse ⭢ render roundtrip. This enables changing markdown documents without introducing undesired trivia changes.
+- Built-in with **20+ extensions**, including:
+  - 2 kind of tables:
+    - [**Pipe tables**](src/Markdig.Tests/Specs/PipeTableSpecs.md) (inspired from GitHub tables and [PanDoc - Pipe Tables](https://pandoc.org/MANUAL.html#extension-pipe_tables))
+    - [**Grid tables**](src/Markdig.Tests/Specs/GridTableSpecs.md) (inspired from [Pandoc - Grid Tables](https://pandoc.org/MANUAL.html#extension-grid_tables)) 
+  - [**Extra emphasis**](src/Markdig.Tests/Specs/EmphasisExtraSpecs.md) (inspired from [Pandoc - Emphasis](https://pandoc.org/MANUAL.html#strikeout) and [Markdown-it](https://markdown-it.github.io/)) 
     - strike through `~~`,
     - Subscript `~`
     - Superscript `^` 
     - Inserted `++`
     - Marked `==`
-  - **Figures** (inspired from this [CommonMark discussion](https://talk.commonmark.org/t/image-tag-should-expand-to-figure-when-used-with-title/265/5))
-  - **Footers** (inspired from this [CommonMark discussion](https://talk.commonmark.org/t/syntax-for-footer/2070))
-  - **Footnotes** (inspired from [PHP Markdown Extra - Footnotes](https://michelf.ca/projects/php-markdown/extra/#footnotes))
-  - **Special attributes** or attached HTML attributes (inspired from [PHP Markdown Extra - Footnotes](https://michelf.ca/projects/php-markdown/extra/#spe-attr))
-  - **Soft lines as hard lines**
-  - **Extra bullet lists**, supporting alpha bullet `a.` `b.` and roman bullet (`i`, `ii`...etc.)
-  - **Mathematics**/Latex extension by enclosing `$$` for block and `$` for inline math (inspired from this [CommonMark discussion](https://talk.commonmark.org/t/mathematics-extension/457/31))
-  - **Embed player** for media url (youtube, vimeo, mp4...etc.) (inspired from this [CommonMark discussion](https://talk.commonmark.org/t/embedded-audio-and-video/441))
-  - **SmartyPants** (inspired from [Daring Fireball - SmartyPants](https://daringfireball.net/projects/smartypants/))
-  - Tables:
-    - **Pipe tables** (inspired from Kramdown/[PanDoc](http://pandoc.org/README.html#pipe_tables))
-    - **Grid tables** (inspired from [Pandoc](http://pandoc.org/README.html#grid_tables)) 
-- Compatible with .NET 3.5, 4.0+ and .NET Core (`netstandard1.1+`)
+  - [**Special attributes**](src/Markdig.Tests/Specs/GenericAttributesSpecs.md) or attached HTML attributes (inspired from [PHP Markdown Extra - Special Attributes](https://michelf.ca/projects/php-markdown/extra/#spe-attr))
+  - [**Definition lists**](src/Markdig.Tests/Specs/DefinitionListSpecs.md) (inspired from [PHP Markdown Extra - Definitions Lists](https://michelf.ca/projects/php-markdown/extra/#def-list))
+  - [**Footnotes**](src/Markdig.Tests/Specs/FootnotesSpecs.md) (inspired from [PHP Markdown Extra - Footnotes](https://michelf.ca/projects/php-markdown/extra/#footnotes))
+  - [**Auto-identifiers**](src/Markdig.Tests/Specs/AutoIdentifierSpecs.md) for headings (similar to [Pandoc - Auto Identifiers](https://pandoc.org/MANUAL.html#extension-auto_identifiers))
+  - [**Auto-links**](src/Markdig.Tests/Specs/AutoLinks.md) generates links if a text starts with `http://` or `https://` or `ftp://` or `mailto:` or `www.xxx.yyy`
+  - [**Task Lists**](src/Markdig.Tests/Specs/TaskListSpecs.md)  inspired from [Github Task lists](https://github.com/blog/1375-task-lists-in-gfm-issues-pulls-comments).
+  - [**Extra bullet lists**](src/Markdig.Tests/Specs/ListExtraSpecs.md), supporting alpha bullet `a.` `b.` and roman bullet (`i`, `ii`...etc.)
+  - [**Media support**](src/Markdig.Tests/Specs/MediaSpecs.md) for media url (youtube, vimeo, mp4...etc.) (inspired from this [CommonMark discussion](https://talk.commonmark.org/t/embedded-audio-and-video/441))
+  - [**Abbreviations**](src/Markdig.Tests/Specs/AbbreviationSpecs.md) (inspired from [PHP Markdown Extra - Abbreviations](https://michelf.ca/projects/php-markdown/extra/#abbr))
+  - [**Citation**](src/Markdig.Tests/Specs/FigureFooterAndCiteSpecs.md) text by enclosing `""...""` (inspired by this [CommonMark discussion ](https://talk.commonmark.org/t/referencing-creative-works-with-cite/892))
+  - [**Custom containers**](src/Markdig.Tests/Specs/CustomContainerSpecs.md) similar to fenced code block `:::` for generating a proper `<div>...</div>` instead (inspired by this [CommonMark discussion ](https://talk.commonmark.org/t/custom-container-for-block-and-inline/2051))
+  - [**Figures**](src/Markdig.Tests/Specs/FigureFooterAndCiteSpecs.md) (inspired from this [CommonMark discussion](https://talk.commonmark.org/t/image-tag-should-expand-to-figure-when-used-with-title/265/5))
+  - [**Footers**](src/Markdig.Tests/Specs/FigureFooterAndCiteSpecs.md) (inspired from this [CommonMark discussion](https://talk.commonmark.org/t/syntax-for-footer/2070))
+  - [**Mathematics**](src/Markdig.Tests/Specs/MathSpecs.md)/Latex extension by enclosing `$$` for block and `$` for inline math (inspired from this [CommonMark discussion](https://talk.commonmark.org/t/mathematics-extension/457/31))
+  - [**Soft lines as hard lines**](src/Markdig.Tests/Specs/HardlineBreakSpecs.md)
+  - [**Emoji**](src/Markdig.Tests/Specs/EmojiSpecs.md) support (inspired from [Markdown-it](https://markdown-it.github.io/))
+  - [**SmartyPants**](src/Markdig.Tests/Specs/SmartyPantsSpecs.md) (inspired from [Daring Fireball - SmartyPants](https://daringfireball.net/projects/smartypants/))
+  - [**Bootstrap**](src/Markdig.Tests/Specs/BootstrapSpecs.md) class (to output bootstrap class)
+  - [**Diagrams**](src/Markdig.Tests/Specs/DiagramsSpecs.md) extension whenever a fenced code block contains a special keyword, it will be converted to a div block with the content as-is (currently, supports [`mermaid`](https://mermaid.js.org) and [`nomnoml`](https://github.com/skanaar/nomnoml) diagrams)
+  - [**YAML Front Matter**](src/Markdig.Tests/Specs/YamlSpecs.md) to parse without evaluating the front matter and to discard it from the HTML output (typically used for previewing without the front matter in MarkdownEditor)
+  - [**JIRA links**](src/Markdig.Tests/Specs/JiraLinks.md) to automatically generate links for JIRA project references (Thanks to @clarkd: https://github.com/clarkd/MarkdigJiraLinker)
+- Starting with Markdig version `0.20.0+`, Markdig is compatible only with `NETStandard 2.0`, `NETStandard 2.1`, `NETCoreApp 2.1` and `NETCoreApp 3.1`.
+
+If you are looking for support for an old .NET Framework 3.5 or 4.0, you can download Markdig `0.18.3`.
 	
+### Third Party Extensions
+
+- [**WPF/XAML Markdown Renderer**: `markdig.wpf`](https://github.com/Kryptos-FR/markdig.wpf)
+- [**WPF/XAML Markdown Renderer**: `Neo.Markdig.Xaml`](https://github.com/neolithos/NeoMarkdigXaml)
+- [**Syntax highlighting**: `Markdig.SyntaxHighlighting`](https://github.com/RichardSlater/Markdig.SyntaxHighlighting)
+- [**Syntax highlighting using ColorCode-Universal**: `Markdown.ColorCode`](https://github.com/wbaldoumas/markdown-colorcode)
+- [**Syntax highlighting using Prism.js**: `WebStoating.Markdig.Prism`](https://github.com/ilich/Markdig.Prism)
+- [**Embedded C# scripting**: `Markdig.Extensions.ScriptCs`](https://github.com/macaba/Markdig.Extensions.ScriptCs)
+
+## Documentation
+
+> The repository is under construction. There will be a dedicated website and proper documentation at some point!
+
+While there is not yet a dedicated documentation, you can find from the [specs documentation](src/Markdig.Tests/Specs/readme.md) how to use these extensions.
+
+In the meantime, you can have a "behind the scene" article about Markdig in my blog post ["Implementing a Markdown Engine for .NET"](https://xoofx.github.io/blog/2016/06/13/implementing-a-markdown-processor-for-dotnet/)
+
 ## Download
 
 Markdig is available as a NuGet package: [![NuGet](https://img.shields.io/nuget/v/Markdig.svg)](https://www.nuget.org/packages/Markdig/)
 
+Also [Markdig.Signed](https://www.nuget.org/packages/Markdig.Signed/) NuGet package provides signed assemblies.
+
 ## Usage
 
-The main entry point for the API is the `Markdown` class:
+The main entry point for the API is the `Markdig.Markdown` class:
 
 By default, without any options, Markdig is using the plain CommonMark parser:
 
 ```csharp
-var result = Markdown.ToHtml("This is a text with some **emphasis**");
+var result = Markdown.ToHtml("This is a text with some *emphasis*");
 Console.WriteLine(result);   // prints: <p>This is a text with some <em>emphasis</em></p>
 ```
 
-In order to activate all extensions (except Emoji)
+In order to activate most of all advanced extensions (except Emoji, SoftLine as HardLine, Bootstrap, YAML Front Matter, JiraLinks and SmartyPants)
 
 ```csharp
-var result = Markdown.ToHtml("This is a text with some **emphasis**", new MarkdownPipeline().UseAllExtensions());
+// Configure the pipeline with all advanced extensions active
+var pipeline = new MarkdownPipelineBuilder().UseAdvancedExtensions().Build();
+var result = Markdown.ToHtml("This is a text with some *emphasis*", pipeline);
 ```
 
-You can have a look at the [MarkdownPipeline](https://github.com/lunet-io/markdig/blob/src/Markdig/MarkdownPipeline.cs) file that describes all actionable extensions.
+[Try it online!](https://dotnetfiddle.net/GoZXyI)
+
+You can have a look at the [MarkdownExtensions](https://github.com/lunet-io/markdig/blob/master/src/Markdig/MarkdownExtensions.cs) that describes all actionable extensions (by modifying the MarkdownPipeline)
+
+## Contributing
+
+Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated. For detailed contributing guidelines, please see [contributing.md](contributing.md).
+
+## Build
+
+In order to build Markdig, you need to install [.NET 6.0](https://dotnet.microsoft.com/en-us/download)
 
 ## License
 
-This software is released under the [BSD-Clause 2 license](http://opensource.org/licenses/BSD-2-Clause).
+This software is released under the [BSD-Clause 2 license](https://github.com/lunet-io/markdig/blob/master/license.txt).
 
+
+## Benchmarking
+
+The latest benchmark was collected on April 23 2022, against the following implementations:
+
+- [Markdig](https://github.com/lunet-io/markdig) (version: 0.30.2): itself
+- [cmark](https://github.com/commonmark/cmark) (version: 0.30.2): Reference C implementation of CommonMark, no support for extensions
+- [CommonMark.NET(master)](https://github.com/Knagis/CommonMark.NET) (version: 0.15.1): CommonMark implementation for .NET, no support for extensions, port of cmark, deprecated.
+- [MarkdownSharp](https://github.com/Kiri-rin/markdownsharp) (version: 2.0.5): Open source C# implementation of Markdown processor, as featured previously on Stack Overflow, regexp based.
+
+```
+// * Summary *
+
+BenchmarkDotNet=v0.13.1, OS=Windows 10.0.22000
+AMD Ryzen 9 5950X, 1 CPU, 32 logical and 16 physical cores
+.NET SDK=6.0.202
+  [Host]     : .NET 6.0.4 (6.0.422.16404), X64 RyuJIT
+  DefaultJob : .NET 6.0.4 (6.0.422.16404), X64 RyuJIT
+
+
+|            Method |       Mean |     Error |    StdDev |
+|------------------ |-----------:|----------:|----------:|
+|           markdig |   1.979 ms | 0.0221 ms | 0.0185 ms |
+|             cmark |   2.571 ms | 0.0081 ms | 0.0076 ms |
+|    CommonMark.NET |   2.016 ms | 0.0169 ms | 0.0158 ms |
+|     MarkdownSharp | 221.455 ms | 1.4442 ms | 1.3509 ms |
+```
+
+- Markdig is roughly **x100 times faster than MarkdownSharp**
+- **20% faster than the reference cmark C implementation** 
+
+## Sponsors
+
+Supports this project with a monthly donation and help me continue improving it. \[[Become a sponsor](https://github.com/sponsors/xoofx)\]
+
+[<img src="https://github.com/lilith.png?size=200" width="64px;" style="border-radius: 50%" alt="lilith"/>](https://github.com/lilith) Lilith River, author of [Imageflow Server, an easy on-demand
+image editing, optimization, and delivery server](https://github.com/imazen/imageflow-server)
+
+## Credits
+
+Thanks to the fantastic work done by [John Mac Farlane](https://johnmacfarlane.net/) for the CommonMark specs and all the people involved in making Markdown a better standard!
+
+This project would not have been possible without this huge foundation.
+
+Thanks also to the project [BenchmarkDotNet](https://github.com/PerfDotNet/BenchmarkDotNet) that makes benchmarking so easy to setup!
+
+Some decoding part (e.g HTML [EntityHelper.cs](https://github.com/lunet-io/markdig/blob/master/src/Markdig/Helpers/EntityHelper.cs)) have been re-used from [CommonMark.NET](https://github.com/Knagis/CommonMark.NET)
+
+Thanks to the work done by @clarkd on the [JIRA Link extension](https://github.com/clarkd/MarkdigJiraLinker), now included with this project!
 ## Author
 
-Alexandre MUTEL aka [xoofx](http://xoofx.com)
-
-
-
-
-
-
-
-
-
-
-
-
-
+Alexandre MUTEL aka [xoofx](https://xoofx.github.io/)

src/Directory.Packages.props

@@ -0,0 +1,23 @@
+<Project>
+  <PropertyGroup>
+    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+    <CentralPackageTransitivePinningEnabled>false</CentralPackageTransitivePinningEnabled>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageVersion Include="BenchmarkDotNet" Version="0.14.0" />
+    <PackageVersion Include="BenchmarkDotNet.Diagnostics.Windows" Version="0.14.0" />
+    <PackageVersion Include="CommonMark.NET" Version="0.15.1" />
+    <PackageVersion Include="Markdown" Version="2.2.1" />
+    <PackageVersion Include="MarkdownSharp" Version="2.0.5" />
+    <PackageVersion Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.23.0" />
+    <PackageVersion Include="Microsoft.Diagnostics.Runtime" Version="3.1.512801" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
+    <PackageVersion Include="MinVer" Version="6.0.0" />
+    <PackageVersion Include="NUnit" Version="4.4.0" />
+    <PackageVersion Include="NUnit3TestAdapter" Version="5.2.0" />
+    <PackageVersion Include="SharpFuzz" Version="2.2.0" />
+  </ItemGroup>
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net462' OR '$(TargetFramework)' == 'netstandard2.0'">
+    <PackageVersion Include="System.Memory" Version="4.6.3" />
+  </ItemGroup>
+</Project>

src/Markdig.Benchmarks/CommonMarkLib.cs

@@ -1,40 +1,38 @@
-// Copyright (c) Alexandre Mutel. All rights reserved.
+// Copyright (c) Alexandre Mutel. All rights reserved.
 // This file is licensed under the BSD-Clause 2 license. 
 // See the license.txt file in the project root for more information.
 
-using System;
 using System.Runtime.InteropServices;
 using System.Text;
 
-namespace Testamina.Markdig.Benchmarks
-{
-    public static class CommonMarkLib
-    {
-        public static string ToHtml(string text)
-        {
-            unsafe
-            {
-                var textAsArray = Encoding.UTF8.GetBytes(text);
+namespace Testamina.Markdig.Benchmarks;
 
-                fixed (void* ptext = textAsArray)
+public static class CommonMarkLib
+{
+    public static string ToHtml(string text)
+    {
+        unsafe
+        {
+            var textAsArray = Encoding.UTF8.GetBytes(text);
+
+            fixed (void* ptext = textAsArray)
+            {
+                var ptr = (byte*)cmark_markdown_to_html(new IntPtr(ptext), text.Length);
+                int length = 0;
+                while (ptr[length] != 0)
                 {
-                    var ptr = (byte*)cmark_markdown_to_html(new IntPtr(ptext), text.Length);
-                    int length = 0;
-                    while (ptr[length] != 0)
-                    {
-                        length++;
-                    }
-                    var buffer = new byte[length];
-                    Marshal.Copy(new IntPtr(ptr), buffer, 0, length);
-                    var result = Encoding.UTF8.GetString(buffer);
-                    Marshal.FreeHGlobal(new IntPtr(ptr));
-                    return result;
+                    length++;
                 }
+                var buffer = new byte[length];
+                Marshal.Copy(new IntPtr(ptr), buffer, 0, length);
+                var result = Encoding.UTF8.GetString(buffer);
+                Marshal.FreeHGlobal(new IntPtr(ptr));
+                return result;
             }
         }
-
-        // char *cmark_markdown_to_html(const char *text, size_t len, int options);
-        [DllImport("cmark", CallingConvention = CallingConvention.Cdecl)]
-        private static extern IntPtr cmark_markdown_to_html(IntPtr charBuffer, int len, int options = 0);
     }
+
+    // char *cmark_markdown_to_html(const char *text, size_t len, int options);
+    [DllImport("cmark", CallingConvention = CallingConvention.Cdecl)]
+    private static extern IntPtr cmark_markdown_to_html(IntPtr charBuffer, int len, int options = 0);
 }

src/Markdig.Benchmarks/Markdig.Benchmarks.csproj

@@ -1,103 +1,32 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <ProjectGuid>{6A19F040-BC7C-4283-873A-177B5324F1ED}</ProjectGuid>
+    <TargetFramework>net8.0</TargetFramework>
     <OutputType>Exe</OutputType>
-    <AppDesignerFolder>Properties</AppDesignerFolder>
-    <RootNamespace>Markdig.Benchmarks</RootNamespace>
-    <AssemblyName>Markdig.Benchmarks</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <FileAlignment>512</FileAlignment>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFrameworkProfile />
-    <CopyNuGetImplementations>true</CopyNuGetImplementations>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <PlatformTarget>x86</PlatformTarget>
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <PlatformTarget>x86</PlatformTarget>
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <Prefer32Bit>true</Prefer32Bit>
+    <IsPackable>false</IsPackable>
+    <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="CommonMarkNew, Version=0.1.0.0, Culture=neutral, PublicKeyToken=001ef8810438905d, processorArchitecture=MSIL">
-      <HintPath>lib\CommonMarkNew.dll</HintPath>
-      <SpecificVersion>False</SpecificVersion>
-      <Aliases>newcmark</Aliases>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="Microsoft.Build" />
-    <Reference Include="Microsoft.Build.Framework" />
-    <Reference Include="Microsoft.Build.Utilities.v4.0" />
-    <Reference Include="MoonShine">
-      <HintPath>lib\MoonShine.dll</HintPath>
-    </Reference>
-    <Reference Include="MarkdownDeep">
-      <HintPath>lib\MarkdownDeep.dll</HintPath>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Management" />
-    <Reference Include="System.Xml.Linq" />
-    <Reference Include="System.Data.DataSetExtensions" />
-    <Reference Include="Microsoft.CSharp" />
-    <Reference Include="System.Data" />
-    <Reference Include="System.Net.Http" />
-    <Reference Include="System.Xml" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="CommonMarkLib.cs" />
-    <Compile Include="Program.cs" />
-    <Compile Include="Properties\AssemblyInfo.cs" />
-    <Compile Include="TestMatchPerf.cs" />
-    <Compile Include="TestStringPerf.cs" />
+    <None Remove="spec.md" />
   </ItemGroup>
   <ItemGroup>
     <Content Include="cmark.dll">
       <HintPath>cmark.dll</HintPath>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
-    <Content Include="libsundown.dll">
-      <HintPath>libsundown.dll</HintPath>
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </Content>
     <Content Include="spec.md">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
-    <None Include="app.config" />
-    <None Include="project.json" />
   </ItemGroup>
   <ItemGroup>
-    <Reference Include="Markdig">
-      <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\Markdig\Bin\$(Configuration)\net40\Markdig.dll</HintPath>
-    </Reference>
+    <PackageReference Include="BenchmarkDotNet" />
+    <PackageReference Include="BenchmarkDotNet.Diagnostics.Windows" />
+    <PackageReference Include="CommonMark.NET" />
+    <PackageReference Include="Markdown" />
+    <PackageReference Include="MarkdownSharp" />
+    <PackageReference Include="Microsoft.Diagnostics.Runtime" />
   </ItemGroup>
-  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
+  <ItemGroup>
+    <ProjectReference Include="..\Markdig\Markdig.csproj" />
+  </ItemGroup>
+</Project>

src/Markdig.Benchmarks/Markdig.Benchmarks.nuget.targets

@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="utf-8" standalone="no"?>
-<Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup Condition="'$(NuGetPackageRoot)' == ''">
-    <NuGetPackageRoot>$(UserProfile)\.nuget\packages\</NuGetPackageRoot>
-  </PropertyGroup>
-  <ImportGroup>
-    <Import Project="$(NuGetPackageRoot)\Microsoft.Diagnostics.Tracing.TraceEvent\1.0.41\build\Microsoft.Diagnostics.Tracing.TraceEvent.targets" Condition="Exists('$(NuGetPackageRoot)\Microsoft.Diagnostics.Tracing.TraceEvent\1.0.41\build\Microsoft.Diagnostics.Tracing.TraceEvent.targets')" />
-  </ImportGroup>
-</Project>

src/Markdig.Benchmarks/PipeTable/PipeTableBenchmark.cs

@@ -0,0 +1,81 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Diagnosers;
+using Markdig;
+
+namespace Testamina.Markdig.Benchmarks.PipeTable;
+
+/// <summary>
+/// Benchmark for pipe table parsing performance, especially for large tables.
+/// Tests the performance of PipeTableParser with varying table sizes.
+/// </summary>
+[MemoryDiagnoser]
+[GcServer(true)] // Use server GC to get more comprehensive GC stats
+public class PipeTableBenchmark
+{
+    private string _100Rows = null!;
+    private string _500Rows = null!;
+    private string _1000Rows = null!;
+    private string _1500Rows = null!;
+    private string _5000Rows = null!;
+    private string _10000Rows = null!;
+    private MarkdownPipeline _pipeline = null!;
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        // Pipeline with pipe tables enabled (part of advanced extensions)
+        _pipeline = new MarkdownPipelineBuilder()
+            .UseAdvancedExtensions()
+            .Build();
+
+        // Generate tables of various sizes
+        // Note: Before optimization, 5000+ rows hit depth limit due to nested tree structure.
+        // After optimization, these should work.
+        _100Rows = PipeTableGenerator.Generate(rows: 100, columns: 5);
+        _500Rows = PipeTableGenerator.Generate(rows: 500, columns: 5);
+        _1000Rows = PipeTableGenerator.Generate(rows: 1000, columns: 5);
+        _1500Rows = PipeTableGenerator.Generate(rows: 1500, columns: 5);
+        _5000Rows = PipeTableGenerator.Generate(rows: 5000, columns: 5);
+        _10000Rows = PipeTableGenerator.Generate(rows: 10000, columns: 5);
+    }
+
+    [Benchmark(Description = "PipeTable 100 rows x 5 cols")]
+    public string Parse100Rows()
+    {
+        return Markdown.ToHtml(_100Rows, _pipeline);
+    }
+
+    [Benchmark(Description = "PipeTable 500 rows x 5 cols")]
+    public string Parse500Rows()
+    {
+        return Markdown.ToHtml(_500Rows, _pipeline);
+    }
+
+    [Benchmark(Description = "PipeTable 1000 rows x 5 cols")]
+    public string Parse1000Rows()
+    {
+        return Markdown.ToHtml(_1000Rows, _pipeline);
+    }
+
+    [Benchmark(Description = "PipeTable 1500 rows x 5 cols")]
+    public string Parse1500Rows()
+    {
+        return Markdown.ToHtml(_1500Rows, _pipeline);
+    }
+
+    [Benchmark(Description = "PipeTable 5000 rows x 5 cols")]
+    public string Parse5000Rows()
+    {
+        return Markdown.ToHtml(_5000Rows, _pipeline);
+    }
+
+    [Benchmark(Description = "PipeTable 10000 rows x 5 cols")]
+    public string Parse10000Rows()
+    {
+        return Markdown.ToHtml(_10000Rows, _pipeline);
+    }
+}

src/Markdig.Benchmarks/PipeTable/PipeTableGenerator.cs

@@ -0,0 +1,61 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+using System.Text;
+
+namespace Testamina.Markdig.Benchmarks.PipeTable;
+
+/// <summary>
+/// Generates pipe table markdown content for benchmarking purposes.
+/// </summary>
+public static class PipeTableGenerator
+{
+    private const int DefaultCellWidth = 10;
+
+    /// <summary>
+    /// Generates a pipe table in markdown format.
+    /// </summary>
+    /// <param name="rows">Number of data rows (excluding header)</param>
+    /// <param name="columns">Number of columns</param>
+    /// <param name="cellWidth">Width of each cell content (default: 10)</param>
+    /// <returns>Pipe table markdown string</returns>
+    public static string Generate(int rows, int columns, int cellWidth = DefaultCellWidth)
+    {
+        var sb = new StringBuilder();
+
+        // Header row
+        sb.Append('|');
+        for (int col = 0; col < columns; col++)
+        {
+            sb.Append(' ');
+            sb.Append($"Header {col + 1}".PadRight(cellWidth));
+            sb.Append(" |");
+        }
+        sb.AppendLine();
+
+        // Separator row (with dashes)
+        sb.Append('|');
+        for (int col = 0; col < columns; col++)
+        {
+            sb.Append(new string('-', cellWidth + 2));
+            sb.Append('|');
+        }
+        sb.AppendLine();
+
+        // Data rows
+        for (int row = 0; row < rows; row++)
+        {
+            sb.Append('|');
+            for (int col = 0; col < columns; col++)
+            {
+                sb.Append(' ');
+                sb.Append($"R{row + 1}C{col + 1}".PadRight(cellWidth));
+                sb.Append(" |");
+            }
+            sb.AppendLine();
+        }
+
+        return sb.ToString();
+    }
+}

src/Markdig.Benchmarks/Program.cs

@@ -1,152 +1,86 @@
-// Copyright (c) Alexandre Mutel. All rights reserved.
+// Copyright (c) Alexandre Mutel. All rights reserved.
 // This file is licensed under the BSD-Clause 2 license. 
 // See the license.txt file in the project root for more information.
-extern alias newcmark;
-using System;
-using System.Diagnostics;
-using System.IO;
-using System.Text;
+
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Configs;
-using BenchmarkDotNet.Diagnostics;
-using BenchmarkDotNet.Diagnostics.Windows;
-using BenchmarkDotNet.Jobs;
 using BenchmarkDotNet.Running;
-using newcmark::CommonMark.Extension;
+
 using Markdig;
+using Testamina.Markdig.Benchmarks.PipeTable;
 
 
-namespace Testamina.Markdig.Benchmarks
+namespace Testamina.Markdig.Benchmarks;
+
+//[BenchmarkTask(platform: BenchmarkPlatform.X64, jitVersion: BenchmarkJitVersion.RyuJit, processCount: 1, warmupIterationCount: 2)]
+public class Program
 {
-    //[BenchmarkTask(platform: BenchmarkPlatform.X64, jitVersion: BenchmarkJitVersion.RyuJit, processCount: 1, warmupIterationCount: 2)]
-    public class Program
+    private string text;
+
+    public Program()
     {
-        private string text;
+        //text = File.ReadAllText("progit.md");
+        text = File.ReadAllText("spec.md");
+    }
 
-        public Program()
+    //[Benchmark(Description = "TestMarkdig", OperationsPerInvoke = 4096)]
+    [Benchmark(Description = "markdig")]
+    public void TestMarkdig()
+    {
+        //var reader = new StreamReader(File.Open("spec.md", FileMode.Open));
+        Markdown.ToHtml(text);
+        //File.WriteAllText("spec.html", writer.ToString());
+    }
+
+    [Benchmark(Description = "cmark")]
+    public void TestCommonMarkCpp()
+    {
+        //var reader = new StreamReader(File.Open("spec.md", FileMode.Open));
+        CommonMarkLib.ToHtml(text);
+        //File.WriteAllText("spec.html", writer.ToString());
+    }
+
+    [Benchmark(Description = "CommonMark.NET")]
+    public void TestCommonMarkNet()
+    {
+        ////var reader = new StreamReader(File.Open("spec.md", FileMode.Open));
+        // var reader = new StringReader(text);
+        //CommonMark.CommonMarkConverter.Parse(reader);
+        //CommonMark.CommonMarkConverter.Parse(reader);
+        //reader.Dispose();
+        //var writer = new StringWriter();
+        CommonMark.CommonMarkConverter.Convert(text);
+        //writer.Flush();
+        //writer.ToString();
+    }
+
+    [Benchmark(Description = "MarkdownSharp")]
+    public void TestMarkdownSharp()
+    {
+        new MarkdownSharp.Markdown().Transform(text);
+    }
+
+    static void Main(string[] args)
+    {
+        var config = ManualConfig.Create(DefaultConfig.Instance);
+        //var gcDiagnoser = new MemoryDiagnoser();
+        //config.Add(new Job { Mode = Mode.SingleRun, LaunchCount = 2, WarmupCount = 2, IterationTime = 1024, TargetCount = 10 });
+        //config.Add(new Job { Mode = Mode.Throughput, LaunchCount = 2, WarmupCount = 2, TargetCount = 10 });
+        //config.Add(gcDiagnoser);
+
+        //var  config = DefaultConfig.Instance;
+
+        // Run specific benchmarks based on command line arguments
+        if (args.Length > 0 && args[0] == "--pipetable")
         {
-            //text = File.ReadAllText("progit.md");
-            text = File.ReadAllText("spec.md");
+            BenchmarkRunner.Run<PipeTableBenchmark>(config);
         }
-
-        //[Benchmark(Description = "TestMarkdig", OperationsPerInvoke = 4096)]
-        [Benchmark]
-        public void TestMarkdig()
+        else
         {
-            //var reader = new StreamReader(File.Open("spec.md", FileMode.Open));
-            Markdown.ToHtml(text);
-            //File.WriteAllText("spec.html", writer.ToString());
-        }
-
-        [Benchmark]
-        public void TestCommonMarkCpp()
-        {
-            //var reader = new StreamReader(File.Open("spec.md", FileMode.Open));
-            CommonMarkLib.ToHtml(text);
-            //File.WriteAllText("spec.html", writer.ToString());
-        }
-
-        [Benchmark]
-        public void TestCommonMarkNet()
-        {
-            ////var reader = new StreamReader(File.Open("spec.md", FileMode.Open));
-            // var reader = new StringReader(text);
-            //CommonMark.CommonMarkConverter.Parse(reader);
-            //CommonMark.CommonMarkConverter.Parse(reader);
-            //reader.Dispose();
-            //var writer = new StringWriter();
-            global::CommonMark.CommonMarkConverter.Convert(text);
-            //writer.Flush();
-            //writer.ToString();
-        }
-
-        [Benchmark]
-        public void TestCommonMarkNetNew()
-        {
-            ////var reader = new StreamReader(File.Open("spec.md", FileMode.Open));
-            // var reader = new StringReader(text);
-            //CommonMark.CommonMarkConverter.Parse(reader);
-            //CommonMark.CommonMarkConverter.Parse(reader);
-            //reader.Dispose();
-            //var writer = new StringWriter();
-            newcmark::CommonMark.CommonMarkConverter.Convert(text);
-            //writer.Flush();
-            //writer.ToString();
-        }
-
-        [Benchmark]
-        public void TestMarkdownDeep()
-        {
-            new MarkdownDeep.Markdown().Transform(text);
-        }
-
-        [Benchmark]
-        public void TestMarkdownSharp()
-        {
-            new MarkdownSharp.Markdown().Transform(text);
-        }
-
-        [Benchmark]
-        public void TestMoonshine()
-        {
-            Sundown.MoonShine.Markdownify(text);
-        }
-
-        static void Main(string[] args)
-        {
-            bool markdig = args.Length == 0;
-            bool simpleBench = false;
-
-            if (simpleBench)
-            {
-                var clock = Stopwatch.StartNew();
-                var program = new Program();
-
-                GC.Collect(2, GCCollectionMode.Forced, true);
-
-                var gc0 = GC.CollectionCount(0);
-                var gc1 = GC.CollectionCount(1);
-                var gc2 = GC.CollectionCount(2);
-
-                const int count = 12*64;
-                for (int i = 0; i < count; i++)
-                {
-                    if (markdig)
-                    {
-                        program.TestMarkdig();
-                    }
-                    else
-                    {
-                        program.TestCommonMarkNetNew();
-                    }
-                }
-                clock.Stop();
-                Console.WriteLine((markdig ? "MarkDig" : "CommonMark") +  $" => time: {(double)clock.ElapsedMilliseconds/count}ms (total {clock.ElapsedMilliseconds}ms)");
-                DumpGC(gc0, gc1, gc2);
-            }
-            else
-            {
-                //new TestMatchPerf().TestMatch();
-
-                var config = ManualConfig.Create(DefaultConfig.Instance);
-                //var gcDiagnoser = new MemoryDiagnoser();
-                //config.Add(new Job { Mode = Mode.SingleRun, LaunchCount = 2, WarmupCount = 2, IterationTime = 1024, TargetCount = 10 });
-                config.Add(new Job { Mode = Mode.Throughput, LaunchCount = 2, WarmupCount = 2, TargetCount = 10 });
-                //config.Add(gcDiagnoser);
-
-                //var  config = DefaultConfig.Instance;
-                BenchmarkRunner.Run<Program>(config);
-                //BenchmarkRunner.Run<TestDictionary>(config);
-                //BenchmarkRunner.Run<TestMatchPerf>();
-                //BenchmarkRunner.Run<TestStringPerf>();
-            }
-        }
-
-        private static void DumpGC(int gc0, int gc1, int gc2)
-        {
-            Console.WriteLine($"gc0: {GC.CollectionCount(0)-gc0}");
-            Console.WriteLine($"gc1: {GC.CollectionCount(1)-gc1}");
-            Console.WriteLine($"gc2: {GC.CollectionCount(2)-gc2}");
+            BenchmarkRunner.Run<Program>(config);
         }
+        //BenchmarkRunner.Run<TestDictionary>(config);
+        //BenchmarkRunner.Run<TestMatchPerf>();
+        //BenchmarkRunner.Run<TestStringPerf>();
     }
 }

src/Markdig.Benchmarks/Properties/AssemblyInfo.cs

@@ -1,36 +0,0 @@
-using System.Reflection;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
-
-// General Information about an assembly is controlled through the following 
-// set of attributes. Change these attribute values to modify the information
-// associated with an assembly.
-[assembly: AssemblyTitle("Testamina.Markdig.Benchmarks")]
-[assembly: AssemblyDescription("")]
-[assembly: AssemblyConfiguration("")]
-[assembly: AssemblyCompany("")]
-[assembly: AssemblyProduct("Testamina.Markdig.Benchmarks")]
-[assembly: AssemblyCopyright("Copyright ©  2016")]
-[assembly: AssemblyTrademark("")]
-[assembly: AssemblyCulture("")]
-
-// Setting ComVisible to false makes the types in this assembly not visible 
-// to COM components.  If you need to access a type in this assembly from 
-// COM, set the ComVisible attribute to true on that type.
-[assembly: ComVisible(false)]
-
-// The following GUID is for the ID of the typelib if this project is exposed to COM
-[assembly: Guid("6a19f040-bc7c-4283-873a-177b5324f1ed")]
-
-// Version information for an assembly consists of the following four values:
-//
-//      Major Version
-//      Minor Version 
-//      Build Number
-//      Revision
-//
-// You can specify all the values or you can default the Build and Revision Numbers 
-// by using the '*' as shown below:
-// [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.0.0.0")]
-[assembly: AssemblyFileVersion("1.0.0.0")]

src/Markdig.Benchmarks/Properties/launchSettings.json

@@ -1,8 +0,0 @@
-{
-  "profiles": {
-    "CLASSIC": {
-      "executablePath": "Testamina.Markdig.Benchmarks.dll",
-      "workingDirectory": "..\\..\\artifacts\\bin\\Testamina.Markdig.Benchmarks\\Debug\\net45"
-    }
-  }
-}

src/Markdig.Benchmarks/TestMatchPerf.cs

@@ -1,85 +1,80 @@
-// Copyright (c) Alexandre Mutel. All rights reserved.
+// Copyright (c) Alexandre Mutel. All rights reserved.
 // This file is licensed under the BSD-Clause 2 license. 
 // See the license.txt file in the project root for more information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
-using BenchmarkDotNet.Attributes;
-using Markdig.Helpers;
 
-namespace Testamina.Markdig.Benchmarks
+namespace Testamina.Markdig.Benchmarks;
+
+public class TextRegexHelper
 {
-    public class TextRegexHelper
+    private readonly Dictionary<string, string> replacers;
+    private readonly Regex regex;
+
+    public TextRegexHelper(Dictionary<string, string> replacers)
     {
-        private readonly Dictionary<string, string> replacers;
-        private readonly Regex regex;
+        this.replacers = replacers;
+        var builder = new StringBuilder();
 
-        public TextRegexHelper(Dictionary<string, string> replacers)
+        // (?<1>:value:?)|(?<1>:noo:?)
+        foreach (var replace in replacers)
         {
-            this.replacers = replacers;
-            var builder = new StringBuilder();
-
-            // (?<1>:value:?)|(?<1>:noo:?)
-            foreach (var replace in replacers)
+            var matchStr = Regex.Escape(replace.Key);
+            if (builder.Length > 0)
             {
-                var matchStr = Regex.Escape(replace.Key);
-                if (builder.Length > 0)
-                {
-                    builder.Append('|');
-                }
-                builder.Append("(?<1>").Append(matchStr).Append("?)");
+                builder.Append('|');
             }
-
-            regex = new Regex(builder.ToString());
+            builder.Append("(?<1>").Append(matchStr).Append("?)");
         }
 
-        public bool TryMatch(string text, int offset, out string matchText, out string replaceText)
-        {
-            replaceText = null;
-            matchText = null;
-            var result = regex.Match(text, offset);
-            if (!result.Success)
-            {
-                return false;
-            }
-
-            matchText = result.Groups[1].Value;
-            replaceText = replacers[matchText];
-            return true;
-        }
+        regex = new Regex(builder.ToString());
     }
 
-
-    public class TestMatchPerf
+    public bool TryMatch(string text, int offset, out string matchText, out string replaceText)
     {
-        private readonly TextMatchHelper matcher;
-
-        public TestMatchPerf()
+        replaceText = null;
+        matchText = null;
+        var result = regex.Match(text, offset);
+        if (!result.Success)
         {
-            var replacers = new Dictionary<string, string>();
-            for (int i = 0; i < 1000; i++)
-            {
-                replacers.Add($":z{i}:", i.ToString());
-            }
-            replacers.Add(":abc:", "yes");
-
-            matcher = new TextMatchHelper(new HashSet<string>(replacers.Keys));
+            return false;
         }
 
-        [Benchmark]
-        public void TestMatch()
-        {
+        matchText = result.Groups[1].Value;
+        replaceText = replacers[matchText];
+        return true;
+    }
+}
 
-            for (int i = 0; i < 1000; i++)
-            {
-                string matchText;
-                //var text = ":z150: this is a long string";
-                var text = ":z1:";
-                matcher.TryMatch(text, 0, text.Length, out matchText);
-            }
+/*
+public class TestMatchPerf
+{
+    private readonly TextMatchHelper matcher;
+
+    public TestMatchPerf()
+    {
+        var replacers = new Dictionary<string, string>();
+        for (int i = 0; i < 1000; i++)
+        {
+            replacers.Add($":z{i}:", i.ToString());
+        }
+        replacers.Add(":abc:", "yes");
+
+        matcher = new TextMatchHelper(new HashSet<string>(replacers.Keys));
+    }
+
+    [Benchmark]
+    public void TestMatch()
+    {
+
+        for (int i = 0; i < 1000; i++)
+        {
+            string matchText;
+            //var text = ":z150: this is a long string";
+            var text = ":z1:";
+            matcher.TryMatch(text, 0, text.Length, out matchText);
         }
     }
-}
+}
+*/

src/Markdig.Benchmarks/TestStringPerf.cs

@@ -1,58 +1,57 @@
-using System.IO;
 using BenchmarkDotNet.Attributes;
+
 using Markdig.Renderers;
 
-namespace Testamina.Markdig.Benchmarks
+namespace Testamina.Markdig.Benchmarks;
+
+public class TestStringPerf
 {
-    public class TestStringPerf
+    private string text;
+
+    public TestStringPerf()
     {
-        private string text;
-
-        public TestStringPerf()
-        {
-            text = new string('a', 1000);
-        }
-
-        [Benchmark]
-        public void TestIndexOfAny()
-        {
-            var writer = new HtmlRenderer(new StringWriter());
-            for (int i = 0; i < 100; i++)
-            {
-                writer.WriteEscape(text, 0, text.Length);
-                writer.WriteEscape(text, 0, text.Length);
-                writer.WriteEscape(text, 0, text.Length);
-                writer.WriteEscape(text, 0, text.Length);
-                writer.WriteEscape(text, 0, text.Length);
-
-                writer.WriteEscape(text, 0, text.Length);
-                writer.WriteEscape(text, 0, text.Length);
-                writer.WriteEscape(text, 0, text.Length);
-                writer.WriteEscape(text, 0, text.Length);
-                writer.WriteEscape(text, 0, text.Length);
-            }
-        }
-
-
-        //[Benchmark]
-        //public void TestCustomIndexOfAny()
-        //{
-        //    var writer = new HtmlRenderer(new StringWriter());
-        //    for (int i = 0; i < 100; i++)
-        //    {
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //        writer.WriteEscapeOptimized(text, 0, text.Length);
-        //    }
-        //}
-
+        text = new string('a', 1000);
     }
+
+    [Benchmark]
+    public void TestIndexOfAny()
+    {
+        var writer = new HtmlRenderer(new StringWriter());
+        for (int i = 0; i < 100; i++)
+        {
+            writer.WriteEscape(text, 0, text.Length);
+            writer.WriteEscape(text, 0, text.Length);
+            writer.WriteEscape(text, 0, text.Length);
+            writer.WriteEscape(text, 0, text.Length);
+            writer.WriteEscape(text, 0, text.Length);
+
+            writer.WriteEscape(text, 0, text.Length);
+            writer.WriteEscape(text, 0, text.Length);
+            writer.WriteEscape(text, 0, text.Length);
+            writer.WriteEscape(text, 0, text.Length);
+            writer.WriteEscape(text, 0, text.Length);
+        }
+    }
+
+
+    //[Benchmark]
+    //public void TestCustomIndexOfAny()
+    //{
+    //    var writer = new HtmlRenderer(new StringWriter());
+    //    for (int i = 0; i < 100; i++)
+    //    {
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //        writer.WriteEscapeOptimized(text, 0, text.Length);
+    //    }
+    //}
+
 }

src/Markdig.Benchmarks/app.config

@@ -1,3 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<configuration>
-<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/></startup></configuration>

src/Markdig.Benchmarks/project.json

@@ -1,29 +0,0 @@
-{
-  "runtimes": {
-    "win-x86": {},
-    "win-x64": {}
-  },
-  "frameworks": {
-    "net451": {
-      "compilationOptions": {
-        "define": [
-          "CLASSIC"
-        ]
-      },
-      "frameworkAssemblies": {
-        "Microsoft.Build": "4.0.0.0",
-        "Microsoft.Build.Framework": "4.0.0.0",
-        "Microsoft.Build.Utilities.v4.0": "4.0.0.0",
-        "System.Management": "4.0.0.0"
-      }
-    }
-  },
-  "dependencies": {
-    "BenchmarkDotNet": "0.9.6",
-    "BenchmarkDotNet.Diagnostics.Windows": "0.9.6",
-    "CommonMark.NET": "0.11.0",
-    "MarkdownSharp": "1.13.0.0",
-    "Microsoft.Diagnostics.Runtime": "0.8.31-beta",
-    "Microsoft.Diagnostics.Tracing.TraceEvent": "1.0.41.0"
-  }
-}

src/Markdig.Benchmarks/spec.md

@@ -5397,7 +5397,7 @@ foo
 ## Entity and numeric character references
 
 All valid HTML entity references and numeric character
-references, except those occuring in code blocks and code spans,
+references, except those occurring in code blocks and code spans,
 are recognized as such and treated as equivalent to the
 corresponding Unicode characters.  Conforming CommonMark parsers
 need not store information about whether a particular character

src/Markdig.Fuzzing/.gitignore

@@ -0,0 +1,4 @@
+corpus
+libfuzzer-dotnet-windows.exe
+crash-*
+timeout-*

src/Markdig.Fuzzing/Markdig.Fuzzing.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="SharpFuzz" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Markdig\Markdig.csproj" />
+  </ItemGroup>
+
+</Project>

src/Markdig.Fuzzing/Program.cs

@@ -0,0 +1,71 @@
+using Markdig;
+using Markdig.Renderers.Roundtrip;
+using Markdig.Syntax;
+using SharpFuzz;
+using System.Diagnostics;
+using System.Text;
+
+ReadOnlySpanAction fuzzTarget = ParseRenderFuzzer.FuzzTarget;
+
+if (args.Length > 0)
+{
+    // Run the target on existing inputs
+    string[] files = Directory.Exists(args[0])
+        ? Directory.GetFiles(args[0])
+        : [args[0]];
+
+    Debugger.Launch();
+
+    foreach (string inputFile in files)
+    {
+        fuzzTarget(File.ReadAllBytes(inputFile));
+    }
+}
+else
+{
+    Fuzzer.LibFuzzer.Run(fuzzTarget);
+}
+
+sealed class ParseRenderFuzzer
+{
+    private static readonly MarkdownPipeline s_advancedPipeline = new MarkdownPipelineBuilder()
+        .UseAdvancedExtensions()
+        .Build();
+
+    private static readonly ResettableRoundtripRenderer _roundtripRenderer = new();
+
+    public static void FuzzTarget(ReadOnlySpan<byte> bytes)
+    {
+        string text = Encoding.UTF8.GetString(bytes);
+
+        try
+        {
+            MarkdownDocument document = Markdown.Parse(text);
+            _ = document.ToHtml();
+
+            document = Markdown.Parse(text, s_advancedPipeline);
+            _ = document.ToHtml(s_advancedPipeline);
+
+            document = Markdown.Parse(text, trackTrivia: true);
+            _ = document.ToHtml();
+            _roundtripRenderer.Reset();
+            _roundtripRenderer.Render(document);
+
+            _ = Markdown.Normalize(text);
+            _ = Markdown.ToPlainText(text);
+        }
+        catch (Exception ex) when (IsIgnorableException(ex)) { }
+    }
+
+    private static bool IsIgnorableException(Exception exception)
+    {
+        return exception.Message.Contains("Markdown elements in the input are too deeply nested", StringComparison.Ordinal);
+    }
+
+    private sealed class ResettableRoundtripRenderer : RoundtripRenderer
+    {
+        public ResettableRoundtripRenderer() : base(new StringWriter(new StringBuilder(1024 * 1024))) { }
+
+        public new void Reset() => base.Reset();
+    }
+}

src/Markdig.Fuzzing/run-fuzzer.ps1

@@ -0,0 +1,86 @@
+param (
+    [string]$configuration = $null
+)
+
+Set-StrictMode -Version Latest
+
+$libFuzzer = "libfuzzer-dotnet-windows.exe"
+$outputDir = "bin"
+
+function Get-LibFuzzer {
+    param (
+        [string]$Path
+    )
+
+    $libFuzzerUrl = "https://github.com/Metalnem/libfuzzer-dotnet/releases/download/v2025.05.02.0904/libfuzzer-dotnet-windows.exe"
+    $expectedHash = "17af5b3f6ff4d2c57b44b9a35c13051b570eb66f0557d00015df3832709050bf"
+
+    Write-Output "Downloading libFuzzer from $libFuzzerUrl..."
+
+    try {
+        $tempFile = "$Path.tmp"
+        Invoke-WebRequest -Uri $libFuzzerUrl -OutFile $tempFile -UseBasicParsing
+
+        $downloadedHash = (Get-FileHash -Path $tempFile -Algorithm SHA256).Hash
+
+        if ($downloadedHash -eq $ExpectedHash) {
+            Move-Item -Path $tempFile -Destination $Path -Force
+            Write-Output "libFuzzer downloaded successfully to $Path"
+        }
+        else {
+            Write-Error "Hash validation failed."
+            Remove-Item -Path $tempFile -Force -ErrorAction SilentlyContinue
+            exit 1
+        }
+    }
+    catch {
+        Write-Error "Failed to download libFuzzer: $($_.Exception.Message)"
+        Remove-Item -Path $tempFile -Force -ErrorAction SilentlyContinue
+        exit 1
+    }
+}
+
+# Check if libFuzzer exists, download if not
+if (-not (Test-Path $libFuzzer)) {
+    Get-LibFuzzer -Path $libFuzzer
+}
+
+$toolListOutput = dotnet tool list --global sharpFuzz.CommandLine 2>$null
+if (-not ($toolListOutput -match "sharpfuzz")) {
+    Write-Output "Installing sharpfuzz CLI"
+    dotnet tool install --global sharpFuzz.CommandLine
+}
+
+if (Test-Path $outputDir) {
+    Remove-Item -Recurse -Force $outputDir
+}
+
+if ($configuration -eq $null) {
+    $configuration = "Debug"
+}
+
+dotnet publish -c $configuration -o $outputDir
+
+$project = Join-Path $outputDir "Markdig.Fuzzing.dll"
+
+$fuzzingTarget = Join-Path $outputDir "Markdig.dll"
+
+Write-Output "Instrumenting $fuzzingTarget"
+& sharpfuzz $fuzzingTarget
+
+if ($LastExitCode -ne 0) {
+    Write-Error "An error occurred while instrumenting $fuzzingTarget"
+    exit 1
+}
+
+New-Item -ItemType Directory -Force -Path corpus | Out-Null
+
+$libFuzzerArgs = @("--target_path=dotnet", "--target_arg=$project", "-timeout=10", "corpus")
+
+# Add any additional arguments passed to the script
+if ($args) {
+    $libFuzzerArgs += $args
+}
+
+Write-Output "Starting libFuzzer with arguments: $libFuzzerArgs"
+& ./$libFuzzer @libFuzzerArgs

src/Markdig.Signed/Markdig.Signed.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <PackageId>Markdig.Signed</PackageId>
+    <AssemblyOriginatorKeyFile>key.snk</AssemblyOriginatorKeyFile>
+    <SignAssembly>true</SignAssembly>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="..\Markdig\**\*.cs" Exclude="..\Markdig\obj\**;..\Markdig\bin\**">
+      <Link>%(RecursiveDir)%(Filename)%(Extension)</Link>
+    </Compile>
+  </ItemGroup>
+  <Import Project="..\Markdig\Markdig.targets" />
+</Project>

src/Markdig.Tests/App.config

@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<configuration>
-    <startup> 
-        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/>
-    </startup>
-</configuration>

src/Markdig.Tests/GlobalUsings.cs

@@ -0,0 +1,5 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+global using Assert = NUnit.Framework.Legacy.ClassicAssert;

src/Markdig.Tests/Markdig.Tests.csproj

@@ -1,107 +1,56 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+<Project Sdk="Microsoft.NET.Sdk">
+
   <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <ProjectGuid>{A0C5CB5F-5568-40AB-B945-D6D2664D51B0}</ProjectGuid>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
     <OutputType>Exe</OutputType>
-    <AppDesignerFolder>Properties</AppDesignerFolder>
-    <RootNamespace>Markdig.Tests</RootNamespace>
-    <AssemblyName>Markdig.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <FileAlignment>512</FileAlignment>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <CopyNuGetImplementations>true</CopyNuGetImplementations>
-    <TargetFrameworkProfile />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-  </PropertyGroup>
-  <PropertyGroup>
-    <StartupObject />
+    <IsPackable>false</IsPackable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>13.0</LangVersion>
+    <StartupObject>Markdig.Tests.Program</StartupObject>
+    <SpecExecutable>$(MSBuildProjectDirectory)\..\SpecFileGen\bin\$(Configuration)\$(TargetFramework)\SpecFileGen.dll</SpecExecutable>
+    <SpecTimestamp>$(MSBuildProjectDirectory)\..\SpecFileGen\bin\$(Configuration)\$(TargetFramework)\SpecFileGen.timestamp</SpecTimestamp>
+    <NoWarn>$(NoWarn);NETSDK1138</NoWarn>
   </PropertyGroup>
+
   <ItemGroup>
-    <Reference Include="Markdig">
-      <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\Markdig\Bin\$(Configuration)\net40\Markdig.dll</HintPath>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Xml.Linq" />
-    <Reference Include="System.Data.DataSetExtensions" />
-    <Reference Include="Microsoft.CSharp" />
-    <Reference Include="System.Data" />
-    <Reference Include="System.Net.Http" />
-    <Reference Include="System.Xml" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="NUnit" />
+    <PackageReference Include="NUnit3TestAdapter" />
   </ItemGroup>
+
   <ItemGroup>
-    <Compile Include="Program.cs" />
-    <Compile Include="Properties\AssemblyInfo.cs" />
-    <Compile Include="Specs\Specs.cs">
-      <AutoGen>True</AutoGen>
-      <DesignTime>True</DesignTime>
-      <DependentUpon>Specs.tt</DependentUpon>
-    </Compile>
-    <Compile Include="TestHtmlHelper.cs" />
-    <Compile Include="TestLinkHelper.cs" />
-    <Compile Include="TestStringSliceList.cs" />
-    <Compile Include="TestPlayParser.cs" />
-    <Compile Include="TextAssert.cs" />
-    <Compile Include="TestParser.cs" />
+    <ProjectReference Include="..\Markdig\Markdig.csproj" />
+    <ProjectReference Include="..\SpecFileGen\SpecFileGen.csproj" />
   </ItemGroup>
+
   <ItemGroup>
-    <None Include="App.config" />
-    <None Include="project.json" />
-    <None Include="Specs\AutoIdentifierSpecs.md" />
-    <None Include="Specs\AbbreviationSpecs.md" />
-    <None Include="Specs\FigureFooterAndCiteSpecs.md" />
-    <None Include="Specs\ListExtraSpecs.md" />
-    <None Include="Specs\GenericAttributesSpecs.md" />
-    <None Include="Specs\CustomContainerSpecs.md" />
-    <None Include="Specs\DefinitionListSpecs.md" />
-    <None Include="Specs\EmojiSpecs.md" />
-    <None Include="Specs\FootnotesSpecs.md" />
-    <None Include="Specs\GridTableSpecs.md" />
-    <None Include="Specs\HardlineBreakSpecs.md" />
-    <None Include="Specs\BootstrapSpecs.md" />
-    <None Include="Specs\SmartyPantsSpecs.md" />
-    <None Include="Specs\MediaSpecs.md" />
-    <None Include="Specs\MathSpecs.md" />
-    <None Include="Specs\PipeTableSpecs.md" />
-    <None Include="Specs\EmphasisExtraSpecs.md" />
+    <Using Include="NUnit.Framework" />
   </ItemGroup>
+
   <ItemGroup>
-    <Content Include="Specs\Specs.tt">
-      <Generator>TextTemplatingFileGenerator</Generator>
-      <LastGenOutput>Specs.cs</LastGenOutput>
-    </Content>
+    <ItemSpecExecutable Include="$(SpecExecutable)" />
+    <InputSpecFiles Include="Specs\*.md" />
+    <InputSpecFiles Include="NormalizeSpecs\*.md" />
+    <InputSpecFiles Include="PlainTextSpecs\*.md" />
+    <InputSpecFiles Include="RoundtripSpecs\*.md" />
+    <InputSpecFiles Remove="Specs\readme.md" />
+    <!-- Allow Visual Studio up-to-date check to verify that nothing has changed - https://github.com/dotnet/project-system/blob/main/docs/up-to-date-check.md -->
+    <UpToDateCheckInput Include="@(InputSpecFiles)" />
+    <OutputSpecFiles Include="@(InputSpecFiles-&gt;'%(RelativeDir)%(Filename).generated.cs')" />
   </ItemGroup>
-  <ItemGroup>
-    <Service Include="{508349B6-6B84-4DF5-91F0-309BEEBAD82D}" />
-  </ItemGroup>
-  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
+
+  <Target Name="GeneratedSpecsFile" BeforeTargets="BeforeCompile;CoreCompile" Inputs="@(ItemSpecExecutable);@(InputSpecFiles)" Outputs="@(ItemSpecExecutable-&gt;'%(RelativeDir)%(Filename).timestamp');@(InputSpecFiles-&gt;'%(RelativeDir)%(Filename).generated.cs')">
+    <Message Importance="high" Text="Regenerating Specs Files" />
+    <Exec Command="dotnet $(SpecExecutable)" />
+    <WriteLinesToFile File="$(SpecTimestamp)" Lines="$([System.DateTime]::Now)" />
+    <ItemGroup>
+      <FileWrites Include="$(SpecTimestamp)" />
+      <_GeneratedSpecsFile Include="Specs\*.generated.cs" />
+      <_GeneratedSpecsFile Include="NormalizeSpecs\*.generated.cs" />
+      <_GeneratedSpecsFile Include="PlainTextSpecs\*.generated.cs" />
+      <_GeneratedSpecsFile Include="RoundtripSpecs\*.generated.cs" />
+      <_GeneratedSpecsFile Remove="@(Compile)" />
+      <Compile Include="@(_GeneratedSpecsFile)" />
+    </ItemGroup>
   </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
 </Project>

src/Markdig.Tests/MiscTests.cs

@@ -0,0 +1,412 @@
+using System.Text.RegularExpressions;
+
+using Markdig.Extensions.AutoLinks;
+using Markdig.Extensions.Tables;
+using Markdig.Syntax;
+using NUnit.Framework;
+
+namespace Markdig.Tests;
+
+public class MiscTests
+{
+    [Test]
+    public void LinkWithInvalidNonAsciiDomainNameIsIgnored()
+    {
+        // Url from https://github.com/lunet-io/markdig/issues/438
+        _ = Markdown.ToHtml("[minulém díle](http://V%20minulém%20díle%20jsme%20nainstalovali%20SQL%20Server,%20který%20je%20nutný%20pro%20běh%20Configuration%20Manageru.%20Dnes%20nás%20čeká%20instalace%20WSUS,%20což%20je%20produkt,%20jež%20je%20možné%20používat%20i%20jako%20samostatnou%20funkci%20ve%20Windows%20Serveru,%20který%20se%20stará%20o%20stažení%20a%20instalaci%20aktualizací%20z%20Microsoft%20Update%20na%20klientské%20počítače.%20Stejně%20jako%20v%20předchozích%20dílech,%20tak%20i%20v%20tomto%20si%20ukážeme%20obě%20varianty%20instalace%20–%20a%20to%20jak%20instalaci%20z%20PowerShellu,%20tak%20instalaci%20pomocí%20GUI.) ");
+
+        // Valid IDN
+        TestParser.TestSpec("[foo](http://ünicode.com)", "<p><a href=\"http://xn--nicode-2ya.com\">foo</a></p>");
+        TestParser.TestSpec("[foo](http://ünicode.ünicode.com)", "<p><a href=\"http://xn--nicode-2ya.xn--nicode-2ya.com\">foo</a></p>");
+
+        // Invalid IDN
+        TestParser.TestSpec("[foo](http://ünicode..com)", "<p><a href=\"http://%C3%BCnicode..com\">foo</a></p>");
+    }
+
+    [TestCase("link [foo [bar]]")] // https://spec.commonmark.org/0.29/#example-508
+    [TestCase("link [foo][bar]")]
+    [TestCase("link [][foo][bar][]")]
+    [TestCase("link [][foo][bar][[]]")]
+    [TestCase("link [foo] [bar]")]
+    [TestCase("link [[foo] [] [bar] [[abc]def]]")]
+    [TestCase("[]")]
+    [TestCase("[ ]")]
+    [TestCase("[bar][]")]
+    [TestCase("[bar][ foo]")]
+    [TestCase("[bar][foo ][]")]
+    [TestCase("[bar][fo[ ]o ][][]")]
+    [TestCase("[a]b[c[d[e]f]g]h")]
+    [TestCase("a[b[c[d]e]f[g]h]i foo [j]k[l[m]n]o")]
+    [TestCase("a[b[c[d]e]f[g]h]i[] [][foo][bar][] foo [j]k[l[m]n]o")]
+    [TestCase("a[b[c[d]e]f[g]h]i foo [j]k[l[m]n]o[][]")]
+    public void LinkTextMayContainBalancedBrackets(string linkText)
+    {
+        string markdown = $"[{linkText}](/uri)";
+        string expected = $@"<p><a href=""/uri"">{linkText}</a></p>";
+
+        TestParser.TestSpec(markdown, expected);
+
+        // Make the link text unbalanced
+        foreach (var bracketIndex in linkText
+            .Select((c, i) => new Tuple<char, int>(c, i))
+            .Where(t => t.Item1 == '[' || t.Item1 == ']')
+            .Select(t => t.Item2))
+        {
+            string brokenLinkText = linkText.Remove(bracketIndex, 1);
+
+            markdown = $"[{brokenLinkText}](/uri)";
+            expected = $@"<p><a href=""/uri"">{brokenLinkText}</a></p>";
+
+            string actual = Markdown.ToHtml(markdown);
+            Assert.AreNotEqual(expected, actual);
+        }
+    }
+
+    [Theory]
+    [TestCase('[', 9 * 1024, true, false)]
+    [TestCase('[', 11 * 1024, true, true)]
+    [TestCase('[', 100, false, false)]
+    [TestCase('[', 150, false, true)]
+    [TestCase('>', 100, true, false)]
+    [TestCase('>', 150, true, true)]
+    public void GuardsAgainstHighlyNestedNodes(char c, int count, bool parseOnly, bool shouldThrow)
+    {
+        var markdown = new string(c, count);
+        TestDelegate test = parseOnly ? () => Markdown.Parse(markdown) : () => Markdown.ToHtml(markdown);
+
+        if (shouldThrow)
+        {
+            Exception e = Assert.Throws<ArgumentException>(test);
+            Assert.True(e.Message.Contains("depth limit"));
+        }
+        else
+        {
+            test();
+        }
+    }
+
+    [Test]
+    public void IsIssue356Corrected()
+    {
+        string input = @"https://foo.bar/path/\#m4mv5W0GYKZpGvfA.97";
+        string expected = @"<p><a href=""https://foo.bar/path/%5C#m4mv5W0GYKZpGvfA.97"">https://foo.bar/path/\#m4mv5W0GYKZpGvfA.97</a></p>";
+
+        TestParser.TestSpec($"<{input}>", expected);
+        TestParser.TestSpec(input, expected, "autolinks|advanced");
+    }
+
+    [Test]
+    public void IsIssue365Corrected()
+    {
+        // The scheme must be escaped too...
+        string input = "![image](\"onclick=\"alert&amp;#40;'click'&amp;#41;\"://)";
+        string expected = "<p><img src=\"%22onclick=%22alert&amp;#40;%27click%27&amp;#41;%22://\" alt=\"image\" /></p>";
+
+        TestParser.TestSpec(input, expected);
+    }
+
+    [Test]
+    public void TestAltTextIsCorrectlyEscaped()
+    {
+        TestParser.TestSpec(
+            @"![This is image alt text with quotation ' and double quotation ""hello"" world](girl.png)",
+            @"<p><img src=""girl.png"" alt=""This is image alt text with quotation ' and double quotation &quot;hello&quot; world"" /></p>");
+    }
+
+    [Test]
+    public void TestChangelogPRLinksMatchDescription()
+    {
+        string solutionFolder = Path.GetFullPath(Path.Combine(TestParser.TestsDirectory, "../.."));
+        string changelogPath = Path.Combine(solutionFolder, "changelog.md");
+        string changelog = File.ReadAllText(changelogPath);
+        var matches = Regex.Matches(changelog, @"\(\[\(PR #(\d+)\)\]\(.*?pull\/(\d+)\)\)");
+        Assert.Greater(matches.Count, 0);
+        foreach (Match match in matches)
+        {
+            Assert.True(int.TryParse(match.Groups[1].Value, out int textNr));
+            Assert.True(int.TryParse(match.Groups[2].Value, out int linkNr));
+            Assert.AreEqual(textNr, linkNr);
+        }
+    }
+
+    [Test]
+    public void TestFixHang()
+    {
+        var input = File.ReadAllText(Path.Combine(TestParser.TestsDirectory, "hang.md"));
+        _ = Markdown.ToHtml(input);
+    }
+
+    [Test]
+    public void TestInvalidHtmlEntity()
+    {
+        var input = "9&ddr;&*&ddr;&de<64><65>__";
+        TestParser.TestSpec(input, "<p>9&amp;ddr;&amp;*&amp;ddr;&amp;de<64><65>__</p>");
+    }
+
+    [Test]
+    public void TestInvalidCharacterHandling()
+    {
+        var input = File.ReadAllText(Path.Combine(TestParser.TestsDirectory, "ArgumentOutOfRangeException.md"));
+        _ = Markdown.ToHtml(input);
+    }
+
+    [Test]
+    public void TestInvalidCodeEscape()
+    {
+        var input = "```**Header**	";
+        _ = Markdown.ToHtml(input);
+    }
+
+    [Test]
+    public void TestEmphasisAndHtmlEntity()
+    {
+        var markdownText = "*Unlimited-Fun&#174;*&#174;";
+        TestParser.TestSpec(markdownText, "<p><em>Unlimited-Fun®</em>®</p>");
+    }
+
+    [Test]
+    public void TestThematicInsideCodeBlockInsideList()
+    {
+        var input = @"1. In the :
+
+   ```
+   Id                                   DisplayName         Description
+   --                                   -----------         -----------
+   62375ab9-6b52-47ed-826b-58e47e0e304b Group.Unified       ...
+   ```";
+        TestParser.TestSpec(input, @"<ol>
+<li><p>In the :</p>
+<pre><code>Id                                   DisplayName         Description
+--                                   -----------         -----------
+62375ab9-6b52-47ed-826b-58e47e0e304b Group.Unified       ...
+</code></pre></li>
+</ol>");
+    }
+
+    [Test]
+    public void VisualizeMathExpressions()
+    {
+        string math = @"Math expressions
+
+$\frac{n!}{k!(n-k)!} = \binom{n}{k}$
+
+$$\frac{n!}{k!(n-k)!} = \binom{n}{k}$$
+
+$$
+\frac{n!}{k!(n-k)!} = \binom{n}{k}
+$$
+
+<div class=""math"">
+\begin{align}
+\sqrt{37} & = \sqrt{\frac{73^2-1}{12^2}} \\
+ & = \sqrt{\frac{73^2}{12^2}\cdot\frac{73^2-1}{73^2}} \\
+ & = \sqrt{\frac{73^2}{12^2}}\sqrt{\frac{73^2-1}{73^2}} \\
+ & = \frac{73}{12}\sqrt{1 - \frac{1}{73^2}} \\
+ & \approx \frac{73}{12}\left(1 - \frac{1}{2\cdot73^2}\right)
+\end{align}
+</div>
+";
+        //Console.WriteLine("Math Expressions:\n");
+        var pl = new MarkdownPipelineBuilder().UseMathematics().Build(); // UseEmphasisExtras(EmphasisExtraOptions.Subscript).Build()
+        var html = Markdown.ToHtml(math, pl);
+        //Console.WriteLine(html);
+    }
+
+    [Test]
+    public void InlineMathExpression()
+    {
+        string math = @"Math expressions
+
+$\frac{n!}{k!(n-k)!} = \binom{n}{k}$
+";
+        var pl = new MarkdownPipelineBuilder().UseMathematics().Build(); // UseEmphasisExtras(EmphasisExtraOptions.Subscript).Build()
+
+        var html = Markdown.ToHtml(math, pl);
+
+        var test1 = html.Contains("<p><span class=\"math\">\\(");
+        var test2 = html.Contains("\\)</span></p>");
+        if (!test1 || !test2)
+        {
+            Console.WriteLine(html);
+        }
+
+        Assert.IsTrue(test1, "Leading bracket missing");
+        Assert.IsTrue(test2, "Trailing bracket missing");
+    }
+
+    [Test]
+    public void BlockMathExpression()
+    {
+        string math = @"Math expressions
+
+$$
+\frac{n!}{k!(n-k)!} = \binom{n}{k}
+$$
+";
+        var pl = new MarkdownPipelineBuilder().UseMathematics().Build(); // UseEmphasisExtras(EmphasisExtraOptions.Subscript).Build()
+
+        var html = Markdown.ToHtml(math, pl);
+        var test1 = html.Contains("<div class=\"math\">\n\\[");
+        var test2 = html.Contains("\\]</div>");
+        if (!test1 || !test2)
+        {
+            Console.WriteLine(html);
+        }
+
+        Assert.IsTrue(test1, "Leading bracket missing");
+        Assert.IsTrue(test2, "Trailing bracket missing");
+    }
+
+    [Test]
+    public void CanDisableParsingHeadings()
+    {
+        var noHeadingsPipeline = new MarkdownPipelineBuilder().DisableHeadings().Build();
+
+        TestParser.TestSpec("Foo\n===", "<h1>Foo</h1>");
+        TestParser.TestSpec("Foo\n===", "<p>Foo\n===</p>", noHeadingsPipeline);
+
+        TestParser.TestSpec("# Heading 1", "<h1>Heading 1</h1>");
+        TestParser.TestSpec("# Heading 1", "<p># Heading 1</p>", noHeadingsPipeline);
+
+        // Does not also disable link reference definitions
+        TestParser.TestSpec("[Foo]\n\n[Foo]: bar", "<p><a href=\"bar\">Foo</a></p>");
+        TestParser.TestSpec("[Foo]\n\n[Foo]: bar", "<p><a href=\"bar\">Foo</a></p>", noHeadingsPipeline);
+    }
+
+    [Test]
+    public void CanOpenAutoLinksInNewWindow()
+    {
+        var pipeline = new MarkdownPipelineBuilder().UseAutoLinks().Build();
+        var newWindowPipeline = new MarkdownPipelineBuilder().UseAutoLinks(new AutoLinkOptions() { OpenInNewWindow = true }).Build();
+
+        TestParser.TestSpec("www.foo.bar", "<p><a href=\"http://www.foo.bar\">www.foo.bar</a></p>", pipeline);
+        TestParser.TestSpec("www.foo.bar", "<p><a href=\"http://www.foo.bar\" target=\"_blank\">www.foo.bar</a></p>", newWindowPipeline);
+    }
+
+    [Test]
+    public void CanUseHttpsPrefixForWWWAutoLinks()
+    {
+        var pipeline = new MarkdownPipelineBuilder().UseAutoLinks().Build();
+        var httpsPipeline = new MarkdownPipelineBuilder().UseAutoLinks(new AutoLinkOptions() { UseHttpsForWWWLinks = true }).Build();
+
+        TestParser.TestSpec("www.foo.bar", "<p><a href=\"http://www.foo.bar\">www.foo.bar</a></p>", pipeline);
+        TestParser.TestSpec("www.foo.bar", "<p><a href=\"https://www.foo.bar\">www.foo.bar</a></p>", httpsPipeline);
+    }
+
+    [Test]
+    public void RootInlineHasCorrectSourceSpan()
+    {
+        var pipeline = new MarkdownPipelineBuilder().UsePreciseSourceLocation().Build();
+        pipeline.TrackTrivia = true;
+
+        var document = Markdown.Parse("0123456789\n", pipeline);
+
+        var expectedSourceSpan = new SourceSpan(0, 10);
+        Assert.That(((LeafBlock)document.LastChild).Inline.Span == expectedSourceSpan);
+    }
+
+    [Test]
+    public void RootInlineInTableCellHasCorrectSourceSpan()
+    {
+        var pipeline = new MarkdownPipelineBuilder().UsePreciseSourceLocation().UseAdvancedExtensions().Build();
+        pipeline.TrackTrivia = true;
+
+        var document = Markdown.Parse("| a | b |\n| --- | --- |\n| <span id=\"dest\"></span><span id=\"DEST\"></span>*dest*<br/> | \\[in\\] The address of the result of the operation.<br/> |", pipeline);
+
+        var paragraph = (ParagraphBlock)((TableCell)((TableRow)((Table)document.LastChild).LastChild).First()).LastChild;
+        Assert.That(paragraph.Inline.Span.Start == paragraph.Inline.FirstChild.Span.Start);
+        Assert.That(paragraph.Inline.Span.End == paragraph.Inline.LastChild.Span.End);
+    }
+
+    [Test]
+    public void TestGridTableShortLine()
+    {
+        var input = @"
++--+
+|  |
++-";
+
+        var expected = @"<table>
+<col style=""width:100%"" />
+<tbody>
+<tr>
+<td></td>
+</tr>
+</tbody>
+</table>
+";
+        TestParser.TestSpec(input, expected, new MarkdownPipelineBuilder().UseGridTables().Build());
+    }
+  
+    [Test]
+    public void TestDefinitionListInListItemWithBlankLine()
+    {
+        var input = @"
+- 
+
+  term
+  :   definition
+";
+
+        var expected = @"<ul>
+<li>
+<dl>
+<dt>term</dt>
+<dd>definition</dd>
+</dl>
+</li>
+</ul>
+";
+        TestParser.TestSpec(input, expected, new MarkdownPipelineBuilder().UseDefinitionLists().Build());
+    }
+
+    [Test]
+    public void TestAlertWithinAlertOrNestedBlock()
+    {
+        var input = @"
+>[!NOTE]
+[!NOTE]
+The second one is not a note.
+
+>>[!NOTE]
+Also not a note.
+";
+
+        var expected = @"<div class=""markdown-alert markdown-alert-note"">
+<p class=""markdown-alert-title""><svg viewBox=""0 0 16 16"" version=""1.1"" width=""16"" height=""16"" aria-hidden=""true""><path d=""M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z""></path></svg>Note</p>
+<p>[!NOTE]
+The second one is not a note.</p>
+</div>
+<blockquote>
+<blockquote>
+<p>[!NOTE]
+Also not a note.</p>
+</blockquote>
+</blockquote>
+";
+        TestParser.TestSpec(input, expected, new MarkdownPipelineBuilder().UseAlertBlocks().Build());
+    }
+
+
+    [Test]
+    public void TestIssue845ListItemBlankLine()
+    {
+        TestParser.TestSpec("-\n\n  foo",@"
+<ul>
+<li></li>
+</ul>
+<p>foo</p>");
+        TestParser.TestSpec("-\n-\n\n  foo",@"
+<ul>
+<li></li>
+<li></li>
+</ul>
+<p>foo</p>");
+        TestParser.TestSpec("-\n\n-\n\n  foo",@"
+<ul>
+<li></li>
+<li></li>
+</ul>
+<p>foo</p>");
+    }
+}

src/Markdig.Tests/NormalizeSpecs/Headings.generated.cs

@@ -0,0 +1,89 @@
+
+// --------------------------------
+//             Headings
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.Normalize.Headings
+{
+    [TestFixture]
+    public class TestHeadings
+    {
+        // # Headings
+        [Test]
+        public void Headings_Example001()
+        {
+            // Example 1
+            // Section: Headings
+            //
+            // The following Markdown:
+            //     # Heading 1
+            //     
+            //     ## Heading 2
+            //     
+            //     ### Heading 3
+            //     
+            //     #### Heading 4
+            //     
+            //     ##### Heading 5
+            //     
+            //     ###### Heading 6
+            //
+            // Should be rendered as:
+            //     # Heading 1
+            //     
+            //     ## Heading 2
+            //     
+            //     ### Heading 3
+            //     
+            //     #### Heading 4
+            //     
+            //     ##### Heading 5
+            //     
+            //     ###### Heading 6
+
+            TestNormalize.TestSpec("# Heading 1\n\n## Heading 2\n\n### Heading 3\n\n#### Heading 4\n\n##### Heading 5\n\n###### Heading 6", "# Heading 1\n\n## Heading 2\n\n### Heading 3\n\n#### Heading 4\n\n##### Heading 5\n\n###### Heading 6", "", context: "Example 1\nSection Headings\n");
+        }
+
+        [Test]
+        public void Headings_Example002()
+        {
+            // Example 2
+            // Section: Headings
+            //
+            // The following Markdown:
+            //     ###### Heading
+            //     
+            //     Text after two newlines
+            //
+            // Should be rendered as:
+            //     ###### Heading
+            //     
+            //     Text after two newlines
+
+            TestNormalize.TestSpec("###### Heading\n\nText after two newlines", "###### Heading\n\nText after two newlines", "", context: "Example 2\nSection Headings\n");
+        }
+
+        [Test]
+        public void Headings_Example003()
+        {
+            // Example 3
+            // Section: Headings
+            //
+            // The following Markdown:
+            //     Heading
+            //     =======
+            //     
+            //     Text after two newlines 1
+            //
+            // Should be rendered as:
+            //     # Heading
+            //     
+            //     Text after two newlines 1
+
+            TestNormalize.TestSpec("Heading\n=======\n\nText after two newlines 1", "# Heading\n\nText after two newlines 1", "", context: "Example 3\nSection Headings\n");
+        }
+    }
+}

src/Markdig.Tests/NormalizeSpecs/Headings.md

@@ -0,0 +1,48 @@
+# Headings
+
+```````````````````````````````` example
+# Heading 1
+
+## Heading 2
+
+### Heading 3
+
+#### Heading 4
+
+##### Heading 5
+
+###### Heading 6
+.
+# Heading 1
+
+## Heading 2
+
+### Heading 3
+
+#### Heading 4
+
+##### Heading 5
+
+###### Heading 6
+````````````````````````````````
+
+```````````````````````````````` example
+###### Heading
+
+Text after two newlines
+.
+###### Heading
+
+Text after two newlines
+````````````````````````````````
+
+```````````````````````````````` example
+Heading
+=======
+
+Text after two newlines 1
+.
+# Heading
+
+Text after two newlines 1
+````````````````````````````````

src/Markdig.Tests/PlainTextSpecs/SamplePlainText.generated.cs

@@ -0,0 +1,33 @@
+
+// --------------------------------
+//              Sample
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.PlainText.Sample
+{
+    [TestFixture]
+    public class TestSamplePlainTextSpec
+    {
+        // # Sample plain text spec
+        // 
+        // Emphasis and anchors are stripped. A newline is ensured.
+        [Test]
+        public void SamplePlainTextSpec_Example001()
+        {
+            // Example 1
+            // Section: Sample plain text spec
+            //
+            // The following Markdown:
+            //     *Hello*, [world](http://example.com)!
+            //
+            // Should be rendered as:
+            //     Hello, world!
+            //     
+
+            TestPlainText.TestSpec("*Hello*, [world](http://example.com)!", "Hello, world!\n", "", context: "Example 1\nSection Sample plain text spec\n");
+        }
+    }
+}

src/Markdig.Tests/PlainTextSpecs/SamplePlainText.md

@@ -0,0 +1,10 @@
+# Sample plain text spec
+
+Emphasis and anchors are stripped. A newline is ensured.
+
+```````````````````````````````` example
+*Hello*, [world](http://example.com)!
+.
+Hello, world!
+
+````````````````````````````````

src/Markdig.Tests/Program.cs

@@ -1,14 +1,16 @@
-// Copyright (c) Alexandre Mutel. All rights reserved.
-// This file is licensed under the BSD-Clause 2 license. 
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
 // See the license.txt file in the project root for more information.
 
-namespace Markdig.Tests
+namespace Markdig.Tests;
+
+class Program
 {
-    public class Program
+    public static void Main(string[] args)
     {
-        public static void Main()
-        {
-            new TestPlayParser().TestSimple();
-        }
+        Console.WriteLine("Run NUnit tests runner with this");
+        // Uncomment the following line to debug a specific tests more easily
+        //var tests = new Specs.CommonMarkV_0_29.TestLeafBlocksSetextHeadings();
+        //tests.LeafBlocksSetextHeadings_Example063();
     }
 }

src/Markdig.Tests/Properties/AssemblyInfo.cs

@@ -1,36 +0,0 @@
-using System.Reflection;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
-
-// General Information about an assembly is controlled through the following 
-// set of attributes. Change these attribute values to modify the information
-// associated with an assembly.
-[assembly: AssemblyTitle("Textamin.Tests")]
-[assembly: AssemblyDescription("")]
-[assembly: AssemblyConfiguration("")]
-[assembly: AssemblyCompany("")]
-[assembly: AssemblyProduct("Textamin.Tests")]
-[assembly: AssemblyCopyright("Copyright ©  2016")]
-[assembly: AssemblyTrademark("")]
-[assembly: AssemblyCulture("")]
-
-// Setting ComVisible to false makes the types in this assembly not visible 
-// to COM components.  If you need to access a type in this assembly from 
-// COM, set the ComVisible attribute to true on that type.
-[assembly: ComVisible(false)]
-
-// The following GUID is for the ID of the typelib if this project is exposed to COM
-[assembly: Guid("a0c5cb5f-5568-40ab-b945-d6d2664d51b0")]
-
-// Version information for an assembly consists of the following four values:
-//
-//      Major Version
-//      Minor Version 
-//      Build Number
-//      Revision
-//
-// You can specify all the values or you can default the Build and Revision Numbers 
-// by using the '*' as shown below:
-// [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.0.0.0")]
-[assembly: AssemblyFileVersion("1.0.0.0")]

src/Markdig.Tests/RoundtripSpecs/Inlines/TestAutoLinkInline.cs

@@ -0,0 +1,23 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestAutoLinkInline
+    {
+        [TestCase("<http://a>")]
+        [TestCase(" <http://a>")]
+        [TestCase("<http://a> ")]
+        [TestCase(" <http://a> ")]
+        [TestCase("<example@example.com>")]
+        [TestCase(" <example@example.com>")]
+        [TestCase("<example@example.com> ")]
+        [TestCase(" <example@example.com> ")]
+        [TestCase("p http://a p")]
+        public void Test(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestBackslashEscapeInline.cs

@@ -0,0 +1,67 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestBackslashEscapeInline
+    {
+        [TestCase(@"\!")]
+        [TestCase(@"\""")]
+        [TestCase(@"\#")]
+        [TestCase(@"\$")]
+        [TestCase(@"\&")]
+        [TestCase(@"\'")]
+        [TestCase(@"\(")]
+        [TestCase(@"\)")]
+        [TestCase(@"\*")]
+        [TestCase(@"\+")]
+        [TestCase(@"\,")]
+        [TestCase(@"\-")]
+        [TestCase(@"\.")]
+        [TestCase(@"\/")]
+        [TestCase(@"\:")]
+        [TestCase(@"\;")]
+        [TestCase(@"\<")]
+        [TestCase(@"\=")]
+        [TestCase(@"\>")]
+        [TestCase(@"\?")]
+        [TestCase(@"\@")]
+        [TestCase(@"\[")]
+        [TestCase(@"\\")]
+        [TestCase(@"\]")]
+        [TestCase(@"\^")]
+        [TestCase(@"\_")]
+        [TestCase(@"\`")]
+        [TestCase(@"\{")]
+        [TestCase(@"\|")]
+        [TestCase(@"\}")]
+        [TestCase(@"\~")]
+
+        // below test breaks visual studio
+        //[TestCase(@"\!\""\#\$\%\&\'\(\)\*\+\,\-\.\/\:\;\<\=\>\?\@\[\\\]\^\_\`\{\|\}\~")]
+        public void Test(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase(@"# \#\#h1")]
+        [TestCase(@"# \#\#h1\#")]
+        public void TestHeading(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase(@"`\``")]
+        [TestCase(@"` \``")]
+        [TestCase(@"`\` `")]
+        [TestCase(@"` \` `")]
+        [TestCase(@" ` \` `")]
+        [TestCase(@"` \` ` ")]
+        [TestCase(@" ` \` ` ")]
+        public void TestCodeSpanInline(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestCodeInline.cs

@@ -0,0 +1,77 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestCodeInline
+    {
+        [TestCase("``")]
+        [TestCase(" ``")]
+        [TestCase("`` ")]
+        [TestCase(" `` ")]
+
+        [TestCase("`c`")]
+        [TestCase(" `c`")]
+        [TestCase("`c` ")]
+        [TestCase(" `c` ")]
+
+        [TestCase("` c`")]
+        [TestCase(" ` c`")]
+        [TestCase("` c` ")]
+        [TestCase(" ` c` ")]
+
+        [TestCase("`c `")]
+        [TestCase(" `c `")]
+        [TestCase("`c ` ")]
+        [TestCase(" `c ` ")]
+
+        [TestCase("`c``")] // 1, 2
+        [TestCase("``c`")] // 2, 1
+        [TestCase("``c``")] // 2, 2
+
+        [TestCase("```c``")] // 2, 3
+        [TestCase("``c```")] // 3, 2
+        [TestCase("```c```")] // 3, 3
+
+        [TestCase("```c````")] // 3, 4
+        [TestCase("````c```")] // 4, 3
+        [TestCase("````c````")] // 4, 4
+
+        [TestCase("```a``` p")]
+        [TestCase("```a`b`c```")]
+        [TestCase("```a``` p\n```a``` p")]
+
+        [TestCase("` a `")]
+        [TestCase(" ` a `")]
+        [TestCase("` a ` ")]
+        [TestCase(" ` a ` ")]
+        public void Test(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase("p `a` p")]
+        [TestCase("p ``a`` p")]
+        [TestCase("p ```a``` p")]
+        [TestCase("p\n\n```a``` p")]
+        public void TestParagraph(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase("`\na\n`")]
+        [TestCase("`\na\r`")]
+        [TestCase("`\na\r\n`")]
+        [TestCase("`\ra\r`")]
+        [TestCase("`\ra\n`")]
+        [TestCase("`\ra\r\n`")]
+        [TestCase("`\r\na\n`")]
+        [TestCase("`\r\na\r`")]
+        [TestCase("`\r\na\r\n`")]
+        public void Test_Newlines(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestEmphasisInline.cs

@@ -0,0 +1,132 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestEmphasisInline
+    {
+        [TestCase("_t_")]
+        [TestCase("_t_t")]
+        [TestCase("t_t_")]
+        [TestCase("_t t_")]
+        [TestCase("_t\tt_")]
+        [TestCase("*t*")]
+        [TestCase("t*t*")]
+        [TestCase("*t*t")]
+        [TestCase("*t t*")]
+        [TestCase("*t\tt*")]
+
+        [TestCase(" _t_")]
+        [TestCase(" _t_t")]
+        [TestCase(" t_t_")]
+        [TestCase(" _t t_")]
+        [TestCase(" _t\tt_")]
+        [TestCase(" *t*")]
+        [TestCase(" t*t*")]
+        [TestCase(" *t*t")]
+        [TestCase(" *t t*")]
+        [TestCase(" *t\tt*")]
+
+        [TestCase("_t_")]
+        [TestCase("_t_t ")]
+        [TestCase("t_t_ ")]
+        [TestCase("_t t_ ")]
+        [TestCase("_t\tt_ ")]
+        [TestCase("*t* ")]
+        [TestCase("t*t* ")]
+        [TestCase("*t*t ")]
+        [TestCase("*t t* ")]
+        [TestCase("*t\tt* ")]
+
+        [TestCase(" _t_")]
+        [TestCase(" _t_t ")]
+        [TestCase(" t_t_ ")]
+        [TestCase(" _t t_ ")]
+        [TestCase(" _t\tt_ ")]
+        [TestCase(" *t* ")]
+        [TestCase(" t*t* ")]
+        [TestCase(" *t*t ")]
+        [TestCase(" *t t* ")]
+        [TestCase(" *t\tt* ")]
+
+        [TestCase("_t_\t")]
+        [TestCase("_t_t\t")]
+        [TestCase("t_t_\t")]
+        [TestCase("_t t_\t")]
+        [TestCase("_t\tt_\t")]
+        [TestCase("*t*\t")]
+        [TestCase("t*t*\t")]
+        [TestCase("*t*t\t")]
+        [TestCase("*t t*\t")]
+        [TestCase("*t\tt*\t")]
+        public void Test_Emphasis(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase("__t__")]
+        [TestCase("__t__t")]
+        [TestCase("t__t__")]
+        [TestCase("__t t__")]
+        [TestCase("__t\tt__")]
+        [TestCase("**t**")]
+        [TestCase("**t**t")]
+        [TestCase("t**t**")]
+        [TestCase("**t\tt**")]
+
+        [TestCase(" __t__")]
+        [TestCase(" __t__t")]
+        [TestCase(" t__t__")]
+        [TestCase(" __t t__")]
+        [TestCase(" __t\tt__")]
+        [TestCase(" **t**")]
+        [TestCase(" **t**t")]
+        [TestCase(" t**t**")]
+        [TestCase(" **t\tt**")]
+
+        [TestCase("__t__ ")]
+        [TestCase("__t__t ")]
+        [TestCase("t__t__ ")]
+        [TestCase("__t t__ ")]
+        [TestCase("__t\tt__ ")]
+        [TestCase("**t** ")]
+        [TestCase("**t**t ")]
+        [TestCase("t**t** ")]
+        [TestCase("**t\tt** ")]
+
+        [TestCase(" __t__ ")]
+        [TestCase(" __t__t ")]
+        [TestCase(" t__t__ ")]
+        [TestCase(" __t t__ ")]
+        [TestCase(" __t\tt__ ")]
+        [TestCase(" **t** ")]
+        [TestCase(" **t** t")]
+        [TestCase(" t**t** ")]
+        [TestCase(" **t\tt** ")]
+
+        [TestCase("__t__\t")]
+        [TestCase("__t__t\t")]
+        [TestCase("t__t__\t ")]
+        [TestCase("__t t__\t ")]
+        [TestCase("__t\tt__\t ")]
+        [TestCase("**t**\t ")]
+        [TestCase("**t**t\t ")]
+        [TestCase("t**t**\t ")]
+        [TestCase("**t\tt**\t ")]
+
+        [TestCase(" __t__\t ")]
+        [TestCase(" __t__t\t ")]
+        [TestCase(" t__t__\t ")]
+        [TestCase(" __t t__\t ")]
+        [TestCase(" __t\tt__\t ")]
+        [TestCase(" **t**\t ")]
+        [TestCase(" **t**\t t")]
+        [TestCase(" t**t**\t ")]
+        [TestCase(" **t\tt**\t ")]
+        public void Test_StrongEmphasis(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestHtmlEntityInline.cs

@@ -0,0 +1,53 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <seealso cref="https://spec.commonmark.org/0.29/#entity-and-numeric-character-references"/>
+    [TestFixture]
+    public class TestHtmlEntityInline
+    {
+        [TestCase("&gt;")]
+        [TestCase("&lt;")]
+        [TestCase("&nbsp;")]
+        [TestCase("&heartsuit;")]
+        [TestCase("&#42;")]
+        [TestCase("&#0;")]
+        [TestCase("&#1234;")]
+        [TestCase("&#xcab;")]
+
+        [TestCase(" &gt;")]
+        [TestCase(" &lt;")]
+        [TestCase(" &nbsp;")]
+        [TestCase(" &heartsuit;")]
+        [TestCase(" &#42;")]
+        [TestCase(" &#0;")]
+        [TestCase(" &#1234;")]
+        [TestCase(" &#xcab;")]
+
+        [TestCase("&gt; ")]
+        [TestCase("&lt; ")]
+        [TestCase("&nbsp; ")]
+        [TestCase("&heartsuit; ")]
+        [TestCase("&#42; ")]
+        [TestCase("&#0; ")]
+        [TestCase("&#1234; ")]
+        [TestCase("&#xcab; ")]
+
+        [TestCase(" &gt; ")]
+        [TestCase(" &lt; ")]
+        [TestCase(" &nbsp; ")]
+        [TestCase(" &heartsuit; ")]
+        [TestCase(" &#42; ")]
+        [TestCase(" &#0; ")]
+        [TestCase(" &#1234; ")]
+        [TestCase(" &#xcab; ")]
+        public void Test(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestHtmlInline.cs

@@ -0,0 +1,27 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestHtmlInline
+    {
+        [TestCase("<em>f</em>")]
+        [TestCase("<em> f</em>")]
+        [TestCase("<em>f </em>")]
+        [TestCase("<em> f </em>")]
+        [TestCase("<b>p</b>")]
+        [TestCase("<b></b>")]
+        [TestCase("<b> </b>")]
+        [TestCase("<b>  </b>")]
+        [TestCase("<b>   </b>")]
+        [TestCase("<b>\t</b>")]
+        [TestCase("<b> \t</b>")]
+        [TestCase("<b>\t </b>")]
+        [TestCase("<b> \t </b>")]
+        public void Test(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestImageInline.cs

@@ -0,0 +1,25 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestImageInline
+    {
+        [TestCase("![](a)")]
+        [TestCase(" ![](a)")]
+        [TestCase("![](a) ")]
+        [TestCase(" ![](a) ")]
+        [TestCase("   ![description](http://example.com)")]
+        public void Test(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase("paragraph   ![description](http://example.com)")]
+        public void TestParagraph(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestLineBreakInline.cs

@@ -0,0 +1,18 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestLineBreakInline
+    {
+        [TestCase("p\n")]
+        [TestCase("p\r\n")]
+        [TestCase("p\r")]
+        [TestCase("[]() ![]()  ``  ` `  `  `  ![]()   ![]()")]
+        public void Test(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestLinkInline.cs

@@ -0,0 +1,229 @@
+using NUnit.Framework;
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestLinkInline
+    {
+        [TestCase("[a]")] // TODO: this is not a link but a paragraph
+        [TestCase("[a]()")]
+
+        [TestCase("[](b)")]
+        [TestCase(" [](b)")]
+        [TestCase("[](b) ")]
+        [TestCase(" [](b) ")]
+
+        [TestCase("[a](b)")]
+        [TestCase(" [a](b)")]
+        [TestCase("[a](b) ")]
+        [TestCase(" [a](b) ")]
+
+        [TestCase("[ a](b)")]
+        [TestCase(" [ a](b)")]
+        [TestCase("[ a](b) ")]
+        [TestCase(" [ a](b) ")]
+
+        [TestCase("[a ](b)")]
+        [TestCase(" [a ](b)")]
+        [TestCase("[a ](b) ")]
+        [TestCase(" [a ](b) ")]
+
+        [TestCase("[ a ](b)")]
+        [TestCase(" [ a ](b)")]
+        [TestCase("[ a ](b) ")]
+        [TestCase(" [ a ](b) ")]
+
+        // below cases are required for a full roundtrip but not have low prio for impl
+        [TestCase("[]( b)")]
+        [TestCase(" []( b)")]
+        [TestCase("[]( b) ")]
+        [TestCase(" []( b) ")]
+
+        [TestCase("[a]( b)")]
+        [TestCase(" [a]( b)")]
+        [TestCase("[a]( b) ")]
+        [TestCase(" [a]( b) ")]
+
+        [TestCase("[ a]( b)")]
+        [TestCase(" [ a]( b)")]
+        [TestCase("[ a]( b) ")]
+        [TestCase(" [ a]( b) ")]
+
+        [TestCase("[a ]( b)")]
+        [TestCase(" [a ]( b)")]
+        [TestCase("[a ]( b) ")]
+        [TestCase(" [a ]( b) ")]
+
+        [TestCase("[ a ]( b)")]
+        [TestCase(" [ a ]( b)")]
+        [TestCase("[ a ]( b) ")]
+        [TestCase(" [ a ]( b) ")]
+
+        [TestCase("[](b )")]
+        [TestCase(" [](b )")]
+        [TestCase("[](b ) ")]
+        [TestCase(" [](b ) ")]
+
+        [TestCase("[a](b )")]
+        [TestCase(" [a](b )")]
+        [TestCase("[a](b ) ")]
+        [TestCase(" [a](b ) ")]
+
+        [TestCase("[ a](b )")]
+        [TestCase(" [ a](b )")]
+        [TestCase("[ a](b ) ")]
+        [TestCase(" [ a](b ) ")]
+
+        [TestCase("[a ](b )")]
+        [TestCase(" [a ](b )")]
+        [TestCase("[a ](b ) ")]
+        [TestCase(" [a ](b ) ")]
+
+        [TestCase("[ a ](b )")]
+        [TestCase(" [ a ](b )")]
+        [TestCase("[ a ](b ) ")]
+        [TestCase(" [ a ](b ) ")]
+
+        [TestCase("[]( b )")]
+        [TestCase(" []( b )")]
+        [TestCase("[]( b ) ")]
+        [TestCase(" []( b ) ")]
+
+        [TestCase("[a]( b )")]
+        [TestCase(" [a]( b )")]
+        [TestCase("[a]( b ) ")]
+        [TestCase(" [a]( b ) ")]
+
+        [TestCase("[ a]( b )")]
+        [TestCase(" [ a]( b )")]
+        [TestCase("[ a]( b ) ")]
+        [TestCase(" [ a]( b ) ")]
+
+        [TestCase("[a ]( b )")]
+        [TestCase(" [a ]( b )")]
+        [TestCase("[a ]( b ) ")]
+        [TestCase(" [a ]( b ) ")]
+
+        [TestCase("[ a ]( b )")]
+        [TestCase(" [ a ]( b )")]
+        [TestCase("[ a ]( b ) ")]
+        [TestCase(" [ a ]( b ) ")]
+        public void Test(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase("[a](b \"t\") ")]
+        [TestCase("[a](b \" t\") ")]
+        [TestCase("[a](b \"t \") ")]
+        [TestCase("[a](b \" t \") ")]
+
+        [TestCase("[a](b  \"t\") ")]
+        [TestCase("[a](b  \" t\") ")]
+        [TestCase("[a](b  \"t \") ")]
+        [TestCase("[a](b  \" t \") ")]
+
+        [TestCase("[a](b \"t\" ) ")]
+        [TestCase("[a](b \" t\" ) ")]
+        [TestCase("[a](b \"t \" ) ")]
+        [TestCase("[a](b \" t \" ) ")]
+
+        [TestCase("[a](b  \"t\" ) ")]
+        [TestCase("[a](b  \" t\" ) ")]
+        [TestCase("[a](b  \"t \" ) ")]
+        [TestCase("[a](b  \" t \" ) ")]
+
+        [TestCase("[a](b 't') ")]
+        [TestCase("[a](b ' t') ")]
+        [TestCase("[a](b 't ') ")]
+        [TestCase("[a](b ' t ') ")]
+
+        [TestCase("[a](b  't') ")]
+        [TestCase("[a](b  ' t') ")]
+        [TestCase("[a](b  't ') ")]
+        [TestCase("[a](b  ' t ') ")]
+
+        [TestCase("[a](b 't' ) ")]
+        [TestCase("[a](b ' t' ) ")]
+        [TestCase("[a](b 't ' ) ")]
+        [TestCase("[a](b ' t ' ) ")]
+
+        [TestCase("[a](b  't' ) ")]
+        [TestCase("[a](b  ' t' ) ")]
+        [TestCase("[a](b  't ' ) ")]
+        [TestCase("[a](b  ' t ' ) ")]
+
+        [TestCase("[a](b (t)) ")]
+        [TestCase("[a](b ( t)) ")]
+        [TestCase("[a](b (t )) ")]
+        [TestCase("[a](b ( t )) ")]
+
+        [TestCase("[a](b  (t)) ")]
+        [TestCase("[a](b  ( t)) ")]
+        [TestCase("[a](b  (t )) ")]
+        [TestCase("[a](b  ( t )) ")]
+
+        [TestCase("[a](b (t) ) ")]
+        [TestCase("[a](b ( t) ) ")]
+        [TestCase("[a](b (t ) ) ")]
+        [TestCase("[a](b ( t ) ) ")]
+
+        [TestCase("[a](b  (t) ) ")]
+        [TestCase("[a](b  ( t) ) ")]
+        [TestCase("[a](b  (t ) ) ")]
+        [TestCase("[a](b  ( t ) ) ")]
+        public void Test_Title(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase("[a](<>)")]
+        [TestCase("[a]( <>)")]
+        [TestCase("[a](<> )")]
+        [TestCase("[a]( <> )")]
+
+        [TestCase("[a](< >)")]
+        [TestCase("[a]( < >)")]
+        [TestCase("[a](< > )")]
+        [TestCase("[a]( < > )")]
+
+        [TestCase("[a](<b>)")]
+        [TestCase("[a](<b >)")]
+        [TestCase("[a](< b>)")]
+        [TestCase("[a](< b >)")]
+
+        [TestCase("[a](<b b>)")]
+        [TestCase("[a](<b b >)")]
+        [TestCase("[a](< b b >)")]
+        public void Test_PointyBrackets(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase("[*a*][a]")]
+        [TestCase("[a][b]")]
+        [TestCase("[a][]")]
+        [TestCase("[a]")]
+        public void Test_Inlines(string value)
+        {
+            RoundTrip(value);
+        }
+
+        // | [ a ]( b " t " ) |
+        [TestCase(" [ a ]( b \" t \" ) ")]
+        [TestCase("\v[\va\v](\vb\v\"\vt\v\"\v)\v")]
+        [TestCase("\f[\fa\f](\fb\f\"\ft\f\"\f)\f")]
+        [TestCase("\t[\ta\t](\tb\t\"\tt\t\"\t)\t")]
+        public void Test_UncommonWhitespace(string value)
+        {
+            RoundTrip(value);
+        }
+
+        [TestCase("[x]: https://example.com\r\n")]
+        public void Test_LinkReferenceDefinitionWithCarriageReturnLineFeed(string value)
+        {
+            RoundTrip(value);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/Inlines/TestNullCharacterInline.cs

@@ -0,0 +1,37 @@
+using Markdig.Renderers.Roundtrip;
+using Markdig.Syntax;
+using NUnit.Framework;
+using System.IO;
+
+namespace Markdig.Tests.RoundtripSpecs.Inlines
+{
+    [TestFixture]
+    public class TestNullCharacterInline
+    {
+        [TestCase("\0", "\uFFFD")]
+        [TestCase("\0p", "\uFFFDp")]
+        [TestCase("p\0", "p\uFFFD")]
+        [TestCase("p\0p", "p\uFFFDp")]
+        [TestCase("p\0\0p", "p\uFFFD\uFFFDp")] // I promise you, this was not intentional
+        public void Test(string value, string expected)
+        {
+            RoundTrip(value, expected);
+        }
+
+        // this method is copied intentionally to ensure all other tests
+        // do not unintentionally use the expected parameter
+        private static void RoundTrip(string markdown, string expected)
+        {
+            var pipelineBuilder = new MarkdownPipelineBuilder();
+            pipelineBuilder.EnableTrackTrivia();
+            MarkdownPipeline pipeline = pipelineBuilder.Build();
+            MarkdownDocument markdownDocument = Markdown.Parse(markdown, pipeline);
+            var sw = new StringWriter();
+            var rr = new RoundtripRenderer(sw);
+
+            rr.Write(markdownDocument);
+
+            Assert.AreEqual(expected, sw.ToString());
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestAtxHeading.cs

@@ -0,0 +1,53 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestAtxHeading
+{
+    [TestCase("# h")]
+    [TestCase("# h ")]
+    [TestCase("# h\n#h")]
+    [TestCase("# h\n #h")]
+    [TestCase("# h\n # h")]
+    [TestCase("# h\n # h ")]
+    [TestCase(" #  h   \n    #     h      ")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("\n# h\n\np")]
+    [TestCase("\n# h\n\np\n")]
+    [TestCase("\n# h\n\np\n\n")]
+    [TestCase("\n\n# h\n\np\n\n")]
+    [TestCase("\n\n# h\np\n\n")]
+    [TestCase("\n\n# h\np\n\n")]
+    public void TestParagraph(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("\n# h")]
+    [TestCase("\n# h\n")]
+    [TestCase("\n# h\r")]
+    [TestCase("\n# h\r\n")]
+
+    [TestCase("\r# h")]
+    [TestCase("\r# h\n")]
+    [TestCase("\r# h\r")]
+    [TestCase("\r# h\r\n")]
+
+    [TestCase("\r\n# h")]
+    [TestCase("\r\n# h\n")]
+    [TestCase("\r\n# h\r")]
+    [TestCase("\r\n# h\r\n")]
+
+    [TestCase("# h\n\n ")]
+    [TestCase("# h\n\n  ")]
+    [TestCase("# h\n\n   ")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestExample.cs

@@ -0,0 +1,58 @@
+using Markdig.Helpers;
+using Markdig.Renderers.Roundtrip;
+using Markdig.Syntax;
+using Markdig.Syntax.Inlines;
+using NUnit.Framework;
+using System.IO;
+
+namespace Markdig.Tests.RoundtripSpecs
+{
+    [TestFixture]
+    public class TestExample
+    {
+        [Test]
+        public void Test()
+        {
+            var markdown = $@"
+# Test document
+This document contains an unordered list. It uses tabs to indent. This test demonstrates
+a method of making the input markdown uniform without altering any other markdown in the
+resulting output file.
+
+- item1
+
+>look, ma:
+> my space is not normalized!
+";
+            MarkdownDocument markdownDocument = Markdown.Parse(markdown, trackTrivia: true);
+            var listBlock = markdownDocument[2] as ListBlock;
+            var listItem = listBlock[0] as ListItemBlock;
+            var paragraph = listItem[0] as ParagraphBlock;
+            var containerInline = new ContainerInline();
+            containerInline.AppendChild(new LiteralInline(" my own text!"));
+            containerInline.AppendChild(new LineBreakInline { NewLine = NewLine.CarriageReturnLineFeed });
+            paragraph.Inline = containerInline;
+
+            var sw = new StringWriter();
+            var rr = new RoundtripRenderer(sw);
+            rr.Write(markdownDocument);
+            var outputMarkdown = sw.ToString();
+            var expected = $@"
+# Test document
+This document contains an unordered list. It uses tabs to indent. This test demonstrates
+a method of making the input markdown uniform without altering any other markdown in the
+resulting output file.
+
+- my own text!
+
+>look, ma:
+> my space is not normalized!
+";
+
+            expected = expected.Replace("\r\n", "\n").Replace("\r", "\n");
+            outputMarkdown = outputMarkdown.Replace("\r\n", "\n").Replace("\r", "\n");
+
+            Assert.AreEqual(expected, outputMarkdown);
+        }
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestFencedCodeBlock.cs

@@ -0,0 +1,105 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestFencedCodeBlock
+{
+    [TestCase("```\nc\n```")]
+    [TestCase("```\nc\n```\n")]
+    [TestCase("\n```\nc\n```")]
+    [TestCase("\n\n```\nc\n```")]
+    [TestCase("```\nc\n```\n")]
+    [TestCase("```\nc\n```\n\n")]
+    [TestCase("\n```\nc\n```\n")]
+    [TestCase("\n```\nc\n```\n\n")]
+    [TestCase("\n\n```\nc\n```\n")]
+    [TestCase("\n\n```\nc\n```\n\n")]
+
+    [TestCase(" ```\nc\n````")]
+    [TestCase("```\nc\n````")]
+    [TestCase("p\n\n```\nc\n```")]
+
+    [TestCase("```\n c\n```")]
+    [TestCase("```\nc \n```")]
+    [TestCase("```\n c \n```")]
+
+    [TestCase(" ``` \n c \n ``` ")]
+    [TestCase("\t```\t\n\tc\t\n\t```\t")]
+    [TestCase("\v```\v\n\vc\v\n\v```\v")]
+    [TestCase("\f```\f\n\fc\f\n\f```\f")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("~~~ aa ``` ~~~\nfoo\n~~~")]
+    [TestCase("~~~ aa ``` ~~~\nfoo\n~~~ ")]
+    public void TestTilde(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("```\n c \n```")]
+    [TestCase("```\n c \r```")]
+    [TestCase("```\n c \r\n```")]
+    [TestCase("```\r c \n```")]
+    [TestCase("```\r c \r```")]
+    [TestCase("```\r c \r\n```")]
+    [TestCase("```\r\n c \n```")]
+    [TestCase("```\r\n c \r```")]
+    [TestCase("```\r\n c \r\n```")]
+
+    [TestCase("```\n c \n```\n")]
+    [TestCase("```\n c \r```\n")]
+    [TestCase("```\n c \r\n```\n")]
+    [TestCase("```\r c \n```\n")]
+    [TestCase("```\r c \r```\n")]
+    [TestCase("```\r c \r\n```\n")]
+    [TestCase("```\r\n c \n```\n")]
+    [TestCase("```\r\n c \r```\n")]
+    [TestCase("```\r\n c \r\n```\n")]
+
+    [TestCase("```\n c \n```\r")]
+    [TestCase("```\n c \r```\r")]
+    [TestCase("```\n c \r\n```\r")]
+    [TestCase("```\r c \n```\r")]
+    [TestCase("```\r c \r```\r")]
+    [TestCase("```\r c \r\n```\r")]
+    [TestCase("```\r\n c \n```\r")]
+    [TestCase("```\r\n c \r```\r")]
+    [TestCase("```\r\n c \r\n```\r")]
+
+    [TestCase("```\n c \n```\r\n")]
+    [TestCase("```\n c \r```\r\n")]
+    [TestCase("```\n c \r\n```\r\n")]
+    [TestCase("```\r c \n```\r\n")]
+    [TestCase("```\r c \r```\r\n")]
+    [TestCase("```\r c \r\n```\r\n")]
+    [TestCase("```\r\n c \n```\r\n")]
+    [TestCase("```\r\n c \r```\r\n")]
+    [TestCase("```\r\n c \r\n```\r\n")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("```i a\n```")]
+    [TestCase("```i a a2\n```")]
+    [TestCase("```i a a2 a3\n```")]
+    [TestCase("```i a a2 a3 a4\n```")]
+
+    [TestCase("```i\ta\n```")]
+    [TestCase("```i\ta a2\n```")]
+    [TestCase("```i\ta a2 a3\n```")]
+    [TestCase("```i\ta a2 a3 a4\n```")]
+
+    [TestCase("```i\ta \n```")]
+    [TestCase("```i\ta a2 \n```")]
+    [TestCase("```i\ta a2 a3 \n```")]
+    [TestCase("```i\ta a2 a3 a4 \n```")]
+    public void TestInfoArguments(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestHtmlBlock.cs

@@ -0,0 +1,18 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestHtmlBlock
+{
+    [TestCase("<br>")]
+    [TestCase("<br>\n")]
+    [TestCase("<br>\n\n")]
+    [TestCase("<div></div>\n\n# h")]
+    [TestCase("p\n\n<div></div>\n")]
+    [TestCase("<div></div>\n\n# h")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestIndentedCodeBlock.cs

@@ -0,0 +1,84 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestIndentedCodeBlock
+{
+    // A codeblock is indented with 4 spaces. After the 4th space, whitespace is interpreted as content.
+    // l = line
+    [TestCase("    l")]
+    [TestCase("     l")]
+    [TestCase("\tl")]
+    [TestCase("\t\tl")]
+    [TestCase("\tl1\n    l1")]
+
+    [TestCase("\n    l")]
+    [TestCase("\n\n    l")]
+    [TestCase("\n    l\n")]
+    [TestCase("\n    l\n\n")]
+    [TestCase("\n\n    l\n")]
+    [TestCase("\n\n    l\n\n")]
+
+    [TestCase("    l\n    l")]
+    [TestCase("    l\n    l\n    l")]
+
+
+    // two newlines are needed for indented codeblock start after paragraph
+    [TestCase("p\n\n    l")]
+    [TestCase("p\n\n    l\n")]
+    [TestCase("p\n\n    l\n\n")]
+
+    [TestCase("p\n\n    l\n    l")]
+    [TestCase("p\n\n    l\n     l")]
+
+    [TestCase("    l\n\np\n\n    l")]
+    [TestCase("    l    l\n\np\n\n    l    l")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("    l\n")]
+    [TestCase("    l\r")]
+    [TestCase("    l\r\n")]
+
+    [TestCase("    l\n    l")]
+    [TestCase("    l\n    l\n")]
+    [TestCase("    l\n    l\r")]
+    [TestCase("    l\n    l\r\n")]
+
+    [TestCase("    l\r    l")]
+    [TestCase("    l\r    l\n")]
+    [TestCase("    l\r    l\r")]
+    [TestCase("    l\r    l\r\n")]
+
+    [TestCase("    l\r\n    l")]
+    [TestCase("    l\r\n    l\n")]
+    [TestCase("    l\r\n    l\r")]
+    [TestCase("    l\r\n    l\r\n")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("    l\n\n    l\n")]
+    [TestCase("    l\n\n\n    l\n")]
+    public void TestNewlinesInBetweenResultInOneCodeBlock(string value)
+    {
+        var pipelineBuilder = new MarkdownPipelineBuilder();
+        pipelineBuilder.EnableTrackTrivia();
+        MarkdownPipeline pipeline = pipelineBuilder.Build();
+        var markdownDocument = Markdown.Parse(value, pipeline);
+
+        Assert.AreEqual(1, markdownDocument.Count);
+    }
+
+    [TestCase("    l\n\np")]
+    [TestCase("    l\n\n\np")]
+    [TestCase("    l\n\n\n\np")]
+    public void TestParagraph(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestLinkReferenceDefinition.cs

@@ -0,0 +1,212 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestLinkReferenceDefinition
+{
+    [TestCase(@"[a]: /r")]
+    [TestCase(@" [a]: /r")]
+    [TestCase(@"  [a]: /r")]
+    [TestCase(@"   [a]: /r")]
+
+    [TestCase(@"[a]:  /r")]
+    [TestCase(@" [a]:  /r")]
+    [TestCase(@"  [a]:  /r")]
+    [TestCase(@"   [a]:  /r")]
+
+    [TestCase(@"[a]:  /r ")]
+    [TestCase(@" [a]:  /r ")]
+    [TestCase(@"  [a]:  /r ")]
+    [TestCase(@"   [a]:  /r ")]
+
+    [TestCase(@"[a]: /r ""l""")]
+    [TestCase(@"[a]:  /r ""l""")]
+    [TestCase(@"[a]: /r  ""l""")]
+    [TestCase(@"[a]: /r ""l"" ")]
+    [TestCase(@"[a]:  /r  ""l""")]
+    [TestCase(@"[a]:  /r  ""l"" ")]
+
+    [TestCase(@" [a]: /r ""l""")]
+    [TestCase(@" [a]:  /r ""l""")]
+    [TestCase(@" [a]: /r  ""l""")]
+    [TestCase(@" [a]: /r ""l"" ")]
+    [TestCase(@" [a]:  /r  ""l""")]
+    [TestCase(@" [a]:  /r  ""l"" ")]
+
+    [TestCase(@"  [a]: /r ""l""")]
+    [TestCase(@"  [a]:  /r ""l""")]
+    [TestCase(@"  [a]: /r  ""l""")]
+    [TestCase(@"  [a]: /r ""l"" ")]
+    [TestCase(@"  [a]:  /r  ""l""")]
+    [TestCase(@"  [a]:  /r  ""l"" ")]
+
+    [TestCase(@"   [a]: /r ""l""")]
+    [TestCase(@"   [a]:  /r ""l""")]
+    [TestCase(@"   [a]: /r  ""l""")]
+    [TestCase(@"   [a]: /r ""l"" ")]
+    [TestCase(@"   [a]:  /r  ""l""")]
+    [TestCase(@"   [a]:  /r  ""l"" ")]
+
+    [TestCase("[a]:\t/r")]
+    [TestCase("[a]:\t/r\t")]
+    [TestCase("[a]:\t/r\t\"l\"")]
+    [TestCase("[a]:\t/r\t\"l\"\t")]
+
+    [TestCase("[a]: \t/r")]
+    [TestCase("[a]: \t/r\t")]
+    [TestCase("[a]: \t/r\t\"l\"")]
+    [TestCase("[a]: \t/r\t\"l\"\t")]
+
+    [TestCase("[a]:\t /r")]
+    [TestCase("[a]:\t /r\t")]
+    [TestCase("[a]:\t /r\t\"l\"")]
+    [TestCase("[a]:\t /r\t\"l\"\t")]
+
+    [TestCase("[a]: \t /r")]
+    [TestCase("[a]: \t /r\t")]
+    [TestCase("[a]: \t /r\t\"l\"")]
+    [TestCase("[a]: \t /r\t\"l\"\t")]
+
+    [TestCase("[a]:\t/r \t")]
+    [TestCase("[a]:\t/r \t\"l\"")]
+    [TestCase("[a]:\t/r \t\"l\"\t")]
+
+    [TestCase("[a]: \t/r")]
+    [TestCase("[a]: \t/r \t")]
+    [TestCase("[a]: \t/r \t\"l\"")]
+    [TestCase("[a]: \t/r \t\"l\"\t")]
+
+    [TestCase("[a]:\t /r")]
+    [TestCase("[a]:\t /r \t")]
+    [TestCase("[a]:\t /r \t\"l\"")]
+    [TestCase("[a]:\t /r \t\"l\"\t")]
+
+    [TestCase("[a]: \t /r")]
+    [TestCase("[a]: \t /r \t")]
+    [TestCase("[a]: \t /r \t\"l\"")]
+    [TestCase("[a]: \t /r \t\"l\"\t")]
+
+    [TestCase("[a]:\t/r\t ")]
+    [TestCase("[a]:\t/r\t \"l\"")]
+    [TestCase("[a]:\t/r\t \"l\"\t")]
+
+    [TestCase("[a]: \t/r")]
+    [TestCase("[a]: \t/r\t ")]
+    [TestCase("[a]: \t/r\t \"l\"")]
+    [TestCase("[a]: \t/r\t \"l\"\t")]
+
+    [TestCase("[a]:\t /r")]
+    [TestCase("[a]:\t /r\t ")]
+    [TestCase("[a]:\t /r\t \"l\"")]
+    [TestCase("[a]:\t /r\t \"l\"\t")]
+
+    [TestCase("[a]: \t /r")]
+    [TestCase("[a]: \t /r\t ")]
+    [TestCase("[a]: \t /r\t \"l\"")]
+    [TestCase("[a]: \t /r\t \"l\"\t")]
+
+    [TestCase("[a]:\t/r \t ")]
+    [TestCase("[a]:\t/r \t \"l\"")]
+    [TestCase("[a]:\t/r \t \"l\"\t")]
+
+    [TestCase("[a]: \t/r")]
+    [TestCase("[a]: \t/r \t ")]
+    [TestCase("[a]: \t/r \t \"l\"")]
+    [TestCase("[a]: \t/r \t \"l\"\t")]
+
+    [TestCase("[a]:\t /r")]
+    [TestCase("[a]:\t /r \t ")]
+    [TestCase("[a]:\t /r \t \"l\"")]
+    [TestCase("[a]:\t /r \t \"l\"\t")]
+
+    [TestCase("[a]: \t /r")]
+    [TestCase("[a]: \t /r \t ")]
+    [TestCase("[a]: \t /r \t \"l\"")]
+    [TestCase("[a]: \t /r \t \"l\"\t")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("[a]: /r\n[b]: /r\n")]
+    [TestCase("[a]: /r\n[b]: /r\n[c] /r\n")]
+    public void TestMultiple(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("[a]:\f/r\f\"l\"")]
+    [TestCase("[a]:\v/r\v\"l\"")]
+    public void TestUncommonWhitespace(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("[a]:\n/r\n\"t\"")]
+    [TestCase("[a]:\n/r\r\"t\"")]
+    [TestCase("[a]:\n/r\r\n\"t\"")]
+
+    [TestCase("[a]:\r/r\n\"t\"")]
+    [TestCase("[a]:\r/r\r\"t\"")]
+    [TestCase("[a]:\r/r\r\n\"t\"")]
+
+    [TestCase("[a]:\r\n/r\n\"t\"")]
+    [TestCase("[a]:\r\n/r\r\"t\"")]
+    [TestCase("[a]:\r\n/r\r\n\"t\"")]
+
+    [TestCase("[a]:\n/r\n\"t\nt\"")]
+    [TestCase("[a]:\n/r\n\"t\rt\"")]
+    [TestCase("[a]:\n/r\n\"t\r\nt\"")]
+
+    [TestCase("[a]:\r\n  /r\t \n \t \"t\r\nt\"   ")]
+    [TestCase("[a]:\n/r\n\n[a],")]
+    [TestCase("[a]: /r\n[b]: /r\n\n[a],")]
+    public void TestNewlines(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("[ a]: /r")]
+    [TestCase("[a ]: /r")]
+    [TestCase("[ a ]: /r")]
+    [TestCase("[  a]: /r")]
+    [TestCase("[  a ]: /r")]
+    [TestCase("[a  ]: /r")]
+    [TestCase("[ a  ]: /r")]
+    [TestCase("[  a  ]: /r")]
+    [TestCase("[a a]: /r")]
+    [TestCase("[a\va]: /r")]
+    [TestCase("[a\fa]: /r")]
+    [TestCase("[a\ta]: /r")]
+    [TestCase("[\va]: /r")]
+    [TestCase("[\fa]: /r")]
+    [TestCase("[\ta]: /r")]
+    [TestCase(@"[\]]: /r")]
+    public void TestLabel(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("[a]: /r ()")]
+    [TestCase("[a]: /r (t)")]
+    [TestCase("[a]: /r ( t)")]
+    [TestCase("[a]: /r (t )")]
+    [TestCase("[a]: /r ( t )")]
+
+    [TestCase("[a]: /r ''")]
+    [TestCase("[a]: /r 't'")]
+    [TestCase("[a]: /r ' t'")]
+    [TestCase("[a]: /r 't '")]
+    [TestCase("[a]: /r ' t '")]
+    public void Test_Title(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("[a]: /r\n===\n[a]")]
+    public void TestSetextHeader(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestNoBlocksFoundBlock.cs

@@ -0,0 +1,21 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestNoBlocksFoundBlock
+{
+    [TestCase("\r")]
+    [TestCase("\n")]
+    [TestCase("\r\n")]
+    [TestCase("\t")]
+    [TestCase("\v")]
+    [TestCase("\f")]
+    [TestCase(" ")]
+    [TestCase("  ")]
+    [TestCase("   ")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestOrderedList.cs

@@ -0,0 +1,189 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestOrderedList
+{
+    [TestCase("1. i")]
+    [TestCase("1.  i")]
+    [TestCase("1. i ")]
+    [TestCase("1.  i ")]
+    [TestCase("1.  i  ")]
+
+    [TestCase(" 1. i")]
+    [TestCase(" 1.  i")]
+    [TestCase(" 1. i ")]
+    [TestCase(" 1.  i ")]
+    [TestCase(" 1.  i  ")]
+
+    [TestCase("  1. i")]
+    [TestCase("  1.  i")]
+    [TestCase("  1. i ")]
+    [TestCase("  1.  i ")]
+    [TestCase("  1.  i  ")]
+
+    [TestCase("   1. i")]
+    [TestCase("   1.  i")]
+    [TestCase("   1. i ")]
+    [TestCase("   1.  i ")]
+    [TestCase("   1.  i  ")]
+
+    [TestCase("1. i\n")]
+    [TestCase("1.  i\n")]
+    [TestCase("1. i \n")]
+    [TestCase("1.  i \n")]
+    [TestCase("1.  i  \n")]
+
+    [TestCase(" 1. i\n")]
+    [TestCase(" 1.  i\n")]
+    [TestCase(" 1. i \n")]
+    [TestCase(" 1.  i \n")]
+    [TestCase(" 1.  i  \n")]
+
+    [TestCase("  1. i\n")]
+    [TestCase("  1.  i\n")]
+    [TestCase("  1. i \n")]
+    [TestCase("  1.  i \n")]
+    [TestCase("  1.  i  \n")]
+
+    [TestCase("   1. i\n")]
+    [TestCase("   1.  i\n")]
+    [TestCase("   1. i \n")]
+    [TestCase("   1.  i \n")]
+    [TestCase("   1.  i  \n")]
+
+    [TestCase("1. i\n2. j")]
+    [TestCase("1.  i\n2. j")]
+    [TestCase("1. i \n2. j")]
+    [TestCase("1.  i \n2. j")]
+    [TestCase("1.  i  \n2. j")]
+
+    [TestCase(" 1. i\n2. j")]
+    [TestCase(" 1.  i\n2. j")]
+    [TestCase(" 1. i \n2. j")]
+    [TestCase(" 1.  i \n2. j")]
+    [TestCase(" 1.  i  \n2. j")]
+
+    [TestCase("  1. i\n2. j")]
+    [TestCase("  1.  i\n2. j")]
+    [TestCase("  1. i \n2. j")]
+    [TestCase("  1.  i \n2. j")]
+    [TestCase("  1.  i  \n2. j")]
+
+    [TestCase("   1. i\n2. j")]
+    [TestCase("   1.  i\n2. j")]
+    [TestCase("   1. i \n2. j")]
+    [TestCase("   1.  i \n2. j")]
+    [TestCase("   1.  i  \n2. j")]
+
+    [TestCase("1. i\n2. j\n")]
+    [TestCase("1.  i\n2. j\n")]
+    [TestCase("1. i \n2. j\n")]
+    [TestCase("1.  i \n2. j\n")]
+    [TestCase("1.  i  \n2. j\n")]
+
+    [TestCase(" 1. i\n2. j\n")]
+    [TestCase(" 1.  i\n2. j\n")]
+    [TestCase(" 1. i \n2. j\n")]
+    [TestCase(" 1.  i \n2. j\n")]
+    [TestCase(" 1.  i  \n2. j\n")]
+
+    [TestCase("  1. i\n2. j\n")]
+    [TestCase("  1.  i\n2. j\n")]
+    [TestCase("  1. i \n2. j\n")]
+    [TestCase("  1.  i \n2. j\n")]
+    [TestCase("  1.  i  \n2. j\n")]
+
+    [TestCase("   1. i\n2. j\n")]
+    [TestCase("   1.  i\n2. j\n")]
+    [TestCase("   1. i \n2. j\n")]
+    [TestCase("   1.  i \n2. j\n")]
+    [TestCase("   1.  i  \n2. j\n")]
+
+    [TestCase("1. i\n2. j\n3. k")]
+    [TestCase("1. i\n2. j\n3. k\n")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("10. i")]
+    [TestCase("11. i")]
+    [TestCase("10. i\n12. i")]
+    [TestCase("2. i\n3. i")]
+    public void Test_MoreThenOneStart(string value)
+    {
+        RoundTrip(value);
+    }
+
+
+    [TestCase("\n1. i")]
+    [TestCase("\r1. i")]
+    [TestCase("\r\n1. i")]
+
+    [TestCase("\n1. i\n")]
+    [TestCase("\r1. i\n")]
+    [TestCase("\r\n1. i\n")]
+
+    [TestCase("\n1. i\r")]
+    [TestCase("\r1. i\r")]
+    [TestCase("\r\n1. i\r")]
+
+    [TestCase("\n1. i\r\n")]
+    [TestCase("\r1. i\r\n")]
+    [TestCase("\r\n1. i\r\n")]
+
+    [TestCase("1. i\n2. i")]
+    [TestCase("\n1. i\n2. i")]
+    [TestCase("\r1. i\n2. i")]
+    [TestCase("\r\n1. i\n2. i")]
+
+    [TestCase("1. i\r2. i")]
+    [TestCase("\n1. i\r2. i")]
+    [TestCase("\r1. i\r2. i")]
+    [TestCase("\r\n1. i\r2. i")]
+
+    [TestCase("1. i\r\n2. i")]
+    [TestCase("\n1. i\r\n2. i")]
+    [TestCase("\r1. i\r\n2. i")]
+    [TestCase("\r\n1. i\r\n2. i")]
+
+    [TestCase("1. i\n2. i\n")]
+    [TestCase("\n1. i\n2. i\n")]
+    [TestCase("\r1. i\n2. i\n")]
+    [TestCase("\r\n1. i\n2. i\n")]
+
+    [TestCase("1. i\r2. i\r")]
+    [TestCase("\n1. i\r2. i\r")]
+    [TestCase("\r1. i\r2. i\r")]
+    [TestCase("\r\n1. i\r2. i\r")]
+
+    [TestCase("1. i\r\n2. i\r\n")]
+    [TestCase("\n1. i\r\n2. i\r\n")]
+    [TestCase("\r1. i\r\n2. i\r\n")]
+    [TestCase("\r\n1. i\r\n2. i\r\n")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("1. i\n  1. i")]
+    [TestCase("1. i\n  1. i\n")]
+    [TestCase("1. i\n  1. i\n  2. i")]
+    [TestCase("1. i\n  2. i\n  3. i")]
+
+    [TestCase("1. i\n\t1. i")]
+    [TestCase("1. i\n\t1. i\n2. i")]
+    public void TestMultipleLevels(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("1.     c")]
+    [TestCase("1.      c")]
+    public void Test_IndentedCodeBlock(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestParagraph.cs

@@ -0,0 +1,245 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestParagraph
+{
+    [TestCase("p")]
+    [TestCase(" p")]
+    [TestCase("p ")]
+    [TestCase(" p ")]
+
+    [TestCase("p\np")]
+    [TestCase(" p\np")]
+    [TestCase("p \np")]
+    [TestCase(" p \np")]
+
+    [TestCase("p\n p")]
+    [TestCase(" p\n p")]
+    [TestCase("p \n p")]
+    [TestCase(" p \n p")]
+
+    [TestCase("p\np ")]
+    [TestCase(" p\np ")]
+    [TestCase("p \np ")]
+    [TestCase(" p \np ")]
+
+    [TestCase("p\n\n p ")]
+    [TestCase(" p\n\n p ")]
+    [TestCase("p \n\n p ")]
+    [TestCase(" p \n\n p ")]
+
+    [TestCase("p\n\np")]
+    [TestCase(" p\n\np")]
+    [TestCase("p \n\np")]
+    [TestCase(" p \n\np")]
+
+    [TestCase("p\n\n p")]
+    [TestCase(" p\n\n p")]
+    [TestCase("p \n\n p")]
+    [TestCase(" p \n\n p")]
+
+    [TestCase("p\n\np ")]
+    [TestCase(" p\n\np ")]
+    [TestCase("p \n\np ")]
+    [TestCase(" p \n\np ")]
+
+    [TestCase("p\n\n p ")]
+    [TestCase(" p\n\n p ")]
+    [TestCase("p \n\n p ")]
+    [TestCase(" p \n\n p ")]
+
+    [TestCase("\np")]
+    [TestCase("\n p")]
+    [TestCase("\np ")]
+    [TestCase("\n p ")]
+
+    [TestCase("\np\np")]
+    [TestCase("\n p\np")]
+    [TestCase("\np \np")]
+    [TestCase("\n p \np")]
+
+    [TestCase("\np\n p")]
+    [TestCase("\n p\n p")]
+    [TestCase("\np \n p")]
+    [TestCase("\n p \n p")]
+
+    [TestCase("\np\np ")]
+    [TestCase("\n p\np ")]
+    [TestCase("\np \np ")]
+    [TestCase("\n p \np ")]
+
+    [TestCase("\np\n\n p ")]
+    [TestCase("\n p\n\n p ")]
+    [TestCase("\np \n\n p ")]
+    [TestCase("\n p \n\n p ")]
+
+    [TestCase("\np\n\np")]
+    [TestCase("\n p\n\np")]
+    [TestCase("\np \n\np")]
+    [TestCase("\n p \n\np")]
+
+    [TestCase("\np\n\n p")]
+    [TestCase("\n p\n\n p")]
+    [TestCase("\np \n\n p")]
+    [TestCase("\n p \n\n p")]
+
+    [TestCase("\np\n\np ")]
+    [TestCase("\n p\n\np ")]
+    [TestCase("\np \n\np ")]
+    [TestCase("\n p \n\np ")]
+
+    [TestCase("\np\n\n p ")]
+    [TestCase("\n p\n\n p ")]
+    [TestCase("\np \n\n p ")]
+    [TestCase("\n p \n\n p ")]
+
+    [TestCase("p  p")]
+    [TestCase("p\tp")]
+    [TestCase("p \tp")]
+    [TestCase("p \t p")]
+    [TestCase("p \tp")]
+
+    // special cases
+    [TestCase(" p \n\n\n\n p \n\n")]
+    [TestCase("\n\np")]
+    [TestCase("p\n")]
+    [TestCase("p\n\n")]
+    [TestCase("p\np\n p")]
+    [TestCase("p\np\n p\n p")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+
+    [TestCase("\n")]
+    [TestCase("\r\n")]
+    [TestCase("\r")]
+
+    [TestCase("p\n")]
+    [TestCase("p\r")]
+    [TestCase("p\r\n")]
+
+    [TestCase("p\np")]
+    [TestCase("p\rp")]
+    [TestCase("p\r\np")]
+
+    [TestCase("p\np\n")]
+    [TestCase("p\rp\n")]
+    [TestCase("p\r\np\n")]
+
+    [TestCase("p\np\r")]
+    [TestCase("p\rp\r")]
+    [TestCase("p\r\np\r")]
+
+    [TestCase("p\np\r\n")]
+    [TestCase("p\rp\r\n")]
+    [TestCase("p\r\np\r\n")]
+
+    [TestCase("\np\n")]
+    [TestCase("\np\r")]
+    [TestCase("\np\r\n")]
+
+    [TestCase("\np\np")]
+    [TestCase("\np\rp")]
+    [TestCase("\np\r\np")]
+
+    [TestCase("\np\np\n")]
+    [TestCase("\np\rp\n")]
+    [TestCase("\np\r\np\n")]
+
+    [TestCase("\np\np\r")]
+    [TestCase("\np\rp\r")]
+    [TestCase("\np\r\np\r")]
+
+    [TestCase("\np\np\r\n")]
+    [TestCase("\np\rp\r\n")]
+    [TestCase("\np\r\np\r\n")]
+
+    [TestCase("\rp\n")]
+    [TestCase("\rp\r")]
+    [TestCase("\rp\r\n")]
+
+    [TestCase("\rp\np")]
+    [TestCase("\rp\rp")]
+    [TestCase("\rp\r\np")]
+
+    [TestCase("\rp\np\n")]
+    [TestCase("\rp\rp\n")]
+    [TestCase("\rp\r\np\n")]
+
+    [TestCase("\rp\np\r")]
+    [TestCase("\rp\rp\r")]
+    [TestCase("\rp\r\np\r")]
+
+    [TestCase("\rp\np\r\n")]
+    [TestCase("\rp\rp\r\n")]
+    [TestCase("\rp\r\np\r\n")]
+
+    [TestCase("\r\np\n")]
+    [TestCase("\r\np\r")]
+    [TestCase("\r\np\r\n")]
+
+    [TestCase("\r\np\np")]
+    [TestCase("\r\np\rp")]
+    [TestCase("\r\np\r\np")]
+
+    [TestCase("\r\np\np\n")]
+    [TestCase("\r\np\rp\n")]
+    [TestCase("\r\np\r\np\n")]
+
+    [TestCase("\r\np\np\r")]
+    [TestCase("\r\np\rp\r")]
+    [TestCase("\r\np\r\np\r")]
+
+    [TestCase("\r\np\np\r\n")]
+    [TestCase("\r\np\rp\r\n")]
+    [TestCase("\r\np\r\np\r\n")]
+
+    [TestCase("p\n")]
+    [TestCase("p\n\n")]
+    [TestCase("p\n\n\n")]
+    [TestCase("p\n\n\n\n")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase(" \n")]
+    [TestCase(" \r")]
+    [TestCase(" \r\n")]
+
+    [TestCase(" \np")]
+    [TestCase(" \rp")]
+    [TestCase(" \r\np")]
+
+    [TestCase("  \np")]
+    [TestCase("  \rp")]
+    [TestCase("  \r\np")]
+
+    [TestCase("   \np")]
+    [TestCase("   \rp")]
+    [TestCase("   \r\np")]
+
+    [TestCase(" \n ")]
+    [TestCase(" \r ")]
+    [TestCase(" \r\n ")]
+
+    [TestCase(" \np ")]
+    [TestCase(" \rp ")]
+    [TestCase(" \r\np ")]
+
+    [TestCase("  \np ")]
+    [TestCase("  \rp ")]
+    [TestCase("  \r\np ")]
+
+    [TestCase("   \np ")]
+    [TestCase("   \rp ")]
+    [TestCase("   \r\np ")]
+    public void Test_WhitespaceWithNewline(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestQuoteBlock.cs

@@ -0,0 +1,284 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestQuoteBlock
+{
+    [TestCase(">q")]
+    [TestCase(" >q")]
+    [TestCase("  >q")]
+    [TestCase("   >q")]
+    [TestCase("> q")]
+    [TestCase(" > q")]
+    [TestCase("  > q")]
+    [TestCase("   > q")]
+    [TestCase(">  q")]
+    [TestCase(" >  q")]
+    [TestCase("  >  q")]
+    [TestCase("   >  q")]
+
+    [TestCase(">q\n>q")]
+    [TestCase(">q\n >q")]
+    [TestCase(">q\n  >q")]
+    [TestCase(">q\n   >q")]
+    [TestCase(">q\n> q")]
+    [TestCase(">q\n > q")]
+    [TestCase(">q\n  > q")]
+    [TestCase(">q\n   > q")]
+    [TestCase(">q\n>  q")]
+    [TestCase(">q\n >  q")]
+    [TestCase(">q\n  >  q")]
+    [TestCase(">q\n   >  q")]
+
+    [TestCase(" >q\n>q")]
+    [TestCase(" >q\n >q")]
+    [TestCase(" >q\n  >q")]
+    [TestCase(" >q\n   >q")]
+    [TestCase(" >q\n> q")]
+    [TestCase(" >q\n > q")]
+    [TestCase(" >q\n  > q")]
+    [TestCase(" >q\n   > q")]
+    [TestCase(" >q\n>  q")]
+    [TestCase(" >q\n >  q")]
+    [TestCase(" >q\n  >  q")]
+    [TestCase(" >q\n   >  q")]
+
+    [TestCase("  >q\n>q")]
+    [TestCase("  >q\n >q")]
+    [TestCase("  >q\n  >q")]
+    [TestCase("  >q\n   >q")]
+    [TestCase("  >q\n> q")]
+    [TestCase("  >q\n > q")]
+    [TestCase("  >q\n  > q")]
+    [TestCase("  >q\n   > q")]
+    [TestCase("  >q\n>  q")]
+    [TestCase("  >q\n >  q")]
+    [TestCase("  >q\n  >  q")]
+    [TestCase("  >q\n   >  q")]
+
+    [TestCase("> q\n>q")]
+    [TestCase("> q\n >q")]
+    [TestCase("> q\n  >q")]
+    [TestCase("> q\n   >q")]
+    [TestCase("> q\n> q")]
+    [TestCase("> q\n > q")]
+    [TestCase("> q\n  > q")]
+    [TestCase("> q\n   > q")]
+    [TestCase("> q\n>  q")]
+    [TestCase("> q\n >  q")]
+    [TestCase("> q\n  >  q")]
+    [TestCase("> q\n   >  q")]
+
+    [TestCase(" > q\n>q")]
+    [TestCase(" > q\n >q")]
+    [TestCase(" > q\n  >q")]
+    [TestCase(" > q\n   >q")]
+    [TestCase(" > q\n> q")]
+    [TestCase(" > q\n > q")]
+    [TestCase(" > q\n  > q")]
+    [TestCase(" > q\n   > q")]
+    [TestCase(" > q\n>  q")]
+    [TestCase(" > q\n >  q")]
+    [TestCase(" > q\n  >  q")]
+    [TestCase(" > q\n   >  q")]
+
+    [TestCase("  > q\n>q")]
+    [TestCase("  > q\n >q")]
+    [TestCase("  > q\n  >q")]
+    [TestCase("  > q\n   >q")]
+    [TestCase("  > q\n> q")]
+    [TestCase("  > q\n > q")]
+    [TestCase("  > q\n  > q")]
+    [TestCase("  > q\n   > q")]
+    [TestCase("  > q\n>  q")]
+    [TestCase("  > q\n >  q")]
+    [TestCase("  > q\n  >  q")]
+    [TestCase("  > q\n   >  q")]
+
+    [TestCase("   > q\n>q")]
+    [TestCase("   > q\n >q")]
+    [TestCase("   > q\n  >q")]
+    [TestCase("   > q\n   >q")]
+    [TestCase("   > q\n> q")]
+    [TestCase("   > q\n > q")]
+    [TestCase("   > q\n  > q")]
+    [TestCase("   > q\n   > q")]
+    [TestCase("   > q\n>  q")]
+    [TestCase("   > q\n >  q")]
+    [TestCase("   > q\n  >  q")]
+    [TestCase("   > q\n   >  q")]
+
+    [TestCase(">  q\n>q")]
+    [TestCase(">  q\n >q")]
+    [TestCase(">  q\n  >q")]
+    [TestCase(">  q\n   >q")]
+    [TestCase(">  q\n> q")]
+    [TestCase(">  q\n > q")]
+    [TestCase(">  q\n  > q")]
+    [TestCase(">  q\n   > q")]
+    [TestCase(">  q\n>  q")]
+    [TestCase(">  q\n >  q")]
+    [TestCase(">  q\n  >  q")]
+    [TestCase(">  q\n   >  q")]
+
+    [TestCase(" >  q\n>q")]
+    [TestCase(" >  q\n >q")]
+    [TestCase(" >  q\n  >q")]
+    [TestCase(" >  q\n   >q")]
+    [TestCase(" >  q\n> q")]
+    [TestCase(" >  q\n > q")]
+    [TestCase(" >  q\n  > q")]
+    [TestCase(" >  q\n   > q")]
+    [TestCase(" >  q\n>  q")]
+    [TestCase(" >  q\n >  q")]
+    [TestCase(" >  q\n  >  q")]
+    [TestCase(" >  q\n   >  q")]
+
+    [TestCase("  >  q\n>q")]
+    [TestCase("  >  q\n >q")]
+    [TestCase("  >  q\n  >q")]
+    [TestCase("  >  q\n   >q")]
+    [TestCase("  >  q\n> q")]
+    [TestCase("  >  q\n > q")]
+    [TestCase("  >  q\n  > q")]
+    [TestCase("  >  q\n   > q")]
+    [TestCase("  >  q\n>  q")]
+    [TestCase("  >  q\n >  q")]
+    [TestCase("  >  q\n  >  q")]
+    [TestCase("  >  q\n   >  q")]
+
+    [TestCase("   >  q\n>q")]
+    [TestCase("   >  q\n >q")]
+    [TestCase("   >  q\n  >q")]
+    [TestCase("   >  q\n   >q")]
+    [TestCase("   >  q\n> q")]
+    [TestCase("   >  q\n > q")]
+    [TestCase("   >  q\n  > q")]
+    [TestCase("   >  q\n   > q")]
+    [TestCase("   >  q\n>  q")]
+    [TestCase("   >  q\n >  q")]
+    [TestCase("   >  q\n  >  q")]
+    [TestCase("   >  q\n   >  q")]
+
+    [TestCase(">q\n>q\n>q")]
+    [TestCase(">q\n>\n>q")]
+    [TestCase(">q\np\n>q")]
+    [TestCase(">q\n>\n>\n>q")]
+    [TestCase(">q\n>\n>\n>\n>q")]
+    [TestCase(">q\n>\n>q\n>\n>q")]
+    [TestCase("p\n\n> **q**\n>p\n")]
+
+    [TestCase("> q\np\n> q")] // lazy
+    [TestCase("> q\n> q\np")] // lazy
+
+    [TestCase(">>q")]
+    [TestCase(" >  >   q")]
+
+    [TestCase("> **q**\n>p\n")]
+    [TestCase("> **q**")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase(">     q")] // 5
+    [TestCase(">      q")] // 6
+    [TestCase(" >     q")] //5
+    [TestCase(" >      q")] //6
+    [TestCase(" > \tq")]
+    [TestCase(">     q\n>     q")] // 5, 5
+    [TestCase(">     q\n>      q")] // 5, 6
+    [TestCase(">      q\n>     q")] // 6, 5
+    [TestCase(">      q\n>      q")] // 6, 6
+    [TestCase(">     q\n\n>     5")] // 5, 5
+    public void TestIndentedCodeBlock(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("\n> q")]
+    [TestCase("\n> q\n")]
+    [TestCase("\n> q\n\n")]
+    [TestCase("> q\n\np")]
+    [TestCase("p\n\n> q\n\n# h")]
+
+    //https://github.com/lunet-io/markdig/issues/480
+    //[TestCase(">\np")]
+    //[TestCase(">**b**\n>\n>p\n>\np\n")]
+    public void TestParagraph(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("> q\n\n# h\n")]
+    public void TestAtxHeader(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase(">- i")]
+    [TestCase("> - i")]
+    [TestCase(">- i\n>- i")]
+    [TestCase(">- >p")]
+    [TestCase("> - >p")]
+    [TestCase(">- i1\n>- i2\n")]
+    [TestCase("> **p** p\n>- i1\n>- i2\n")]
+    public void TestUnorderedList(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("> *q*\n>p\n")]
+    [TestCase("> *q*")]
+    public void TestEmphasis(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("> **q**\n>p\n")]
+    [TestCase("> **q**")]
+    public void TestStrongEmphasis(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase(">p\n")]
+    [TestCase(">p\r")]
+    [TestCase(">p\r\n")]
+
+    [TestCase(">p\n>p")]
+    [TestCase(">p\r>p")]
+    [TestCase(">p\r\n>p")]
+
+    [TestCase(">p\n>p\n")]
+    [TestCase(">p\r>p\n")]
+    [TestCase(">p\r\n>p\n")]
+
+    [TestCase(">p\n>p\r")]
+    [TestCase(">p\r>p\r")]
+    [TestCase(">p\r\n>p\r")]
+
+    [TestCase(">p\n>p\r\n")]
+    [TestCase(">p\r>p\r\n")]
+    [TestCase(">p\r\n>p\r\n")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase(">\n>q")]
+    [TestCase(">\n>\n>q")]
+    [TestCase(">q\n>\n>q")]
+    [TestCase(">q\n>\n>\n>q")]
+    [TestCase(">q\n> \n>q")]
+    [TestCase(">q\n>  \n>q")]
+    [TestCase(">q\n>   \n>q")]
+    [TestCase(">q\n>\t\n>q")]
+    [TestCase(">q\n>\v\n>q")]
+    [TestCase(">q\n>\f\n>q")]
+    public void TestEmptyLines(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestSetextHeading.cs

@@ -0,0 +1,51 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestSetextHeading
+{
+    [TestCase("h1\n===")] //3
+    [TestCase("h1\n ===")] //3
+    [TestCase("h1\n  ===")] //3
+    [TestCase("h1\n   ===")] //3
+    [TestCase("h1\n=== ")] //3
+    [TestCase("h1 \n===")] //3
+    [TestCase("h1\\\n===")] //3
+    [TestCase("h1\n === ")] //3
+    [TestCase("h1\nh1 l2\n===")] //3
+    [TestCase("h1\n====")] // 4
+    [TestCase("h1\n ====")] // 4
+    [TestCase("h1\n==== ")] // 4
+    [TestCase("h1\n ==== ")] // 4
+    [TestCase("h1\n===\nh1\n===")] //3
+    [TestCase("\\>h1\n===")] //3
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("h1\r===")]
+    [TestCase("h1\n===")]
+    [TestCase("h1\r\n===")]
+
+    [TestCase("h1\r===\r")]
+    [TestCase("h1\n===\r")]
+    [TestCase("h1\r\n===\r")]
+
+    [TestCase("h1\r===\n")]
+    [TestCase("h1\n===\n")]
+    [TestCase("h1\r\n===\n")]
+
+    [TestCase("h1\r===\r\n")]
+    [TestCase("h1\n===\r\n")]
+    [TestCase("h1\r\n===\r\n")]
+
+    [TestCase("h1\n===\n\n\nh2---\n\n")]
+    [TestCase("h1\r===\r\r\rh2---\r\r")]
+    [TestCase("h1\r\n===\r\n\r\n\r\nh2---\r\n\r\n")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestThematicBreak.cs

@@ -0,0 +1,51 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestThematicBreak
+{
+    [TestCase("---")]
+    [TestCase(" ---")]
+    [TestCase("  ---")]
+    [TestCase("   ---")]
+    [TestCase("--- ")]
+    [TestCase(" --- ")]
+    [TestCase("  --- ")]
+    [TestCase("   --- ")]
+    [TestCase("- - -")]
+    [TestCase(" - - -")]
+    [TestCase(" - - - ")]
+    [TestCase("-- -")]
+    [TestCase("---\n")]
+    [TestCase("---\n\n")]
+    [TestCase("---\np")]
+    [TestCase("---\n\np")]
+    [TestCase("---\n# h")]
+    [TestCase("p\n\n---")]
+    // Note: "p\n---" is parsed as setext heading
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("\n---")]
+    [TestCase("\r---")]
+    [TestCase("\r\n---")]
+
+    [TestCase("\n---\n")]
+    [TestCase("\r---\n")]
+    [TestCase("\r\n---\n")]
+
+    [TestCase("\n---\r")]
+    [TestCase("\r---\r")]
+    [TestCase("\r\n---\r")]
+
+    [TestCase("\n---\r\n")]
+    [TestCase("\r---\r\n")]
+    [TestCase("\r\n---\r\n")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestUnorderedList.cs

@@ -0,0 +1,182 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestUnorderedList
+{
+    // i = item
+    [TestCase("- i1")]
+    [TestCase("- i1 ")]
+    [TestCase("- i1\n")]
+    [TestCase("- i1\n\n")]
+    [TestCase("- i1\n- i2")]
+    [TestCase("- i1\n    - i2")]
+    [TestCase("- i1\n    - i1.1\n    - i1.2")]
+    [TestCase("- i1 \n- i2 \n")]
+    [TestCase("- i1  \n- i2  \n")]
+    [TestCase(" - i1")]
+    [TestCase("  - i1")]
+    [TestCase("   - i1")]
+    [TestCase("- i1\n\n- i1")]
+    [TestCase("- i1\n\n\n- i1")]
+    [TestCase("- i1\n    - i1.1\n        - i1.1.1\n")]
+
+    [TestCase("-\ti1")]
+    [TestCase("-\ti1\n-\ti2")]
+    [TestCase("-\ti1\n-  i2\n-\ti3")]
+    [TestCase("- 1.\n- 2.")]
+    public void Test(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("- > q")]
+    [TestCase(" - > q")]
+    [TestCase("  - > q")]
+    [TestCase("   - > q")]
+    [TestCase("-  > q")]
+    [TestCase(" -  > q")]
+    [TestCase("  -  > q")]
+    [TestCase("   -  > q")]
+    [TestCase("-   > q")]
+    [TestCase(" -   > q")]
+    [TestCase("  -   > q")]
+    [TestCase("   -   > q")]
+    [TestCase("-    > q")]
+    [TestCase(" -    > q")]
+    [TestCase("  -    > q")]
+    [TestCase("   -    > q")]
+    [TestCase("   -    > q1\n   -    > q2")]
+    public void TestBlockQuote(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("-     i1\n\np\n")] // TODO: listblock should render newline, apparently last paragraph of last listitem dont have newline
+    [TestCase("-     i1\n\n\np\n")]
+    [TestCase("- i1\n\np")]
+    [TestCase("- i1\n\np\n")]
+    public void TestParagraph(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("- i1\n\n---\n")]
+    [TestCase("- i1\n\n\n---\n")]
+    public void TestThematicBreak(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("-     c")] // 5
+    [TestCase("-     c\n      c")] // 5, 6
+    [TestCase(" -     c\n      c")] // 5, 6
+    [TestCase(" -     c\n       c")] // 5, 7
+    [TestCase("-      c\n      c")] // 6, 6
+    [TestCase(" -      c\n      c")] // 6, 6
+    [TestCase(" -      c\n       c")] // 6, 7
+    public void TestIndentedCodeBlock(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("- ```a```")]
+    [TestCase("- ```\n  a\n```")]
+    [TestCase("- i1\n    - i1.1\n    ```\n    c\n    ```")]
+    [TestCase("- i1\n    - i1.1\n    ```\nc\n```")]
+    [TestCase("- i1\n    - i1.1\n    ```\nc\n```\n")]
+    public void TestFencedCodeBlock(string value)
+    {
+        RoundTrip(value);
+    }
+
+    [TestCase("\n- i")]
+    [TestCase("\r- i")]
+    [TestCase("\r\n- i")]
+
+    [TestCase("\n- i\n")]
+    [TestCase("\r- i\n")]
+    [TestCase("\r\n- i\n")]
+
+    [TestCase("\n- i\r")]
+    [TestCase("\r- i\r")]
+    [TestCase("\r\n- i\r")]
+
+    [TestCase("\n- i\r\n")]
+    [TestCase("\r- i\r\n")]
+    [TestCase("\r\n- i\r\n")]
+
+    [TestCase("- i\n- j")]
+    [TestCase("- i\r- j")]
+    [TestCase("- i\r\n- j")]
+
+    [TestCase("\n- i\n- j")]
+    [TestCase("\n- i\r- j")]
+    [TestCase("\n- i\r\n- j")]
+
+    [TestCase("\r- i\n- j")]
+    [TestCase("\r- i\r- j")]
+    [TestCase("\r- i\r\n- j")]
+
+    [TestCase("\r\n- i\n- j")]
+    [TestCase("\r\n- i\r- j")]
+    [TestCase("\r\n- i\r\n- j")]
+
+    [TestCase("- i\n- j\n")]
+    [TestCase("- i\r- j\n")]
+    [TestCase("- i\r\n- j\n")]
+
+    [TestCase("\n- i\n- j\n")]
+    [TestCase("\n- i\r- j\n")]
+    [TestCase("\n- i\r\n- j\n")]
+
+    [TestCase("\r- i\n- j\n")]
+    [TestCase("\r- i\r- j\n")]
+    [TestCase("\r- i\r\n- j\n")]
+
+    [TestCase("\r\n- i\n- j\n")]
+    [TestCase("\r\n- i\r- j\n")]
+    [TestCase("\r\n- i\r\n- j\n")]
+
+    [TestCase("- i\n- j\r")]
+    [TestCase("- i\r- j\r")]
+    [TestCase("- i\r\n- j\r")]
+
+    [TestCase("\n- i\n- j\r")]
+    [TestCase("\n- i\r- j\r")]
+    [TestCase("\n- i\r\n- j\r")]
+
+    [TestCase("\r- i\n- j\r")]
+    [TestCase("\r- i\r- j\r")]
+    [TestCase("\r- i\r\n- j\r")]
+
+    [TestCase("\r\n- i\n- j\r")]
+    [TestCase("\r\n- i\r- j\r")]
+    [TestCase("\r\n- i\r\n- j\r")]
+
+    [TestCase("- i\n- j\r\n")]
+    [TestCase("- i\r- j\r\n")]
+    [TestCase("- i\r\n- j\r\n")]
+
+    [TestCase("\n- i\n- j\r\n")]
+    [TestCase("\n- i\r- j\r\n")]
+    [TestCase("\n- i\r\n- j\r\n")]
+
+    [TestCase("\r- i\n- j\r\n")]
+    [TestCase("\r- i\r- j\r\n")]
+    [TestCase("\r- i\r\n- j\r\n")]
+
+    [TestCase("\r\n- i\n- j\r\n")]
+    [TestCase("\r\n- i\r- j\r\n")]
+    [TestCase("\r\n- i\r\n- j\r\n")]
+
+    [TestCase("- i\n")]
+    [TestCase("- i\n\n")]
+    [TestCase("- i\n\n\n")]
+    [TestCase("- i\n\n\n\n")]
+    public void TestNewline(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/RoundtripSpecs/TestYamlFrontMatterBlock.cs

@@ -0,0 +1,15 @@
+using static Markdig.Tests.TestRoundtrip;
+
+namespace Markdig.Tests.RoundtripSpecs;
+
+[TestFixture]
+public class TestYamlFrontMatterBlock
+{
+    [TestCase("---\nkey1: value1\nkey2: value2\n---\n\nContent\n")]
+    [TestCase("No front matter")]
+    [TestCase("Looks like front matter but actually is not\n---\nkey1: value1\nkey2: value2\n---")]
+    public void FrontMatterBlockIsPreserved(string value)
+    {
+        RoundTrip(value);
+    }
+}

src/Markdig.Tests/Specs/AbbreviationSpecs.generated.cs

@@ -0,0 +1,224 @@
+
+// --------------------------------
+//           Abbreviations
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.Abbreviations
+{
+    [TestFixture]
+    public class TestExtensionsAbbreviation
+    {
+        // # Extensions
+        // 
+        // This section describes the different extensions supported:
+        // 
+        // ## Abbreviation
+        // 
+        // Abbreviation can be declared by using the `*[Abbreviation Label]: Abbreviation description`
+        // 
+        // Abbreviation definition will be removed from the original document. Any Abbreviation label found in literals will be replaced by the abbreviation description:
+        [Test]
+        public void ExtensionsAbbreviation_Example001()
+        {
+            // Example 1
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[HTML]: Hypertext Markup Language
+            //     
+            //     Later in a text we are using HTML and it becomes an abbr tag HTML
+            //
+            // Should be rendered as:
+            //     <p>Later in a text we are using <abbr title="Hypertext Markup Language">HTML</abbr> and it becomes an abbr tag <abbr title="Hypertext Markup Language">HTML</abbr></p>
+
+            TestParser.TestSpec("*[HTML]: Hypertext Markup Language\n\nLater in a text we are using HTML and it becomes an abbr tag HTML", "<p>Later in a text we are using <abbr title=\"Hypertext Markup Language\">HTML</abbr> and it becomes an abbr tag <abbr title=\"Hypertext Markup Language\">HTML</abbr></p>", "abbreviations|advanced", context: "Example 1\nSection Extensions / Abbreviation\n");
+        }
+
+        // An abbreviation definition can be indented at most 3 spaces
+        [Test]
+        public void ExtensionsAbbreviation_Example002()
+        {
+            // Example 2
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[HTML]: Hypertext Markup Language
+            //         *[This]: is not an abbreviation
+            //
+            // Should be rendered as:
+            //     <pre><code>*[This]: is not an abbreviation
+            //     </code></pre>
+
+            TestParser.TestSpec("*[HTML]: Hypertext Markup Language\n    *[This]: is not an abbreviation", "<pre><code>*[This]: is not an abbreviation\n</code></pre>", "abbreviations|advanced", context: "Example 2\nSection Extensions / Abbreviation\n");
+        }
+
+        // An abbreviation may contain spaces:
+        [Test]
+        public void ExtensionsAbbreviation_Example003()
+        {
+            // Example 3
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[SUPER HTML]: Super Hypertext Markup Language
+            //     
+            //     This is a SUPER HTML document    
+            //
+            // Should be rendered as:
+            //     <p>This is a <abbr title="Super Hypertext Markup Language">SUPER HTML</abbr> document</p>
+
+            TestParser.TestSpec("*[SUPER HTML]: Super Hypertext Markup Language\n\nThis is a SUPER HTML document    ", "<p>This is a <abbr title=\"Super Hypertext Markup Language\">SUPER HTML</abbr> document</p>", "abbreviations|advanced", context: "Example 3\nSection Extensions / Abbreviation\n");
+        }
+
+        // Abbreviation may contain any unicode characters:
+        [Test]
+        public void ExtensionsAbbreviation_Example004()
+        {
+            // Example 4
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[😃 HTML]: Hypertext Markup Language
+            //     
+            //     This is a 😃 HTML document    
+            //
+            // Should be rendered as:
+            //     <p>This is a <abbr title="Hypertext Markup Language">😃 HTML</abbr> document</p>
+
+            TestParser.TestSpec("*[😃 HTML]: Hypertext Markup Language\n\nThis is a 😃 HTML document    ", "<p>This is a <abbr title=\"Hypertext Markup Language\">😃 HTML</abbr> document</p>", "abbreviations|advanced", context: "Example 4\nSection Extensions / Abbreviation\n");
+        }
+
+        // Abbreviations may be similar:
+        [Test]
+        public void ExtensionsAbbreviation_Example005()
+        {
+            // Example 5
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[1A]: First
+            //     *[1A1]: Second
+            //     *[1A2]: Third
+            //     
+            //     We can abbreviate 1A, 1A1 and 1A2!
+            //
+            // Should be rendered as:
+            //     <p>We can abbreviate <abbr title="First">1A</abbr>, <abbr title="Second">1A1</abbr> and <abbr title="Third">1A2</abbr>!</p>
+
+            TestParser.TestSpec("*[1A]: First\n*[1A1]: Second\n*[1A2]: Third\n\nWe can abbreviate 1A, 1A1 and 1A2!", "<p>We can abbreviate <abbr title=\"First\">1A</abbr>, <abbr title=\"Second\">1A1</abbr> and <abbr title=\"Third\">1A2</abbr>!</p>", "abbreviations|advanced", context: "Example 5\nSection Extensions / Abbreviation\n");
+        }
+
+        // Abbreviations should match whole word only:
+        [Test]
+        public void ExtensionsAbbreviation_Example006()
+        {
+            // Example 6
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[1A]: First
+            //     
+            //     We should not abbreviate 1.1A or 11A!
+            //
+            // Should be rendered as:
+            //     <p>We should not abbreviate 1.1A or 11A!</p>
+
+            TestParser.TestSpec("*[1A]: First\n\nWe should not abbreviate 1.1A or 11A!", "<p>We should not abbreviate 1.1A or 11A!</p>", "abbreviations|advanced", context: "Example 6\nSection Extensions / Abbreviation\n");
+        }
+
+        // Abbreviations should match whole word only, even if the word is the entire content:
+        [Test]
+        public void ExtensionsAbbreviation_Example007()
+        {
+            // Example 7
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[1A]: First
+            //     
+            //     1.1A
+            //
+            // Should be rendered as:
+            //     <p>1.1A</p>
+
+            TestParser.TestSpec("*[1A]: First\n\n1.1A", "<p>1.1A</p>", "abbreviations|advanced", context: "Example 7\nSection Extensions / Abbreviation\n");
+        }
+
+        // Abbreviations should match whole word only, even if there is another glossary term:
+        [Test]
+        public void ExtensionsAbbreviation_Example008()
+        {
+            // Example 8
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[SCO]: First
+            //     *[SCOM]: Second
+            //     
+            //     SCOM
+            //
+            // Should be rendered as:
+            //     <p><abbr title="Second">SCOM</abbr></p>
+
+            TestParser.TestSpec("*[SCO]: First\n*[SCOM]: Second\n\nSCOM", "<p><abbr title=\"Second\">SCOM</abbr></p>", "abbreviations|advanced", context: "Example 8\nSection Extensions / Abbreviation\n");
+        }
+
+        // Abbreviations should only match when surrounded by whitespace:
+        [Test]
+        public void ExtensionsAbbreviation_Example009()
+        {
+            // Example 9
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[PR]: Pull Request
+            //     
+            //     PRAA
+            //
+            // Should be rendered as:
+            //     <p>PRAA</p>
+
+            TestParser.TestSpec("*[PR]: Pull Request\n\nPRAA", "<p>PRAA</p>", "abbreviations|advanced", context: "Example 9\nSection Extensions / Abbreviation\n");
+        }
+
+        // Single character abbreviations should be matched
+        [Test]
+        public void ExtensionsAbbreviation_Example010()
+        {
+            // Example 10
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[A]: Foo
+            //     
+            //     A
+            //
+            // Should be rendered as:
+            //     <p><abbr title="Foo">A</abbr></p>
+
+            TestParser.TestSpec("*[A]: Foo\n\nA", "<p><abbr title=\"Foo\">A</abbr></p>", "abbreviations|advanced", context: "Example 10\nSection Extensions / Abbreviation\n");
+        }
+
+        // The longest matching abbreviation should be used
+        [Test]
+        public void ExtensionsAbbreviation_Example011()
+        {
+            // Example 11
+            // Section: Extensions / Abbreviation
+            //
+            // The following Markdown:
+            //     *[Foo]: foo
+            //     *[Foo Bar]: foobar
+            //     
+            //     Foo B
+            //
+            // Should be rendered as:
+            //     <p><abbr title="foo">Foo</abbr> B</p>
+
+            TestParser.TestSpec("*[Foo]: foo\n*[Foo Bar]: foobar\n\nFoo B", "<p><abbr title=\"foo\">Foo</abbr> B</p>", "abbreviations|advanced", context: "Example 11\nSection Extensions / Abbreviation\n");
+        }
+    }
+}

src/Markdig.Tests/Specs/AbbreviationSpecs.md

@@ -45,3 +45,77 @@ This is a 😃 HTML document
 .
 <p>This is a <abbr title="Hypertext Markup Language">😃 HTML</abbr> document</p>
 ````````````````````````````````
+
+Abbreviations may be similar:
+
+```````````````````````````````` example
+*[1A]: First
+*[1A1]: Second
+*[1A2]: Third
+
+We can abbreviate 1A, 1A1 and 1A2!
+.
+<p>We can abbreviate <abbr title="First">1A</abbr>, <abbr title="Second">1A1</abbr> and <abbr title="Third">1A2</abbr>!</p>
+````````````````````````````````
+
+Abbreviations should match whole word only:
+
+```````````````````````````````` example
+*[1A]: First
+
+We should not abbreviate 1.1A or 11A!
+.
+<p>We should not abbreviate 1.1A or 11A!</p>
+````````````````````````````````
+
+Abbreviations should match whole word only, even if the word is the entire content:
+
+```````````````````````````````` example
+*[1A]: First
+
+1.1A
+.
+<p>1.1A</p>
+````````````````````````````````
+
+Abbreviations should match whole word only, even if there is another glossary term:
+
+```````````````````````````````` example
+*[SCO]: First
+*[SCOM]: Second
+
+SCOM
+.
+<p><abbr title="Second">SCOM</abbr></p>
+````````````````````````````````
+
+Abbreviations should only match when surrounded by whitespace:
+
+```````````````````````````````` example
+*[PR]: Pull Request
+
+PRAA
+.
+<p>PRAA</p>
+````````````````````````````````
+
+Single character abbreviations should be matched
+
+```````````````````````````````` example
+*[A]: Foo
+
+A
+.
+<p><abbr title="Foo">A</abbr></p>
+````````````````````````````````
+
+The longest matching abbreviation should be used
+
+```````````````````````````````` example
+*[Foo]: foo
+*[Foo Bar]: foobar
+
+Foo B
+.
+<p><abbr title="foo">Foo</abbr> B</p>
+````````````````````````````````

src/Markdig.Tests/Specs/AlertBlockSpecs.generated.cs

@@ -0,0 +1,179 @@
+
+// --------------------------------
+//           Alert Blocks
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.AlertBlocks
+{
+    [TestFixture]
+    public class TestExtensionsAlertBlocks
+    {
+        // # Extensions
+        // 
+        // This section describes the different extensions supported:
+        // 
+        // ## Alert Blocks
+        // 
+        // This is supporting the [GitHub Alert blocks](https://github.com/orgs/community/discussions/16925)
+        [Test]
+        public void ExtensionsAlertBlocks_Example001()
+        {
+            // Example 1
+            // Section: Extensions / Alert Blocks
+            //
+            // The following Markdown:
+            //     > [!NOTE]  
+            //     > Highlights information that users should take into account, even when skimming.
+            //     
+            //     > [!TIP]
+            //     > Optional information to help a user be more successful.
+            //     
+            //     > [!IMPORTANT]  
+            //     > Crucial information necessary for users to succeed.
+            //     
+            //     > [!WARNING]  
+            //     > Critical content demanding immediate user attention due to potential risks.
+            //     
+            //     > [!CAUTION]
+            //     > Negative potential consequences of an action.
+            //
+            // Should be rendered as:
+            //     <div class="markdown-alert markdown-alert-note">
+            //     <p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Note</p>
+            //     <p>Highlights information that users should take into account, even when skimming.</p>
+            //     </div>
+            //     <div class="markdown-alert markdown-alert-tip">
+            //     <p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M8 1.5c-2.363 0-4 1.69-4 3.75 0 .984.424 1.625.984 2.304l.214.253c.223.264.47.556.673.848.284.411.537.896.621 1.49a.75.75 0 0 1-1.484.211c-.04-.282-.163-.547-.37-.847a8.456 8.456 0 0 0-.542-.68c-.084-.1-.173-.205-.268-.32C3.201 7.75 2.5 6.766 2.5 5.25 2.5 2.31 4.863 0 8 0s5.5 2.31 5.5 5.25c0 1.516-.701 2.5-1.328 3.259-.095.115-.184.22-.268.319-.207.245-.383.453-.541.681-.208.3-.33.565-.37.847a.751.751 0 0 1-1.485-.212c.084-.593.337-1.078.621-1.489.203-.292.45-.584.673-.848.075-.088.147-.173.213-.253.561-.679.985-1.32.985-2.304 0-2.06-1.637-3.75-4-3.75ZM5.75 12h4.5a.75.75 0 0 1 0 1.5h-4.5a.75.75 0 0 1 0-1.5ZM6 15.25a.75.75 0 0 1 .75-.75h2.5a.75.75 0 0 1 0 1.5h-2.5a.75.75 0 0 1-.75-.75Z"></path></svg>Tip</p>
+            //     <p>Optional information to help a user be more successful.</p>
+            //     </div>
+            //     <div class="markdown-alert markdown-alert-important">
+            //     <p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v9.5A1.75 1.75 0 0 1 14.25 13H8.06l-2.573 2.573A1.458 1.458 0 0 1 3 14.543V13H1.75A1.75 1.75 0 0 1 0 11.25Zm1.75-.25a.25.25 0 0 0-.25.25v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25Zm7 2.25v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 9a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg>Important</p>
+            //     <p>Crucial information necessary for users to succeed.</p>
+            //     </div>
+            //     <div class="markdown-alert markdown-alert-warning">
+            //     <p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg>Warning</p>
+            //     <p>Critical content demanding immediate user attention due to potential risks.</p>
+            //     </div>
+            //     <div class="markdown-alert markdown-alert-caution">
+            //     <p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M4.47.22A.749.749 0 0 1 5 0h6c.199 0 .389.079.53.22l4.25 4.25c.141.14.22.331.22.53v6a.749.749 0 0 1-.22.53l-4.25 4.25A.749.749 0 0 1 11 16H5a.749.749 0 0 1-.53-.22L.22 11.53A.749.749 0 0 1 0 11V5c0-.199.079-.389.22-.53Zm.84 1.28L1.5 5.31v5.38l3.81 3.81h5.38l3.81-3.81V5.31L10.69 1.5ZM8 4a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 4Zm0 8a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Caution</p>
+            //     <p>Negative potential consequences of an action.</p>
+            //     </div>
+
+            TestParser.TestSpec("> [!NOTE]  \n> Highlights information that users should take into account, even when skimming.\n\n> [!TIP]\n> Optional information to help a user be more successful.\n\n> [!IMPORTANT]  \n> Crucial information necessary for users to succeed.\n\n> [!WARNING]  \n> Critical content demanding immediate user attention due to potential risks.\n\n> [!CAUTION]\n> Negative potential consequences of an action.", "<div class=\"markdown-alert markdown-alert-note\">\n<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z\"></path></svg>Note</p>\n<p>Highlights information that users should take into account, even when skimming.</p>\n</div>\n<div class=\"markdown-alert markdown-alert-tip\">\n<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M8 1.5c-2.363 0-4 1.69-4 3.75 0 .984.424 1.625.984 2.304l.214.253c.223.264.47.556.673.848.284.411.537.896.621 1.49a.75.75 0 0 1-1.484.211c-.04-.282-.163-.547-.37-.847a8.456 8.456 0 0 0-.542-.68c-.084-.1-.173-.205-.268-.32C3.201 7.75 2.5 6.766 2.5 5.25 2.5 2.31 4.863 0 8 0s5.5 2.31 5.5 5.25c0 1.516-.701 2.5-1.328 3.259-.095.115-.184.22-.268.319-.207.245-.383.453-.541.681-.208.3-.33.565-.37.847a.751.751 0 0 1-1.485-.212c.084-.593.337-1.078.621-1.489.203-.292.45-.584.673-.848.075-.088.147-.173.213-.253.561-.679.985-1.32.985-2.304 0-2.06-1.637-3.75-4-3.75ZM5.75 12h4.5a.75.75 0 0 1 0 1.5h-4.5a.75.75 0 0 1 0-1.5ZM6 15.25a.75.75 0 0 1 .75-.75h2.5a.75.75 0 0 1 0 1.5h-2.5a.75.75 0 0 1-.75-.75Z\"></path></svg>Tip</p>\n<p>Optional information to help a user be more successful.</p>\n</div>\n<div class=\"markdown-alert markdown-alert-important\">\n<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v9.5A1.75 1.75 0 0 1 14.25 13H8.06l-2.573 2.573A1.458 1.458 0 0 1 3 14.543V13H1.75A1.75 1.75 0 0 1 0 11.25Zm1.75-.25a.25.25 0 0 0-.25.25v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25Zm7 2.25v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 9a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z\"></path></svg>Important</p>\n<p>Crucial information necessary for users to succeed.</p>\n</div>\n<div class=\"markdown-alert markdown-alert-warning\">\n<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z\"></path></svg>Warning</p>\n<p>Critical content demanding immediate user attention due to potential risks.</p>\n</div>\n<div class=\"markdown-alert markdown-alert-caution\">\n<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M4.47.22A.749.749 0 0 1 5 0h6c.199 0 .389.079.53.22l4.25 4.25c.141.14.22.331.22.53v6a.749.749 0 0 1-.22.53l-4.25 4.25A.749.749 0 0 1 11 16H5a.749.749 0 0 1-.53-.22L.22 11.53A.749.749 0 0 1 0 11V5c0-.199.079-.389.22-.53Zm.84 1.28L1.5 5.31v5.38l3.81 3.81h5.38l3.81-3.81V5.31L10.69 1.5ZM8 4a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 4Zm0 8a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z\"></path></svg>Caution</p>\n<p>Negative potential consequences of an action.</p>\n</div>", "advanced", context: "Example 1\nSection Extensions / Alert Blocks\n");
+        }
+
+        // Example with code blocks and mix formatting:
+        [Test]
+        public void ExtensionsAlertBlocks_Example002()
+        {
+            // Example 2
+            // Section: Extensions / Alert Blocks
+            //
+            // The following Markdown:
+            //     > [!NOTE]
+            //     > Highlights information that users should take into account, even when skimming.
+            //     > Testing rendering for multiple lines
+            //     > ```csharp
+            //     > var test = "I can also add code to panels
+            //     > ```
+            //     > `Inline code testing`
+            //
+            // Should be rendered as:
+            //     <div class="markdown-alert markdown-alert-note">
+            //     <p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Note</p>
+            //     <p>Highlights information that users should take into account, even when skimming.
+            //     Testing rendering for multiple lines</p>
+            //     <pre><code class="language-csharp">var test = &quot;I can also add code to panels
+            //     </code></pre>
+            //     <p><code>Inline code testing</code></p>
+            //     </div>
+
+            TestParser.TestSpec("> [!NOTE]\n> Highlights information that users should take into account, even when skimming.\n> Testing rendering for multiple lines\n> ```csharp\n> var test = \"I can also add code to panels\n> ```\n> `Inline code testing`", "<div class=\"markdown-alert markdown-alert-note\">\n<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z\"></path></svg>Note</p>\n<p>Highlights information that users should take into account, even when skimming.\nTesting rendering for multiple lines</p>\n<pre><code class=\"language-csharp\">var test = &quot;I can also add code to panels\n</code></pre>\n<p><code>Inline code testing</code></p>\n</div>", "advanced", context: "Example 2\nSection Extensions / Alert Blocks\n");
+        }
+
+        // Multiline:
+        [Test]
+        public void ExtensionsAlertBlocks_Example003()
+        {
+            // Example 3
+            // Section: Extensions / Alert Blocks
+            //
+            // The following Markdown:
+            //     > [!NOTE]
+            //     > Highlights information that users should take into account, even when skimming.
+            //     > 
+            //     > Testing rendering for multiple lines
+            //     > 
+            //     > `Inline code testing`
+            //     > 
+            //     > Other line
+            //     > 
+            //     > > Nested quote
+            //     > >
+            //     > > Final nested quote line
+            //     > 
+            //     > Final line of alert
+            //
+            // Should be rendered as:
+            //     <div class="markdown-alert markdown-alert-note">
+            //     <p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Note</p>
+            //     <p>Highlights information that users should take into account, even when skimming.</p>
+            //     <p>Testing rendering for multiple lines</p>
+            //     <p><code>Inline code testing</code></p>
+            //     <p>Other line</p>
+            //     <blockquote>
+            //     <p>Nested quote</p>
+            //     <p>Final nested quote line</p>
+            //     </blockquote>
+            //     <p>Final line of alert</p>
+            //     </div>
+
+            TestParser.TestSpec("> [!NOTE]\n> Highlights information that users should take into account, even when skimming.\n> \n> Testing rendering for multiple lines\n> \n> `Inline code testing`\n> \n> Other line\n> \n> > Nested quote\n> >\n> > Final nested quote line\n> \n> Final line of alert", "<div class=\"markdown-alert markdown-alert-note\">\n<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z\"></path></svg>Note</p>\n<p>Highlights information that users should take into account, even when skimming.</p>\n<p>Testing rendering for multiple lines</p>\n<p><code>Inline code testing</code></p>\n<p>Other line</p>\n<blockquote>\n<p>Nested quote</p>\n<p>Final nested quote line</p>\n</blockquote>\n<p>Final line of alert</p>\n</div>", "advanced", context: "Example 3\nSection Extensions / Alert Blocks\n");
+        }
+
+        // An alert inline (e.g `[!NOTE]`) must come first in a quote block, and must be followed by optional spaces with a new line. If no new lines are found, it will not be considered as an alert block.
+        // 
+        // Followed by space and new line:
+        [Test]
+        public void ExtensionsAlertBlocks_Example004()
+        {
+            // Example 4
+            // Section: Extensions / Alert Blocks
+            //
+            // The following Markdown:
+            //     > [!NOTE] This is invalid because no new line
+            //     > Highlights information that users should take into account, even when skimming.
+            //
+            // Should be rendered as:
+            //     <blockquote>
+            //     <p>[!NOTE] This is invalid because no new line
+            //     Highlights information that users should take into account, even when skimming.</p>
+            //     </blockquote>
+
+            TestParser.TestSpec("> [!NOTE] This is invalid because no new line\n> Highlights information that users should take into account, even when skimming.", "<blockquote>\n<p>[!NOTE] This is invalid because no new line\nHighlights information that users should take into account, even when skimming.</p>\n</blockquote>", "advanced", context: "Example 4\nSection Extensions / Alert Blocks\n");
+        }
+
+        // Must come first in a quote block:
+        [Test]
+        public void ExtensionsAlertBlocks_Example005()
+        {
+            // Example 5
+            // Section: Extensions / Alert Blocks
+            //
+            // The following Markdown:
+            //     > This is not a [!NOTE]
+            //     > Highlights information that users should take into account, even when skimming.
+            //
+            // Should be rendered as:
+            //     <blockquote>
+            //     <p>This is not a [!NOTE]
+            //     Highlights information that users should take into account, even when skimming.</p>
+            //     </blockquote>
+
+            TestParser.TestSpec("> This is not a [!NOTE]\n> Highlights information that users should take into account, even when skimming.", "<blockquote>\n<p>This is not a [!NOTE]\nHighlights information that users should take into account, even when skimming.</p>\n</blockquote>", "advanced", context: "Example 5\nSection Extensions / Alert Blocks\n");
+        }
+    }
+}

src/Markdig.Tests/Specs/AlertBlockSpecs.md

@@ -0,0 +1,127 @@
+# Extensions
+
+This section describes the different extensions supported:
+
+## Alert Blocks
+
+This is supporting the [GitHub Alert blocks](https://github.com/orgs/community/discussions/16925)
+
+```````````````````````````````` example
+> [!NOTE]  
+> Highlights information that users should take into account, even when skimming.
+
+> [!TIP]
+> Optional information to help a user be more successful.
+
+> [!IMPORTANT]  
+> Crucial information necessary for users to succeed.
+
+> [!WARNING]  
+> Critical content demanding immediate user attention due to potential risks.
+
+> [!CAUTION]
+> Negative potential consequences of an action.
+.
+<div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Note</p>
+<p>Highlights information that users should take into account, even when skimming.</p>
+</div>
+<div class="markdown-alert markdown-alert-tip">
+<p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M8 1.5c-2.363 0-4 1.69-4 3.75 0 .984.424 1.625.984 2.304l.214.253c.223.264.47.556.673.848.284.411.537.896.621 1.49a.75.75 0 0 1-1.484.211c-.04-.282-.163-.547-.37-.847a8.456 8.456 0 0 0-.542-.68c-.084-.1-.173-.205-.268-.32C3.201 7.75 2.5 6.766 2.5 5.25 2.5 2.31 4.863 0 8 0s5.5 2.31 5.5 5.25c0 1.516-.701 2.5-1.328 3.259-.095.115-.184.22-.268.319-.207.245-.383.453-.541.681-.208.3-.33.565-.37.847a.751.751 0 0 1-1.485-.212c.084-.593.337-1.078.621-1.489.203-.292.45-.584.673-.848.075-.088.147-.173.213-.253.561-.679.985-1.32.985-2.304 0-2.06-1.637-3.75-4-3.75ZM5.75 12h4.5a.75.75 0 0 1 0 1.5h-4.5a.75.75 0 0 1 0-1.5ZM6 15.25a.75.75 0 0 1 .75-.75h2.5a.75.75 0 0 1 0 1.5h-2.5a.75.75 0 0 1-.75-.75Z"></path></svg>Tip</p>
+<p>Optional information to help a user be more successful.</p>
+</div>
+<div class="markdown-alert markdown-alert-important">
+<p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v9.5A1.75 1.75 0 0 1 14.25 13H8.06l-2.573 2.573A1.458 1.458 0 0 1 3 14.543V13H1.75A1.75 1.75 0 0 1 0 11.25Zm1.75-.25a.25.25 0 0 0-.25.25v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25Zm7 2.25v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 9a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg>Important</p>
+<p>Crucial information necessary for users to succeed.</p>
+</div>
+<div class="markdown-alert markdown-alert-warning">
+<p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg>Warning</p>
+<p>Critical content demanding immediate user attention due to potential risks.</p>
+</div>
+<div class="markdown-alert markdown-alert-caution">
+<p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M4.47.22A.749.749 0 0 1 5 0h6c.199 0 .389.079.53.22l4.25 4.25c.141.14.22.331.22.53v6a.749.749 0 0 1-.22.53l-4.25 4.25A.749.749 0 0 1 11 16H5a.749.749 0 0 1-.53-.22L.22 11.53A.749.749 0 0 1 0 11V5c0-.199.079-.389.22-.53Zm.84 1.28L1.5 5.31v5.38l3.81 3.81h5.38l3.81-3.81V5.31L10.69 1.5ZM8 4a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 4Zm0 8a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Caution</p>
+<p>Negative potential consequences of an action.</p>
+</div>
+````````````````````````````````
+
+Example with code blocks and mix formatting:
+
+
+```````````````````````````````` example
+> [!NOTE]
+> Highlights information that users should take into account, even when skimming.
+> Testing rendering for multiple lines
+> ```csharp
+> var test = "I can also add code to panels
+> ```
+> `Inline code testing`
+.
+<div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Note</p>
+<p>Highlights information that users should take into account, even when skimming.
+Testing rendering for multiple lines</p>
+<pre><code class="language-csharp">var test = &quot;I can also add code to panels
+</code></pre>
+<p><code>Inline code testing</code></p>
+</div>
+````````````````````````````````
+
+Multiline:
+
+```````````````````````````````` example
+> [!NOTE]
+> Highlights information that users should take into account, even when skimming.
+> 
+> Testing rendering for multiple lines
+> 
+> `Inline code testing`
+> 
+> Other line
+> 
+> > Nested quote
+> >
+> > Final nested quote line
+> 
+> Final line of alert
+.
+<div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title"><svg viewBox="0 0 16 16" version="1.1" width="16" height="16" aria-hidden="true"><path d="M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z"></path></svg>Note</p>
+<p>Highlights information that users should take into account, even when skimming.</p>
+<p>Testing rendering for multiple lines</p>
+<p><code>Inline code testing</code></p>
+<p>Other line</p>
+<blockquote>
+<p>Nested quote</p>
+<p>Final nested quote line</p>
+</blockquote>
+<p>Final line of alert</p>
+</div>
+````````````````````````````````
+
+An alert inline (e.g `[!NOTE]`) must come first in a quote block, and must be followed by optional spaces with a new line. If no new lines are found, it will not be considered as an alert block.
+
+Followed by space and new line:
+
+```````````````````````````````` example
+> [!NOTE] This is invalid because no new line
+> Highlights information that users should take into account, even when skimming.
+.
+<blockquote>
+<p>[!NOTE] This is invalid because no new line
+Highlights information that users should take into account, even when skimming.</p>
+</blockquote>
+````````````````````````````````
+
+Must come first in a quote block:
+
+```````````````````````````````` example
+> This is not a [!NOTE]
+> Highlights information that users should take into account, even when skimming.
+.
+<blockquote>
+<p>This is not a [!NOTE]
+Highlights information that users should take into account, even when skimming.</p>
+</blockquote>
+````````````````````````````````
+
+

src/Markdig.Tests/Specs/AutoIdentifierSpecs.generated.cs

@@ -0,0 +1,212 @@
+
+// --------------------------------
+//         Auto Identifiers
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.AutoIdentifiers
+{
+    [TestFixture]
+    public class TestExtensionsHeadingAutoIdentifiers
+    {
+        // # Extensions
+        // 
+        // This section describes the auto identifier extension
+        // 
+        // ## Heading Auto Identifiers
+        // 
+        // Allows to automatically creates an identifier for a heading:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example001()
+        {
+            // Example 1
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     # This is a heading
+            //
+            // Should be rendered as:
+            //     <h1 id="this-is-a-heading">This is a heading</h1>
+
+            TestParser.TestSpec("# This is a heading", "<h1 id=\"this-is-a-heading\">This is a heading</h1>", "autoidentifiers|advanced", context: "Example 1\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // Only punctuation `-`, `_` and `.` is kept, all other non letter characters are discarded.
+        // Consecutive same character `-`, `_` or `.` are rendered into a single one
+        // Characters `-`, `_` and `.` at the end of the string are also discarded.
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example002()
+        {
+            // Example 2
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     # This - is a &@! heading _ with . and ! -
+            //
+            // Should be rendered as:
+            //     <h1 id="this-is-a-heading_with.and">This - is a &amp;@! heading _ with . and ! -</h1>
+
+            TestParser.TestSpec("# This - is a &@! heading _ with . and ! -", "<h1 id=\"this-is-a-heading_with.and\">This - is a &amp;@! heading _ with . and ! -</h1>", "autoidentifiers|advanced", context: "Example 2\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // Formatting (emphasis) are also discarded:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example003()
+        {
+            // Example 3
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     # This is a *heading*
+            //
+            // Should be rendered as:
+            //     <h1 id="this-is-a-heading">This is a <em>heading</em></h1>
+
+            TestParser.TestSpec("# This is a *heading*", "<h1 id=\"this-is-a-heading\">This is a <em>heading</em></h1>", "autoidentifiers|advanced", context: "Example 3\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // Links are also removed:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example004()
+        {
+            // Example 4
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     # This is a [heading](/url)
+            //
+            // Should be rendered as:
+            //     <h1 id="this-is-a-heading">This is a <a href="/url">heading</a></h1>
+
+            TestParser.TestSpec("# This is a [heading](/url)", "<h1 id=\"this-is-a-heading\">This is a <a href=\"/url\">heading</a></h1>", "autoidentifiers|advanced", context: "Example 4\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // If multiple heading have the same text, -1, -2...-n will be postfix to the header id.
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example005()
+        {
+            // Example 5
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     # This is a heading
+            //     # This is a heading
+            //
+            // Should be rendered as:
+            //     <h1 id="this-is-a-heading">This is a heading</h1>
+            //     <h1 id="this-is-a-heading-1">This is a heading</h1>
+
+            TestParser.TestSpec("# This is a heading\n# This is a heading", "<h1 id=\"this-is-a-heading\">This is a heading</h1>\n<h1 id=\"this-is-a-heading-1\">This is a heading</h1>", "autoidentifiers|advanced", context: "Example 5\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // The heading Id will start on the first letter character of the heading, all previous characters will be discarded:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example006()
+        {
+            // Example 6
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     # 1.0 This is a heading
+            //
+            // Should be rendered as:
+            //     <h1 id="this-is-a-heading">1.0 This is a heading</h1>
+
+            TestParser.TestSpec("# 1.0 This is a heading", "<h1 id=\"this-is-a-heading\">1.0 This is a heading</h1>", "autoidentifiers|advanced", context: "Example 6\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // If the heading is all stripped by the previous rules, the id `section` will be used instead:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example007()
+        {
+            // Example 7
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     # 1.0 & ^ % *
+            //     # 1.0 & ^ % *
+            //
+            // Should be rendered as:
+            //     <h1 id="section">1.0 &amp; ^ % *</h1>
+            //     <h1 id="section-1">1.0 &amp; ^ % *</h1>
+
+            TestParser.TestSpec("# 1.0 & ^ % *\n# 1.0 & ^ % *", "<h1 id=\"section\">1.0 &amp; ^ % *</h1>\n<h1 id=\"section-1\">1.0 &amp; ^ % *</h1>", "autoidentifiers|advanced", context: "Example 7\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // When the options "AutoLink" is setup, it is possible to link to an existing heading by using the 
+        // exact same Label text as the heading:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example008()
+        {
+            // Example 8
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     # This is a heading
+            //     [This is a heading]
+            //
+            // Should be rendered as:
+            //     <h1 id="this-is-a-heading">This is a heading</h1>
+            //     <p><a href="#this-is-a-heading">This is a heading</a></p>
+
+            TestParser.TestSpec("# This is a heading\n[This is a heading]", "<h1 id=\"this-is-a-heading\">This is a heading</h1>\n<p><a href=\"#this-is-a-heading\">This is a heading</a></p>", "autoidentifiers|advanced", context: "Example 8\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // Links before the heading are also working:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example009()
+        {
+            // Example 9
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     [This is a heading]
+            //     # This is a heading
+            //
+            // Should be rendered as:
+            //     <p><a href="#this-is-a-heading">This is a heading</a></p>
+            //     <h1 id="this-is-a-heading">This is a heading</h1>
+
+            TestParser.TestSpec("[This is a heading]\n# This is a heading", "<p><a href=\"#this-is-a-heading\">This is a heading</a></p>\n<h1 id=\"this-is-a-heading\">This is a heading</h1>", "autoidentifiers|advanced", context: "Example 9\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // The text of the link can be changed:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example010()
+        {
+            // Example 10
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     [With a new text][This is a heading]
+            //     # This is a heading
+            //
+            // Should be rendered as:
+            //     <p><a href="#this-is-a-heading">With a new text</a></p>
+            //     <h1 id="this-is-a-heading">This is a heading</h1>
+
+            TestParser.TestSpec("[With a new text][This is a heading]\n# This is a heading", "<p><a href=\"#this-is-a-heading\">With a new text</a></p>\n<h1 id=\"this-is-a-heading\">This is a heading</h1>", "autoidentifiers|advanced", context: "Example 10\nSection Extensions / Heading Auto Identifiers\n");
+        }
+
+        // An autoidentifier should not conflict with an existing link:
+        [Test]
+        public void ExtensionsHeadingAutoIdentifiers_Example011()
+        {
+            // Example 11
+            // Section: Extensions / Heading Auto Identifiers
+            //
+            // The following Markdown:
+            //     ![scenario image][scenario]
+            //     ## Scenario
+            //     [scenario]: ./scenario.png
+            //
+            // Should be rendered as:
+            //     <p><img src="./scenario.png" alt="scenario image" /></p>
+            //     <h2 id="scenario">Scenario</h2>
+
+            TestParser.TestSpec("![scenario image][scenario]\n## Scenario\n[scenario]: ./scenario.png", "<p><img src=\"./scenario.png\" alt=\"scenario image\" /></p>\n<h2 id=\"scenario\">Scenario</h2>", "autoidentifiers|advanced", context: "Example 11\nSection Extensions / Heading Auto Identifiers\n");
+        }
+    }
+}

src/Markdig.Tests/Specs/AutoIdentifierSpecs.md

@@ -12,7 +12,7 @@ Allows to automatically creates an identifier for a heading:
 <h1 id="this-is-a-heading">This is a heading</h1>
 ````````````````````````````````
 
-Only punctuation `-`, `_` and `.` is kept, all over non letter characters are discarded.
+Only punctuation `-`, `_` and `.` is kept, all other non letter characters are discarded.
 Consecutive same character `-`, `_` or `.` are rendered into a single one
 Characters `-`, `_` and `.` at the end of the string are also discarded.
 
@@ -96,3 +96,14 @@ The text of the link can be changed:
 <p><a href="#this-is-a-heading">With a new text</a></p>
 <h1 id="this-is-a-heading">This is a heading</h1>
 ````````````````````````````````
+
+An autoidentifier should not conflict with an existing link:
+
+```````````````````````````````` example
+![scenario image][scenario]
+## Scenario
+[scenario]: ./scenario.png
+.
+<p><img src="./scenario.png" alt="scenario image" /></p>
+<h2 id="scenario">Scenario</h2>
+````````````````````````````````

src/Markdig.Tests/Specs/AutoLinks.generated.cs

@@ -0,0 +1,560 @@
+
+// --------------------------------
+//            Auto Links
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.AutoLinks
+{
+    [TestFixture]
+    public class TestExtensionsAutoLinks
+    {
+        // # Extensions
+        // 
+        // This section describes the different extensions supported:
+        // 
+        // ## AutoLinks
+        // 
+        // Autolinks will format as a HTML link any string that starts by:
+        // 
+        // - `http://` or `https://` 
+        // - `ftp://`
+        // - `mailto:`
+        // - `tel:`
+        // - `www.` 
+        [Test]
+        public void ExtensionsAutoLinks_Example001()
+        {
+            // Example 1
+            // Section: Extensions / AutoLinks
+            //
+            // The following Markdown:
+            //     This is a http://www.google.com URL and https://www.google.com
+            //     This is a ftp://test.com
+            //     And a mailto:email@toto.com
+            //     And a tel:+1555123456
+            //     And a plain www.google.com
+            //
+            // Should be rendered as:
+            //     <p>This is a <a href="http://www.google.com">http://www.google.com</a> URL and <a href="https://www.google.com">https://www.google.com</a>
+            //     This is a <a href="ftp://test.com">ftp://test.com</a>
+            //     And a <a href="mailto:email@toto.com">email@toto.com</a>
+            //     And a <a href="tel:+1555123456">+1555123456</a>
+            //     And a plain <a href="http://www.google.com">www.google.com</a></p>
+
+            TestParser.TestSpec("This is a http://www.google.com URL and https://www.google.com\nThis is a ftp://test.com\nAnd a mailto:email@toto.com\nAnd a tel:+1555123456\nAnd a plain www.google.com", "<p>This is a <a href=\"http://www.google.com\">http://www.google.com</a> URL and <a href=\"https://www.google.com\">https://www.google.com</a>\nThis is a <a href=\"ftp://test.com\">ftp://test.com</a>\nAnd a <a href=\"mailto:email@toto.com\">email@toto.com</a>\nAnd a <a href=\"tel:+1555123456\">+1555123456</a>\nAnd a plain <a href=\"http://www.google.com\">www.google.com</a></p>", "autolinks|advanced", context: "Example 1\nSection Extensions / AutoLinks\n");
+        }
+
+        // But incomplete links will not be matched:
+        [Test]
+        public void ExtensionsAutoLinks_Example002()
+        {
+            // Example 2
+            // Section: Extensions / AutoLinks
+            //
+            // The following Markdown:
+            //     This is not a http:/www.google.com URL and https:/www.google.com
+            //     This is not a ftp:/test.com
+            //     And not a mailto:emailtoto.com
+            //     And not a plain www. or a www.x 
+            //     And not a tel:
+            //
+            // Should be rendered as:
+            //     <p>This is not a http:/www.google.com URL and https:/www.google.com
+            //     This is not a ftp:/test.com
+            //     And not a mailto:emailtoto.com
+            //     And not a plain www. or a www.x
+            //     And not a tel:</p>
+
+            TestParser.TestSpec("This is not a http:/www.google.com URL and https:/www.google.com\nThis is not a ftp:/test.com\nAnd not a mailto:emailtoto.com\nAnd not a plain www. or a www.x \nAnd not a tel:", "<p>This is not a http:/www.google.com URL and https:/www.google.com\nThis is not a ftp:/test.com\nAnd not a mailto:emailtoto.com\nAnd not a plain www. or a www.x\nAnd not a tel:</p>", "autolinks|advanced", context: "Example 2\nSection Extensions / AutoLinks\n");
+        }
+
+        // Previous character must be a punctuation or a valid space (tab, space, new line):
+        [Test]
+        public void ExtensionsAutoLinks_Example003()
+        {
+            // Example 3
+            // Section: Extensions / AutoLinks
+            //
+            // The following Markdown:
+            //     This is not a nhttp://www.google.com URL but this is (https://www.google.com)
+            //
+            // Should be rendered as:
+            //     <p>This is not a nhttp://www.google.com URL but this is (<a href="https://www.google.com">https://www.google.com</a>)</p>
+
+            TestParser.TestSpec("This is not a nhttp://www.google.com URL but this is (https://www.google.com)", "<p>This is not a nhttp://www.google.com URL but this is (<a href=\"https://www.google.com\">https://www.google.com</a>)</p>", "autolinks|advanced", context: "Example 3\nSection Extensions / AutoLinks\n");
+        }
+
+        // An autolink should not interfere with an `<a>` HTML inline:
+        [Test]
+        public void ExtensionsAutoLinks_Example004()
+        {
+            // Example 4
+            // Section: Extensions / AutoLinks
+            //
+            // The following Markdown:
+            //     This is an HTML <a href="http://www.google.com">http://www.google.com</a> link
+            //
+            // Should be rendered as:
+            //     <p>This is an HTML <a href="http://www.google.com">http://www.google.com</a> link</p>
+
+            TestParser.TestSpec("This is an HTML <a href=\"http://www.google.com\">http://www.google.com</a> link", "<p>This is an HTML <a href=\"http://www.google.com\">http://www.google.com</a> link</p>", "autolinks|advanced", context: "Example 4\nSection Extensions / AutoLinks\n");
+        }
+
+        // or even within emphasis:
+        [Test]
+        public void ExtensionsAutoLinks_Example005()
+        {
+            // Example 5
+            // Section: Extensions / AutoLinks
+            //
+            // The following Markdown:
+            //     This is an HTML <a href="http://www.google.com"> **http://www.google.com** </a> link
+            //
+            // Should be rendered as:
+            //     <p>This is an HTML <a href="http://www.google.com"> <strong>http://www.google.com</strong> </a> link</p>
+
+            TestParser.TestSpec("This is an HTML <a href=\"http://www.google.com\"> **http://www.google.com** </a> link", "<p>This is an HTML <a href=\"http://www.google.com\"> <strong>http://www.google.com</strong> </a> link</p>", "autolinks|advanced", context: "Example 5\nSection Extensions / AutoLinks\n");
+        }
+
+        // An autolink should not interfere with a markdown link:
+        [Test]
+        public void ExtensionsAutoLinks_Example006()
+        {
+            // Example 6
+            // Section: Extensions / AutoLinks
+            //
+            // The following Markdown:
+            //     This is an HTML [http://www.google.com](http://www.google.com) link
+            //
+            // Should be rendered as:
+            //     <p>This is an HTML <a href="http://www.google.com">http://www.google.com</a> link</p>
+
+            TestParser.TestSpec("This is an HTML [http://www.google.com](http://www.google.com) link", "<p>This is an HTML <a href=\"http://www.google.com\">http://www.google.com</a> link</p>", "autolinks|advanced", context: "Example 6\nSection Extensions / AutoLinks\n");
+        }
+
+        // A link embraced by pending emphasis should let the emphasis takes precedence if characters are placed at the end of the matched link:
+        [Test]
+        public void ExtensionsAutoLinks_Example007()
+        {
+            // Example 7
+            // Section: Extensions / AutoLinks
+            //
+            // The following Markdown:
+            //     Check **http://www.a.com** or __http://www.b.com__
+            //
+            // Should be rendered as:
+            //     <p>Check <strong><a href="http://www.a.com">http://www.a.com</a></strong> or <strong><a href="http://www.b.com">http://www.b.com</a></strong></p>
+
+            TestParser.TestSpec("Check **http://www.a.com** or __http://www.b.com__", "<p>Check <strong><a href=\"http://www.a.com\">http://www.a.com</a></strong> or <strong><a href=\"http://www.b.com\">http://www.b.com</a></strong></p>", "autolinks|advanced", context: "Example 7\nSection Extensions / AutoLinks\n");
+        }
+
+        // It is not mentioned by the spec, but empty emails won't be matched (only a subset of [RFC2368](https://tools.ietf.org/html/rfc2368) is supported by auto links):
+        [Test]
+        public void ExtensionsAutoLinks_Example008()
+        {
+            // Example 8
+            // Section: Extensions / AutoLinks
+            //
+            // The following Markdown:
+            //     mailto:email@test.com is okay, but mailto:@test.com is not
+            //
+            // Should be rendered as:
+            //     <p><a href="mailto:email@test.com">email@test.com</a> is okay, but mailto:@test.com is not</p>
+
+            TestParser.TestSpec("mailto:email@test.com is okay, but mailto:@test.com is not", "<p><a href=\"mailto:email@test.com\">email@test.com</a> is okay, but mailto:@test.com is not</p>", "autolinks|advanced", context: "Example 8\nSection Extensions / AutoLinks\n");
+        }
+    }
+
+    [TestFixture]
+    public class TestExtensionsAutoLinksGFMSupport
+    {
+        // ### GFM Support
+        // 
+        // Extract from [GFM Autolinks extensions specs](https://github.github.com/gfm/#autolinks-extension-)
+        [Test]
+        public void ExtensionsAutoLinksGFMSupport_Example009()
+        {
+            // Example 9
+            // Section: Extensions / AutoLinks / GFM Support
+            //
+            // The following Markdown:
+            //     www.commonmark.org
+            //
+            // Should be rendered as:
+            //     <p><a href="http://www.commonmark.org">www.commonmark.org</a></p>
+
+            TestParser.TestSpec("www.commonmark.org", "<p><a href=\"http://www.commonmark.org\">www.commonmark.org</a></p>", "autolinks|advanced", context: "Example 9\nSection Extensions / AutoLinks / GFM Support\n");
+        }
+
+        [Test]
+        public void ExtensionsAutoLinksGFMSupport_Example010()
+        {
+            // Example 10
+            // Section: Extensions / AutoLinks / GFM Support
+            //
+            // The following Markdown:
+            //     Visit www.commonmark.org/help for more information.
+            //
+            // Should be rendered as:
+            //     <p>Visit <a href="http://www.commonmark.org/help">www.commonmark.org/help</a> for more information.</p>
+
+            TestParser.TestSpec("Visit www.commonmark.org/help for more information.", "<p>Visit <a href=\"http://www.commonmark.org/help\">www.commonmark.org/help</a> for more information.</p>", "autolinks|advanced", context: "Example 10\nSection Extensions / AutoLinks / GFM Support\n");
+        }
+
+        [Test]
+        public void ExtensionsAutoLinksGFMSupport_Example011()
+        {
+            // Example 11
+            // Section: Extensions / AutoLinks / GFM Support
+            //
+            // The following Markdown:
+            //     Visit www.commonmark.org.
+            //     
+            //     Visit www.commonmark.org/a.b.
+            //
+            // Should be rendered as:
+            //     <p>Visit <a href="http://www.commonmark.org">www.commonmark.org</a>.</p>
+            //     <p>Visit <a href="http://www.commonmark.org/a.b">www.commonmark.org/a.b</a>.</p>
+
+            TestParser.TestSpec("Visit www.commonmark.org.\n\nVisit www.commonmark.org/a.b.", "<p>Visit <a href=\"http://www.commonmark.org\">www.commonmark.org</a>.</p>\n<p>Visit <a href=\"http://www.commonmark.org/a.b\">www.commonmark.org/a.b</a>.</p>", "autolinks|advanced", context: "Example 11\nSection Extensions / AutoLinks / GFM Support\n");
+        }
+
+        [Test]
+        public void ExtensionsAutoLinksGFMSupport_Example012()
+        {
+            // Example 12
+            // Section: Extensions / AutoLinks / GFM Support
+            //
+            // The following Markdown:
+            //     www.google.com/search?q=Markup+(business)
+            //     
+            //     (www.google.com/search?q=Markup+(business))
+            //
+            // Should be rendered as:
+            //     <p><a href="http://www.google.com/search?q=Markup+(business)">www.google.com/search?q=Markup+(business)</a></p>
+            //     <p>(<a href="http://www.google.com/search?q=Markup+(business)">www.google.com/search?q=Markup+(business)</a>)</p>
+
+            TestParser.TestSpec("www.google.com/search?q=Markup+(business)\n\n(www.google.com/search?q=Markup+(business))", "<p><a href=\"http://www.google.com/search?q=Markup+(business)\">www.google.com/search?q=Markup+(business)</a></p>\n<p>(<a href=\"http://www.google.com/search?q=Markup+(business)\">www.google.com/search?q=Markup+(business)</a>)</p>", "autolinks|advanced", context: "Example 12\nSection Extensions / AutoLinks / GFM Support\n");
+        }
+
+        [Test]
+        public void ExtensionsAutoLinksGFMSupport_Example013()
+        {
+            // Example 13
+            // Section: Extensions / AutoLinks / GFM Support
+            //
+            // The following Markdown:
+            //     www.google.com/search?q=commonmark&hl=en
+            //     
+            //     www.google.com/search?q=commonmark&hl;
+            //
+            // Should be rendered as:
+            //     <p><a href="http://www.google.com/search?q=commonmark&amp;hl=en">www.google.com/search?q=commonmark&amp;hl=en</a></p>
+            //     <p><a href="http://www.google.com/search?q=commonmark">www.google.com/search?q=commonmark</a>&amp;hl;</p>
+
+            TestParser.TestSpec("www.google.com/search?q=commonmark&hl=en\n\nwww.google.com/search?q=commonmark&hl;", "<p><a href=\"http://www.google.com/search?q=commonmark&amp;hl=en\">www.google.com/search?q=commonmark&amp;hl=en</a></p>\n<p><a href=\"http://www.google.com/search?q=commonmark\">www.google.com/search?q=commonmark</a>&amp;hl;</p>", "autolinks|advanced", context: "Example 13\nSection Extensions / AutoLinks / GFM Support\n");
+        }
+
+        [Test]
+        public void ExtensionsAutoLinksGFMSupport_Example014()
+        {
+            // Example 14
+            // Section: Extensions / AutoLinks / GFM Support
+            //
+            // The following Markdown:
+            //     www.commonmark.org/he<lp
+            //
+            // Should be rendered as:
+            //     <p><a href="http://www.commonmark.org/he">www.commonmark.org/he</a>&lt;lp</p>
+
+            TestParser.TestSpec("www.commonmark.org/he<lp", "<p><a href=\"http://www.commonmark.org/he\">www.commonmark.org/he</a>&lt;lp</p>", "autolinks|advanced", context: "Example 14\nSection Extensions / AutoLinks / GFM Support\n");
+        }
+
+        [Test]
+        public void ExtensionsAutoLinksGFMSupport_Example015()
+        {
+            // Example 15
+            // Section: Extensions / AutoLinks / GFM Support
+            //
+            // The following Markdown:
+            //     http://commonmark.org
+            //     
+            //     (Visit https://encrypted.google.com/search?q=Markup+(business))
+            //     
+            //     Anonymous FTP is available at ftp://foo.bar.baz.
+            //
+            // Should be rendered as:
+            //     <p><a href="http://commonmark.org">http://commonmark.org</a></p>
+            //     <p>(Visit <a href="https://encrypted.google.com/search?q=Markup+(business)">https://encrypted.google.com/search?q=Markup+(business)</a>)</p>
+            //     <p>Anonymous FTP is available at <a href="ftp://foo.bar.baz">ftp://foo.bar.baz</a>.</p>
+
+            TestParser.TestSpec("http://commonmark.org\n\n(Visit https://encrypted.google.com/search?q=Markup+(business))\n\nAnonymous FTP is available at ftp://foo.bar.baz.", "<p><a href=\"http://commonmark.org\">http://commonmark.org</a></p>\n<p>(Visit <a href=\"https://encrypted.google.com/search?q=Markup+(business)\">https://encrypted.google.com/search?q=Markup+(business)</a>)</p>\n<p>Anonymous FTP is available at <a href=\"ftp://foo.bar.baz\">ftp://foo.bar.baz</a>.</p>", "autolinks|advanced", context: "Example 15\nSection Extensions / AutoLinks / GFM Support\n");
+        }
+    }
+
+    [TestFixture]
+    public class TestExtensionsAutoLinksValidDomainTests
+    {
+        // ### Valid Domain Tests
+        // 
+        // Domain names that have empty segments won't be matched
+        [Test]
+        public void ExtensionsAutoLinksValidDomainTests_Example016()
+        {
+            // Example 16
+            // Section: Extensions / AutoLinks / Valid Domain Tests
+            //
+            // The following Markdown:
+            //     www..
+            //     www..com
+            //     http://test.
+            //     http://.test
+            //     http://.
+            //     http://..
+            //     ftp://test.
+            //     ftp://.test
+            //     mailto:email@test.
+            //     mailto:email@.test
+            //
+            // Should be rendered as:
+            //     <p>www..
+            //     www..com
+            //     http://test.
+            //     http://.test
+            //     http://.
+            //     http://..
+            //     ftp://test.
+            //     ftp://.test
+            //     mailto:email@test.
+            //     mailto:email@.test</p>
+
+            TestParser.TestSpec("www..\nwww..com\nhttp://test.\nhttp://.test\nhttp://.\nhttp://..\nftp://test.\nftp://.test\nmailto:email@test.\nmailto:email@.test", "<p>www..\nwww..com\nhttp://test.\nhttp://.test\nhttp://.\nhttp://..\nftp://test.\nftp://.test\nmailto:email@test.\nmailto:email@.test</p>", "autolinks|advanced", context: "Example 16\nSection Extensions / AutoLinks / Valid Domain Tests\n");
+        }
+
+        // Domain names with too few segments won't be matched
+        [Test]
+        public void ExtensionsAutoLinksValidDomainTests_Example017()
+        {
+            // Example 17
+            // Section: Extensions / AutoLinks / Valid Domain Tests
+            //
+            // The following Markdown:
+            //     www
+            //     www.com
+            //     http://test
+            //     ftp://test
+            //     mailto:email@test
+            //
+            // Should be rendered as:
+            //     <p>www
+            //     www.com
+            //     http://test
+            //     ftp://test
+            //     mailto:email@test</p>
+
+            TestParser.TestSpec("www\nwww.com\nhttp://test\nftp://test\nmailto:email@test", "<p>www\nwww.com\nhttp://test\nftp://test\nmailto:email@test</p>", "autolinks|advanced", context: "Example 17\nSection Extensions / AutoLinks / Valid Domain Tests\n");
+        }
+
+        // Domain names that contain an underscores in the last two segments won't be matched
+        [Test]
+        public void ExtensionsAutoLinksValidDomainTests_Example018()
+        {
+            // Example 18
+            // Section: Extensions / AutoLinks / Valid Domain Tests
+            //
+            // The following Markdown:
+            //     www._test.foo.bar is okay, but www._test.foo is not
+            //     
+            //     http://te_st.foo.bar is okay, as is http://test.foo_.bar.foo
+            //     
+            //     But http://te_st.foo, http://test.foo_.bar and http://test._foo are not
+            //     
+            //     ftp://test_.foo.bar is okay, but ftp://test.fo_o is not
+            //     
+            //     mailto:email@_test.foo.bar is okay, but mailto:email@_test.foo is not
+            //
+            // Should be rendered as:
+            //     <p><a href="http://www._test.foo.bar">www._test.foo.bar</a> is okay, but www._test.foo is not</p>
+            //     <p><a href="http://te_st.foo.bar">http://te_st.foo.bar</a> is okay, as is <a href="http://test.foo_.bar.foo">http://test.foo_.bar.foo</a></p>
+            //     <p>But http://te_st.foo, http://test.foo_.bar and http://test._foo are not</p>
+            //     <p><a href="ftp://test_.foo.bar">ftp://test_.foo.bar</a> is okay, but ftp://test.fo_o is not</p>
+            //     <p><a href="mailto:email@_test.foo.bar">email@_test.foo.bar</a> is okay, but mailto:email@_test.foo is not</p>
+
+            TestParser.TestSpec("www._test.foo.bar is okay, but www._test.foo is not\n\nhttp://te_st.foo.bar is okay, as is http://test.foo_.bar.foo\n\nBut http://te_st.foo, http://test.foo_.bar and http://test._foo are not\n\nftp://test_.foo.bar is okay, but ftp://test.fo_o is not\n\nmailto:email@_test.foo.bar is okay, but mailto:email@_test.foo is not", "<p><a href=\"http://www._test.foo.bar\">www._test.foo.bar</a> is okay, but www._test.foo is not</p>\n<p><a href=\"http://te_st.foo.bar\">http://te_st.foo.bar</a> is okay, as is <a href=\"http://test.foo_.bar.foo\">http://test.foo_.bar.foo</a></p>\n<p>But http://te_st.foo, http://test.foo_.bar and http://test._foo are not</p>\n<p><a href=\"ftp://test_.foo.bar\">ftp://test_.foo.bar</a> is okay, but ftp://test.fo_o is not</p>\n<p><a href=\"mailto:email@_test.foo.bar\">email@_test.foo.bar</a> is okay, but mailto:email@_test.foo is not</p>", "autolinks|advanced", context: "Example 18\nSection Extensions / AutoLinks / Valid Domain Tests\n");
+        }
+
+        // Domain names that contain invalid characters (not AlphaNumberic, -, _ or .) won't be matched
+        [Test]
+        public void ExtensionsAutoLinksValidDomainTests_Example019()
+        {
+            // Example 19
+            // Section: Extensions / AutoLinks / Valid Domain Tests
+            //
+            // The following Markdown:
+            //     https://[your-domain]/api
+            //
+            // Should be rendered as:
+            //     <p>https://[your-domain]/api</p>
+
+            TestParser.TestSpec("https://[your-domain]/api", "<p>https://[your-domain]/api</p>", "autolinks|advanced", context: "Example 19\nSection Extensions / AutoLinks / Valid Domain Tests\n");
+        }
+
+        // Domain names followed by ?, : or # instead of / are matched
+        [Test]
+        public void ExtensionsAutoLinksValidDomainTests_Example020()
+        {
+            // Example 20
+            // Section: Extensions / AutoLinks / Valid Domain Tests
+            //
+            // The following Markdown:
+            //     https://github.com?
+            //     
+            //     https://github.com?a
+            //     
+            //     https://github.com#a
+            //     
+            //     https://github.com:
+            //     
+            //     https://github.com:443
+            //
+            // Should be rendered as:
+            //     <p><a href="https://github.com">https://github.com</a>?</p>
+            //     <p><a href="https://github.com?a">https://github.com?a</a></p>
+            //     <p><a href="https://github.com#a">https://github.com#a</a></p>
+            //     <p><a href="https://github.com">https://github.com</a>:</p>
+            //     <p><a href="https://github.com:443">https://github.com:443</a></p>
+
+            TestParser.TestSpec("https://github.com?\n\nhttps://github.com?a\n\nhttps://github.com#a\n\nhttps://github.com:\n\nhttps://github.com:443", "<p><a href=\"https://github.com\">https://github.com</a>?</p>\n<p><a href=\"https://github.com?a\">https://github.com?a</a></p>\n<p><a href=\"https://github.com#a\">https://github.com#a</a></p>\n<p><a href=\"https://github.com\">https://github.com</a>:</p>\n<p><a href=\"https://github.com:443\">https://github.com:443</a></p>", "autolinks|advanced", context: "Example 20\nSection Extensions / AutoLinks / Valid Domain Tests\n");
+        }
+    }
+
+    [TestFixture]
+    public class TestExtensionsAutoLinksUnicodeSupport
+    {
+        // ### Unicode support
+        // 
+        // Links with unicode characters in the path / query / fragment are matched and url encoded
+        [Test]
+        public void ExtensionsAutoLinksUnicodeSupport_Example021()
+        {
+            // Example 21
+            // Section: Extensions / AutoLinks / Unicode support
+            //
+            // The following Markdown:
+            //     http://abc.net/☃
+            //     
+            //     http://abc.net?☃
+            //     
+            //     http://abc.net#☃
+            //     
+            //     http://abc.net/foo#☃
+            //
+            // Should be rendered as:
+            //     <p><a href="http://abc.net/%E2%98%83">http://abc.net/☃</a></p>
+            //     <p><a href="http://abc.net?%E2%98%83">http://abc.net?☃</a></p>
+            //     <p><a href="http://abc.net#%E2%98%83">http://abc.net#☃</a></p>
+            //     <p><a href="http://abc.net/foo#%E2%98%83">http://abc.net/foo#☃</a></p>
+
+            TestParser.TestSpec("http://abc.net/☃\n\nhttp://abc.net?☃\n\nhttp://abc.net#☃\n\nhttp://abc.net/foo#☃", "<p><a href=\"http://abc.net/%E2%98%83\">http://abc.net/☃</a></p>\n<p><a href=\"http://abc.net?%E2%98%83\">http://abc.net?☃</a></p>\n<p><a href=\"http://abc.net#%E2%98%83\">http://abc.net#☃</a></p>\n<p><a href=\"http://abc.net/foo#%E2%98%83\">http://abc.net/foo#☃</a></p>", "autolinks|advanced", context: "Example 21\nSection Extensions / AutoLinks / Unicode support\n");
+        }
+
+        // Unicode characters in the FQDN are matched and IDNA encoded
+        [Test]
+        public void ExtensionsAutoLinksUnicodeSupport_Example022()
+        {
+            // Example 22
+            // Section: Extensions / AutoLinks / Unicode support
+            //
+            // The following Markdown:
+            //     http://☃.net?☃
+            //
+            // Should be rendered as:
+            //     <p><a href="http://xn--n3h.net?%E2%98%83">http://☃.net?☃</a></p>
+
+            TestParser.TestSpec("http://☃.net?☃", "<p><a href=\"http://xn--n3h.net?%E2%98%83\">http://☃.net?☃</a></p>", "autolinks|advanced", context: "Example 22\nSection Extensions / AutoLinks / Unicode support\n");
+        }
+
+        // Same goes for regular autolinks
+        [Test]
+        public void ExtensionsAutoLinksUnicodeSupport_Example023()
+        {
+            // Example 23
+            // Section: Extensions / AutoLinks / Unicode support
+            //
+            // The following Markdown:
+            //     <http://abc.net/☃>
+            //     
+            //     <http://abc.net?☃>
+            //     
+            //     <http://abc.net#☃>
+            //     
+            //     <http://abc.net/foo#☃>
+            //
+            // Should be rendered as:
+            //     <p><a href="http://abc.net/%E2%98%83">http://abc.net/☃</a></p>
+            //     <p><a href="http://abc.net?%E2%98%83">http://abc.net?☃</a></p>
+            //     <p><a href="http://abc.net#%E2%98%83">http://abc.net#☃</a></p>
+            //     <p><a href="http://abc.net/foo#%E2%98%83">http://abc.net/foo#☃</a></p>
+
+            TestParser.TestSpec("<http://abc.net/☃>\n\n<http://abc.net?☃>\n\n<http://abc.net#☃>\n\n<http://abc.net/foo#☃>", "<p><a href=\"http://abc.net/%E2%98%83\">http://abc.net/☃</a></p>\n<p><a href=\"http://abc.net?%E2%98%83\">http://abc.net?☃</a></p>\n<p><a href=\"http://abc.net#%E2%98%83\">http://abc.net#☃</a></p>\n<p><a href=\"http://abc.net/foo#%E2%98%83\">http://abc.net/foo#☃</a></p>", "autolinks|advanced", context: "Example 23\nSection Extensions / AutoLinks / Unicode support\n");
+        }
+
+        [Test]
+        public void ExtensionsAutoLinksUnicodeSupport_Example024()
+        {
+            // Example 24
+            // Section: Extensions / AutoLinks / Unicode support
+            //
+            // The following Markdown:
+            //     <http://☃.net?☃>
+            //
+            // Should be rendered as:
+            //     <p><a href="http://xn--n3h.net?%E2%98%83">http://☃.net?☃</a></p>
+
+            TestParser.TestSpec("<http://☃.net?☃>", "<p><a href=\"http://xn--n3h.net?%E2%98%83\">http://☃.net?☃</a></p>", "autolinks|advanced", context: "Example 24\nSection Extensions / AutoLinks / Unicode support\n");
+        }
+
+        // It also complies with CommonMark's vision of priority.
+        // This will therefore be seen as an autolink and not as code inline.
+        [Test]
+        public void ExtensionsAutoLinksUnicodeSupport_Example025()
+        {
+            // Example 25
+            // Section: Extensions / AutoLinks / Unicode support
+            //
+            // The following Markdown:
+            //     <http://foö.bar.`baz>`
+            //
+            // Should be rendered as:
+            //     <p><a href="http://xn--fo-gka.bar.%60baz">http://foö.bar.`baz</a>`</p>
+
+            TestParser.TestSpec("<http://foö.bar.`baz>`", "<p><a href=\"http://xn--fo-gka.bar.%60baz\">http://foö.bar.`baz</a>`</p>", "autolinks|advanced", context: "Example 25\nSection Extensions / AutoLinks / Unicode support\n");
+        }
+
+        // Unicode punctuation characters are not allowed, but symbols are.
+        // Note that this does _not_ exactly match CommonMark's "Unicode punctuation character" definition.
+        [Test]
+        public void ExtensionsAutoLinksUnicodeSupport_Example026()
+        {
+            // Example 26
+            // Section: Extensions / AutoLinks / Unicode support
+            //
+            // The following Markdown:
+            //     http://☃.net?☃ // OtherSymbol
+            //     
+            //     http://🍉.net?🍉 // A UTF-16 surrogate pair, but code point is OtherSymbol
+            //     
+            //     http://‰.net?‰ // OtherPunctuation
+            //
+            // Should be rendered as:
+            //     <p><a href="http://xn--n3h.net?%E2%98%83">http://☃.net?☃</a> // OtherSymbol</p>
+            //     <p><a href="http://xn--ji8h.net?%F0%9F%8D%89">http://🍉.net?🍉</a> // A UTF-16 surrogate pair, but code point is OtherSymbol</p>
+            //     <p>http://‰.net?‰ // OtherPunctuation</p>
+
+            TestParser.TestSpec("http://☃.net?☃ // OtherSymbol\n\nhttp://🍉.net?🍉 // A UTF-16 surrogate pair, but code point is OtherSymbol\n\nhttp://‰.net?‰ // OtherPunctuation", "<p><a href=\"http://xn--n3h.net?%E2%98%83\">http://☃.net?☃</a> // OtherSymbol</p>\n<p><a href=\"http://xn--ji8h.net?%F0%9F%8D%89\">http://🍉.net?🍉</a> // A UTF-16 surrogate pair, but code point is OtherSymbol</p>\n<p>http://‰.net?‰ // OtherPunctuation</p>", "autolinks|advanced", context: "Example 26\nSection Extensions / AutoLinks / Unicode support\n");
+        }
+    }
+}

src/Markdig.Tests/Specs/AutoLinks.md

@@ -0,0 +1,321 @@
+# Extensions
+
+This section describes the different extensions supported:
+
+## AutoLinks
+
+Autolinks will format as a HTML link any string that starts by:
+
+- `http://` or `https://` 
+- `ftp://`
+- `mailto:`
+- `tel:`
+- `www.` 
+ 
+```````````````````````````````` example
+This is a http://www.google.com URL and https://www.google.com
+This is a ftp://test.com
+And a mailto:email@toto.com
+And a tel:+1555123456
+And a plain www.google.com
+.
+<p>This is a <a href="http://www.google.com">http://www.google.com</a> URL and <a href="https://www.google.com">https://www.google.com</a>
+This is a <a href="ftp://test.com">ftp://test.com</a>
+And a <a href="mailto:email@toto.com">email@toto.com</a>
+And a <a href="tel:+1555123456">+1555123456</a>
+And a plain <a href="http://www.google.com">www.google.com</a></p>
+````````````````````````````````
+
+But incomplete links will not be matched:
+ 
+```````````````````````````````` example
+This is not a http:/www.google.com URL and https:/www.google.com
+This is not a ftp:/test.com
+And not a mailto:emailtoto.com
+And not a plain www. or a www.x 
+And not a tel:
+.
+<p>This is not a http:/www.google.com URL and https:/www.google.com
+This is not a ftp:/test.com
+And not a mailto:emailtoto.com
+And not a plain www. or a www.x
+And not a tel:</p>
+````````````````````````````````
+
+Previous character must be a punctuation or a valid space (tab, space, new line):
+ 
+```````````````````````````````` example
+This is not a nhttp://www.google.com URL but this is (https://www.google.com)
+.
+<p>This is not a nhttp://www.google.com URL but this is (<a href="https://www.google.com">https://www.google.com</a>)</p>
+````````````````````````````````
+
+An autolink should not interfere with an `<a>` HTML inline:
+ 
+```````````````````````````````` example
+This is an HTML <a href="http://www.google.com">http://www.google.com</a> link
+.
+<p>This is an HTML <a href="http://www.google.com">http://www.google.com</a> link</p>
+````````````````````````````````
+or even within emphasis:
+ 
+```````````````````````````````` example
+This is an HTML <a href="http://www.google.com"> **http://www.google.com** </a> link
+.
+<p>This is an HTML <a href="http://www.google.com"> <strong>http://www.google.com</strong> </a> link</p>
+````````````````````````````````
+
+
+An autolink should not interfere with a markdown link:
+ 
+```````````````````````````````` example
+This is an HTML [http://www.google.com](http://www.google.com) link
+.
+<p>This is an HTML <a href="http://www.google.com">http://www.google.com</a> link</p>
+````````````````````````````````
+
+A link embraced by pending emphasis should let the emphasis takes precedence if characters are placed at the end of the matched link:
+ 
+```````````````````````````````` example
+Check **http://www.a.com** or __http://www.b.com__
+.
+<p>Check <strong><a href="http://www.a.com">http://www.a.com</a></strong> or <strong><a href="http://www.b.com">http://www.b.com</a></strong></p>
+````````````````````````````````
+
+It is not mentioned by the spec, but empty emails won't be matched (only a subset of [RFC2368](https://tools.ietf.org/html/rfc2368) is supported by auto links):
+
+```````````````````````````````` example
+mailto:email@test.com is okay, but mailto:@test.com is not
+.
+<p><a href="mailto:email@test.com">email@test.com</a> is okay, but mailto:@test.com is not</p>
+````````````````````````````````
+
+### GFM Support
+
+Extract from [GFM Autolinks extensions specs](https://github.github.com/gfm/#autolinks-extension-)
+
+```````````````````````````````` example
+www.commonmark.org
+.
+<p><a href="http://www.commonmark.org">www.commonmark.org</a></p>
+````````````````````````````````
+
+```````````````````````````````` example
+Visit www.commonmark.org/help for more information.
+.
+<p>Visit <a href="http://www.commonmark.org/help">www.commonmark.org/help</a> for more information.</p>
+````````````````````````````````
+
+```````````````````````````````` example
+Visit www.commonmark.org.
+
+Visit www.commonmark.org/a.b.
+.
+<p>Visit <a href="http://www.commonmark.org">www.commonmark.org</a>.</p>
+<p>Visit <a href="http://www.commonmark.org/a.b">www.commonmark.org/a.b</a>.</p>
+````````````````````````````````
+
+
+```````````````````````````````` example
+www.google.com/search?q=Markup+(business)
+
+(www.google.com/search?q=Markup+(business))
+.
+<p><a href="http://www.google.com/search?q=Markup+(business)">www.google.com/search?q=Markup+(business)</a></p>
+<p>(<a href="http://www.google.com/search?q=Markup+(business)">www.google.com/search?q=Markup+(business)</a>)</p>
+````````````````````````````````
+
+
+```````````````````````````````` example
+www.google.com/search?q=commonmark&hl=en
+
+www.google.com/search?q=commonmark&hl;
+.
+<p><a href="http://www.google.com/search?q=commonmark&amp;hl=en">www.google.com/search?q=commonmark&amp;hl=en</a></p>
+<p><a href="http://www.google.com/search?q=commonmark">www.google.com/search?q=commonmark</a>&amp;hl;</p>
+````````````````````````````````
+
+
+```````````````````````````````` example
+www.commonmark.org/he<lp
+.
+<p><a href="http://www.commonmark.org/he">www.commonmark.org/he</a>&lt;lp</p>
+````````````````````````````````
+
+```````````````````````````````` example
+http://commonmark.org
+
+(Visit https://encrypted.google.com/search?q=Markup+(business))
+
+Anonymous FTP is available at ftp://foo.bar.baz.
+.
+<p><a href="http://commonmark.org">http://commonmark.org</a></p>
+<p>(Visit <a href="https://encrypted.google.com/search?q=Markup+(business)">https://encrypted.google.com/search?q=Markup+(business)</a>)</p>
+<p>Anonymous FTP is available at <a href="ftp://foo.bar.baz">ftp://foo.bar.baz</a>.</p>
+````````````````````````````````
+
+### Valid Domain Tests
+
+Domain names that have empty segments won't be matched
+
+```````````````````````````````` example
+www..
+www..com
+http://test.
+http://.test
+http://.
+http://..
+ftp://test.
+ftp://.test
+mailto:email@test.
+mailto:email@.test
+.
+<p>www..
+www..com
+http://test.
+http://.test
+http://.
+http://..
+ftp://test.
+ftp://.test
+mailto:email@test.
+mailto:email@.test</p>
+````````````````````````````````
+
+Domain names with too few segments won't be matched
+
+```````````````````````````````` example
+www
+www.com
+http://test
+ftp://test
+mailto:email@test
+.
+<p>www
+www.com
+http://test
+ftp://test
+mailto:email@test</p>
+````````````````````````````````
+
+Domain names that contain an underscores in the last two segments won't be matched
+
+```````````````````````````````` example
+www._test.foo.bar is okay, but www._test.foo is not
+
+http://te_st.foo.bar is okay, as is http://test.foo_.bar.foo
+
+But http://te_st.foo, http://test.foo_.bar and http://test._foo are not
+
+ftp://test_.foo.bar is okay, but ftp://test.fo_o is not
+
+mailto:email@_test.foo.bar is okay, but mailto:email@_test.foo is not
+.
+<p><a href="http://www._test.foo.bar">www._test.foo.bar</a> is okay, but www._test.foo is not</p>
+<p><a href="http://te_st.foo.bar">http://te_st.foo.bar</a> is okay, as is <a href="http://test.foo_.bar.foo">http://test.foo_.bar.foo</a></p>
+<p>But http://te_st.foo, http://test.foo_.bar and http://test._foo are not</p>
+<p><a href="ftp://test_.foo.bar">ftp://test_.foo.bar</a> is okay, but ftp://test.fo_o is not</p>
+<p><a href="mailto:email@_test.foo.bar">email@_test.foo.bar</a> is okay, but mailto:email@_test.foo is not</p>
+````````````````````````````````
+
+Domain names that contain invalid characters (not AlphaNumberic, -, _ or .) won't be matched
+
+```````````````````````````````` example
+https://[your-domain]/api
+.
+<p>https://[your-domain]/api</p>
+````````````````````````````````
+
+Domain names followed by ?, : or # instead of / are matched
+
+```````````````````````````````` example
+https://github.com?
+
+https://github.com?a
+
+https://github.com#a
+
+https://github.com:
+
+https://github.com:443
+.
+<p><a href="https://github.com">https://github.com</a>?</p>
+<p><a href="https://github.com?a">https://github.com?a</a></p>
+<p><a href="https://github.com#a">https://github.com#a</a></p>
+<p><a href="https://github.com">https://github.com</a>:</p>
+<p><a href="https://github.com:443">https://github.com:443</a></p>
+````````````````````````````````
+
+### Unicode support
+
+Links with unicode characters in the path / query / fragment are matched and url encoded
+
+```````````````````````````````` example
+http://abc.net/☃
+
+http://abc.net?☃
+
+http://abc.net#☃
+
+http://abc.net/foo#☃
+.
+<p><a href="http://abc.net/%E2%98%83">http://abc.net/☃</a></p>
+<p><a href="http://abc.net?%E2%98%83">http://abc.net?☃</a></p>
+<p><a href="http://abc.net#%E2%98%83">http://abc.net#☃</a></p>
+<p><a href="http://abc.net/foo#%E2%98%83">http://abc.net/foo#☃</a></p>
+````````````````````````````````
+
+Unicode characters in the FQDN are matched and IDNA encoded
+
+```````````````````````````````` example
+http://☃.net?☃
+.
+<p><a href="http://xn--n3h.net?%E2%98%83">http://☃.net?☃</a></p>
+````````````````````````````````
+
+Same goes for regular autolinks
+
+```````````````````````````````` example
+<http://abc.net/☃>
+
+<http://abc.net?☃>
+
+<http://abc.net#☃>
+
+<http://abc.net/foo#☃>
+.
+<p><a href="http://abc.net/%E2%98%83">http://abc.net/☃</a></p>
+<p><a href="http://abc.net?%E2%98%83">http://abc.net?☃</a></p>
+<p><a href="http://abc.net#%E2%98%83">http://abc.net#☃</a></p>
+<p><a href="http://abc.net/foo#%E2%98%83">http://abc.net/foo#☃</a></p>
+````````````````````````````````
+
+```````````````````````````````` example
+<http://☃.net?☃>
+.
+<p><a href="http://xn--n3h.net?%E2%98%83">http://☃.net?☃</a></p>
+````````````````````````````````
+
+It also complies with CommonMark's vision of priority.
+This will therefore be seen as an autolink and not as code inline.
+
+```````````````````````````````` example
+<http://foö.bar.`baz>`
+.
+<p><a href="http://xn--fo-gka.bar.%60baz">http://foö.bar.`baz</a>`</p>
+````````````````````````````````
+
+Unicode punctuation characters are not allowed, but symbols are.
+Note that this does _not_ exactly match CommonMark's "Unicode punctuation character" definition.
+
+```````````````````````````````` example
+http://☃.net?☃ // OtherSymbol
+
+http://🍉.net?🍉 // A UTF-16 surrogate pair, but code point is OtherSymbol
+
+http://‰.net?‰ // OtherPunctuation
+.
+<p><a href="http://xn--n3h.net?%E2%98%83">http://☃.net?☃</a> // OtherSymbol</p>
+<p><a href="http://xn--ji8h.net?%F0%9F%8D%89">http://🍉.net?🍉</a> // A UTF-16 surrogate pair, but code point is OtherSymbol</p>
+<p>http://‰.net?‰ // OtherPunctuation</p>
+````````````````````````````````

src/Markdig.Tests/Specs/BootstrapSpecs.generated.cs

@@ -0,0 +1,106 @@
+
+// --------------------------------
+//             Bootstrap
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.Bootstrap
+{
+    [TestFixture]
+    public class TestExtensionsBootstrap
+    {
+        // # Extensions
+        // 
+        // Adds support for outputting bootstrap ready tags:
+        // 
+        // ## Bootstrap
+        //  
+        // Adds bootstrap `.table` class to `<table>`:
+        [Test]
+        public void ExtensionsBootstrap_Example001()
+        {
+            // Example 1
+            // Section: Extensions / Bootstrap
+            //
+            // The following Markdown:
+            //     Name | Value
+            //     -----| -----
+            //     Abc  | 16
+            //
+            // Should be rendered as:
+            //     <table class="table">
+            //     <thead>
+            //     <tr>
+            //     <th>Name</th>
+            //     <th>Value</th>
+            //     </tr>
+            //     </thead>
+            //     <tbody>
+            //     <tr>
+            //     <td>Abc</td>
+            //     <td>16</td>
+            //     </tr>
+            //     </tbody>
+            //     </table>
+
+            TestParser.TestSpec("Name | Value\n-----| -----\nAbc  | 16", "<table class=\"table\">\n<thead>\n<tr>\n<th>Name</th>\n<th>Value</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>Abc</td>\n<td>16</td>\n</tr>\n</tbody>\n</table>", "bootstrap+pipetables+figures+attributes", context: "Example 1\nSection Extensions / Bootstrap\n");
+        }
+
+        // Adds bootstrap `.blockquote` class to `<blockquote>`:
+        [Test]
+        public void ExtensionsBootstrap_Example002()
+        {
+            // Example 2
+            // Section: Extensions / Bootstrap
+            //
+            // The following Markdown:
+            //     > This is a blockquote
+            //
+            // Should be rendered as:
+            //     <blockquote class="blockquote">
+            //     <p>This is a blockquote</p>
+            //     </blockquote>
+
+            TestParser.TestSpec("> This is a blockquote", "<blockquote class=\"blockquote\">\n<p>This is a blockquote</p>\n</blockquote>", "bootstrap+pipetables+figures+attributes", context: "Example 2\nSection Extensions / Bootstrap\n");
+        }
+
+        // Adds bootstrap `.figure` class to `<figure>` and `.figure-caption` to `<figcaption>`
+        [Test]
+        public void ExtensionsBootstrap_Example003()
+        {
+            // Example 3
+            // Section: Extensions / Bootstrap
+            //
+            // The following Markdown:
+            //     ^^^
+            //     This is a text in a caption
+            //     ^^^ This is the caption
+            //
+            // Should be rendered as:
+            //     <figure class="figure">
+            //     <p>This is a text in a caption</p>
+            //     <figcaption class="figure-caption">This is the caption</figcaption>
+            //     </figure>
+
+            TestParser.TestSpec("^^^\nThis is a text in a caption\n^^^ This is the caption", "<figure class=\"figure\">\n<p>This is a text in a caption</p>\n<figcaption class=\"figure-caption\">This is the caption</figcaption>\n</figure>", "bootstrap+pipetables+figures+attributes", context: "Example 3\nSection Extensions / Bootstrap\n");
+        }
+
+        // Adds the `.img-fluid` class to all image links `<img>`
+        [Test]
+        public void ExtensionsBootstrap_Example004()
+        {
+            // Example 4
+            // Section: Extensions / Bootstrap
+            //
+            // The following Markdown:
+            //     ![Image Link](/url)
+            //
+            // Should be rendered as:
+            //     <p><img src="/url" class="img-fluid" alt="Image Link" /></p>
+
+            TestParser.TestSpec("![Image Link](/url)", "<p><img src=\"/url\" class=\"img-fluid\" alt=\"Image Link\" /></p>", "bootstrap+pipetables+figures+attributes", context: "Example 4\nSection Extensions / Bootstrap\n");
+        }
+    }
+}

src/Markdig.Tests/Specs/BootstrapSpecs.md

@@ -1,6 +1,6 @@
 # Extensions
 
-Adds support for outputing bootstrap ready tags:
+Adds support for outputting bootstrap ready tags:
 
 ## Bootstrap
  

src/Markdig.Tests/Specs/CustomContainerSpecs.generated.cs

@@ -0,0 +1,201 @@
+
+// --------------------------------
+//         Custom Containers
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.CustomContainers
+{
+    [TestFixture]
+    public class TestExtensionsCustomContainer
+    {
+        // # Extensions
+        // 
+        // This section describes the different extensions supported:
+        // 
+        // ## Custom Container
+        // 
+        // A custom container is similar to a fenced code block, but it is using the character `:` to declare a block (with at least 3 characters), and instead of generating a `<pre><code>...</code></pre>` it will generate a `<div>...</div>` block.
+        [Test]
+        public void ExtensionsCustomContainer_Example001()
+        {
+            // Example 1
+            // Section: Extensions / Custom Container
+            //
+            // The following Markdown:
+            //     :::spoiler
+            //     This is a *spoiler*
+            //     :::
+            //
+            // Should be rendered as:
+            //     <div class="spoiler"><p>This is a <em>spoiler</em></p>
+            //     </div>
+
+            TestParser.TestSpec(":::spoiler\nThis is a *spoiler*\n:::", "<div class=\"spoiler\"><p>This is a <em>spoiler</em></p>\n</div>", "customcontainers+attributes|advanced", context: "Example 1\nSection Extensions / Custom Container\n");
+        }
+
+        // The text following the opened custom container is optional:
+        [Test]
+        public void ExtensionsCustomContainer_Example002()
+        {
+            // Example 2
+            // Section: Extensions / Custom Container
+            //
+            // The following Markdown:
+            //     :::
+            //     This is a regular div
+            //     :::
+            //
+            // Should be rendered as:
+            //     <div><p>This is a regular div</p>
+            //     </div>
+
+            TestParser.TestSpec(":::\nThis is a regular div\n:::", "<div><p>This is a regular div</p>\n</div>", "customcontainers+attributes|advanced", context: "Example 2\nSection Extensions / Custom Container\n");
+        }
+
+        // Like for fenced code block, you can use more than 3 `:` characters as long as the closing has the same number of characters:
+        [Test]
+        public void ExtensionsCustomContainer_Example003()
+        {
+            // Example 3
+            // Section: Extensions / Custom Container
+            //
+            // The following Markdown:
+            //     ::::::::::::spoiler
+            //     This is a spoiler
+            //     ::::::::::::
+            //
+            // Should be rendered as:
+            //     <div class="spoiler"><p>This is a spoiler</p>
+            //     </div>
+
+            TestParser.TestSpec("::::::::::::spoiler\nThis is a spoiler\n::::::::::::", "<div class=\"spoiler\"><p>This is a spoiler</p>\n</div>", "customcontainers+attributes|advanced", context: "Example 3\nSection Extensions / Custom Container\n");
+        }
+
+        // Like for fenced code block, a custom container can span over multiple empty lines in a list block:
+        [Test]
+        public void ExtensionsCustomContainer_Example004()
+        {
+            // Example 4
+            // Section: Extensions / Custom Container
+            //
+            // The following Markdown:
+            //     - This is a list
+            //       :::spoiler
+            //       This is a spoiler
+            //       - item1
+            //       - item2
+            //       :::
+            //     - A second item in the list
+            //
+            // Should be rendered as:
+            //     <ul>
+            //     <li>This is a list
+            //     <div class="spoiler">This is a spoiler
+            //     <ul>
+            //     <li>item1</li>
+            //     <li>item2</li>
+            //     </ul>
+            //     </div>
+            //     </li>
+            //     <li>A second item in the list</li>
+            //     </ul>
+
+            TestParser.TestSpec("- This is a list\n  :::spoiler\n  This is a spoiler\n  - item1\n  - item2\n  :::\n- A second item in the list", "<ul>\n<li>This is a list\n<div class=\"spoiler\">This is a spoiler\n<ul>\n<li>item1</li>\n<li>item2</li>\n</ul>\n</div>\n</li>\n<li>A second item in the list</li>\n</ul>", "customcontainers+attributes|advanced", context: "Example 4\nSection Extensions / Custom Container\n");
+        }
+
+        // Attributes extension is also supported for Custom Container, as long as the Attributes extension is activated after the CustomContainer extension (`.UseCustomContainer().UseAttributes()`)
+        [Test]
+        public void ExtensionsCustomContainer_Example005()
+        {
+            // Example 5
+            // Section: Extensions / Custom Container
+            //
+            // The following Markdown:
+            //     :::spoiler {#myspoiler myprop=yes}
+            //     This is a spoiler
+            //     :::
+            //
+            // Should be rendered as:
+            //     <div id="myspoiler" class="spoiler" myprop="yes"><p>This is a spoiler</p>
+            //     </div>
+
+            TestParser.TestSpec(":::spoiler {#myspoiler myprop=yes}\nThis is a spoiler\n:::", "<div id=\"myspoiler\" class=\"spoiler\" myprop=\"yes\"><p>This is a spoiler</p>\n</div>", "customcontainers+attributes|advanced", context: "Example 5\nSection Extensions / Custom Container\n");
+        }
+
+        // The content of a custom container can contain any blocks:
+        [Test]
+        public void ExtensionsCustomContainer_Example006()
+        {
+            // Example 6
+            // Section: Extensions / Custom Container
+            //
+            // The following Markdown:
+            //     :::mycontainer
+            //     <p>This is a raw spoiler</p>
+            //     :::
+            //
+            // Should be rendered as:
+            //     <div class="mycontainer"><p>This is a raw spoiler</p>
+            //     </div>
+
+            TestParser.TestSpec(":::mycontainer\n<p>This is a raw spoiler</p>\n:::", "<div class=\"mycontainer\"><p>This is a raw spoiler</p>\n</div>", "customcontainers+attributes|advanced", context: "Example 6\nSection Extensions / Custom Container\n");
+        }
+    }
+
+    [TestFixture]
+    public class TestExtensionsInlineCustomContainer
+    {
+        // ## Inline Custom Container 
+        // 
+        // A custom container can also be used within an inline container (e.g: paragraph, heading...) by enclosing a text by a new emphasis `::`
+        [Test]
+        public void ExtensionsInlineCustomContainer_Example007()
+        {
+            // Example 7
+            // Section: Extensions / Inline Custom Container 
+            //
+            // The following Markdown:
+            //     This is a text ::with special emphasis::
+            //
+            // Should be rendered as:
+            //     <p>This is a text <span>with special emphasis</span></p>
+
+            TestParser.TestSpec("This is a text ::with special emphasis::", "<p>This is a text <span>with special emphasis</span></p>", "customcontainers+attributes|advanced", context: "Example 7\nSection Extensions / Inline Custom Container \n");
+        }
+
+        // Any other emphasis inline can be used within this emphasis inline container:
+        [Test]
+        public void ExtensionsInlineCustomContainer_Example008()
+        {
+            // Example 8
+            // Section: Extensions / Inline Custom Container 
+            //
+            // The following Markdown:
+            //     This is a text ::with special *emphasis*::
+            //
+            // Should be rendered as:
+            //     <p>This is a text <span>with special <em>emphasis</em></span></p>
+
+            TestParser.TestSpec("This is a text ::with special *emphasis*::", "<p>This is a text <span>with special <em>emphasis</em></span></p>", "customcontainers+attributes|advanced", context: "Example 8\nSection Extensions / Inline Custom Container \n");
+        }
+
+        // Attributes can be attached to a inline custom container:
+        [Test]
+        public void ExtensionsInlineCustomContainer_Example009()
+        {
+            // Example 9
+            // Section: Extensions / Inline Custom Container 
+            //
+            // The following Markdown:
+            //     This is a text ::with special emphasis::{#myId .myemphasis}
+            //
+            // Should be rendered as:
+            //     <p>This is a text <span id="myId" class="myemphasis">with special emphasis</span></p>
+
+            TestParser.TestSpec("This is a text ::with special emphasis::{#myId .myemphasis}", "<p>This is a text <span id=\"myId\" class=\"myemphasis\">with special emphasis</span></p>", "customcontainers+attributes|advanced", context: "Example 9\nSection Extensions / Inline Custom Container \n");
+        }
+    }
+}

src/Markdig.Tests/Specs/CustomContainerSpecs.md

@@ -4,7 +4,7 @@ This section describes the different extensions supported:
 
 ## Custom Container
 
-A custom container is similar to a fenced code block, but it is using the character `:` to declare a block (with at least 3 characters), and instead of generating a `<pre><code>...</code></pre>` it will generate a `<div>...</dib>` block.
+A custom container is similar to a fenced code block, but it is using the character `:` to declare a block (with at least 3 characters), and instead of generating a `<pre><code>...</code></pre>` it will generate a `<div>...</div>` block.
 
 ```````````````````````````````` example
 :::spoiler
@@ -109,4 +109,4 @@ Attributes can be attached to a inline custom container:
 This is a text ::with special emphasis::{#myId .myemphasis}
 .
 <p>This is a text <span id="myId" class="myemphasis">with special emphasis</span></p>
-````````````````````````````````
+````````````````````````````````

src/Markdig.Tests/Specs/DefinitionListSpecs.generated.cs

@@ -0,0 +1,195 @@
+
+// --------------------------------
+//         Definition Lists
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.DefinitionLists
+{
+    [TestFixture]
+    public class TestExtensionsDefinitionLists
+    {
+        // # Extensions
+        // 
+        // This section describes the different extensions supported:
+        // 
+        // ## Definition lists
+        // 
+        // A custom container is similar to a fenced code block, but it is using the character `:` to declare a block (with at least 3 characters), and instead of generating a `<pre><code>...</code></pre>` it will generate a `<div>...</div>` block.
+        [Test]
+        public void ExtensionsDefinitionLists_Example001()
+        {
+            // Example 1
+            // Section: Extensions / Definition lists
+            //
+            // The following Markdown:
+            //     
+            //     Term 1
+            //     :   This is a definition item
+            //         With a paragraph
+            //         > This is a block quote
+            //     
+            //         - This is a list
+            //         - with an item2
+            //     
+            //         ```java
+            //         Test
+            //     
+            //     
+            //         ```
+            //     
+            //         And a last line
+            //     :   This ia another definition item
+            //     
+            //     Term2
+            //     Term3 *with some inline*
+            //     :   This is another definition for term2
+            //
+            // Should be rendered as:
+            //     <dl>
+            //     <dt>Term 1</dt>
+            //     <dd><p>This is a definition item
+            //     With a paragraph</p>
+            //     <blockquote>
+            //     <p>This is a block quote</p>
+            //     </blockquote>
+            //     <ul>
+            //     <li>This is a list</li>
+            //     <li>with an item2</li>
+            //     </ul>
+            //     <pre><code class="language-java">Test
+            //     
+            //     
+            //     </code></pre>
+            //     <p>And a last line</p>
+            //     </dd>
+            //     <dd>This ia another definition item</dd>
+            //     <dt>Term2</dt>
+            //     <dt>Term3 <em>with some inline</em></dt>
+            //     <dd>This is another definition for term2</dd>
+            //     </dl>
+
+            TestParser.TestSpec("\nTerm 1\n:   This is a definition item\n    With a paragraph\n    > This is a block quote\n\n    - This is a list\n    - with an item2\n\n    ```java\n    Test\n\n\n    ```\n\n    And a last line\n:   This ia another definition item\n\nTerm2\nTerm3 *with some inline*\n:   This is another definition for term2", "<dl>\n<dt>Term 1</dt>\n<dd><p>This is a definition item\nWith a paragraph</p>\n<blockquote>\n<p>This is a block quote</p>\n</blockquote>\n<ul>\n<li>This is a list</li>\n<li>with an item2</li>\n</ul>\n<pre><code class=\"language-java\">Test\n\n\n</code></pre>\n<p>And a last line</p>\n</dd>\n<dd>This ia another definition item</dd>\n<dt>Term2</dt>\n<dt>Term3 <em>with some inline</em></dt>\n<dd>This is another definition for term2</dd>\n</dl>", "definitionlists+attributes|advanced", context: "Example 1\nSection Extensions / Definition lists\n");
+        }
+
+        // A definition term can be followed at most by one blank line. Lazy continuations are supported for definitions:
+        [Test]
+        public void ExtensionsDefinitionLists_Example002()
+        {
+            // Example 2
+            // Section: Extensions / Definition lists
+            //
+            // The following Markdown:
+            //     Term 1
+            //     
+            //     :   Definition
+            //     with lazy continuation.
+            //     
+            //         Second paragraph of the definition.
+            //
+            // Should be rendered as:
+            //     <dl>
+            //     <dt>Term 1</dt>
+            //     <dd><p>Definition
+            //     with lazy continuation.</p>
+            //     <p>Second paragraph of the definition.</p>
+            //     </dd>
+            //     </dl>
+
+            TestParser.TestSpec("Term 1\n\n:   Definition\nwith lazy continuation.\n\n    Second paragraph of the definition.", "<dl>\n<dt>Term 1</dt>\n<dd><p>Definition\nwith lazy continuation.</p>\n<p>Second paragraph of the definition.</p>\n</dd>\n</dl>", "definitionlists+attributes|advanced", context: "Example 2\nSection Extensions / Definition lists\n");
+        }
+
+        // The definition must be indented to 4 characters including the `:`. 
+        [Test]
+        public void ExtensionsDefinitionLists_Example003()
+        {
+            // Example 3
+            // Section: Extensions / Definition lists
+            //
+            // The following Markdown:
+            //     Term 1
+            //     :  Invalid with less than 3 characters
+            //
+            // Should be rendered as:
+            //     <p>Term 1
+            //     :  Invalid with less than 3 characters</p>
+
+            TestParser.TestSpec("Term 1\n:  Invalid with less than 3 characters", "<p>Term 1\n:  Invalid with less than 3 characters</p>", "definitionlists+attributes|advanced", context: "Example 3\nSection Extensions / Definition lists\n");
+        }
+
+        // The `:` can be indented up to 3 spaces:
+        [Test]
+        public void ExtensionsDefinitionLists_Example004()
+        {
+            // Example 4
+            // Section: Extensions / Definition lists
+            //
+            // The following Markdown:
+            //     Term 1
+            //        : Valid even if `:` starts at most 3 spaces
+            //
+            // Should be rendered as:
+            //     <dl>
+            //     <dt>Term 1</dt>
+            //     <dd>Valid even if <code>:</code> starts at most 3 spaces</dd>
+            //     </dl>
+
+            TestParser.TestSpec("Term 1\n   : Valid even if `:` starts at most 3 spaces", "<dl>\n<dt>Term 1</dt>\n<dd>Valid even if <code>:</code> starts at most 3 spaces</dd>\n</dl>", "definitionlists+attributes|advanced", context: "Example 4\nSection Extensions / Definition lists\n");
+        }
+
+        // But more than 3 spaces before `:` will trigger an indented code block:
+        [Test]
+        public void ExtensionsDefinitionLists_Example005()
+        {
+            // Example 5
+            // Section: Extensions / Definition lists
+            //
+            // The following Markdown:
+            //     Term 1
+            //     
+            //         : Not valid
+            //
+            // Should be rendered as:
+            //     <p>Term 1</p>
+            //     <pre><code>: Not valid
+            //     </code></pre>
+
+            TestParser.TestSpec("Term 1\n\n    : Not valid", "<p>Term 1</p>\n<pre><code>: Not valid\n</code></pre>", "definitionlists+attributes|advanced", context: "Example 5\nSection Extensions / Definition lists\n");
+        }
+
+        // Definition lists can be nested inside list items
+        [Test]
+        public void ExtensionsDefinitionLists_Example006()
+        {
+            // Example 6
+            // Section: Extensions / Definition lists
+            //
+            // The following Markdown:
+            //     1.  First
+            //         
+            //     2.  Second
+            //         
+            //         Term 1
+            //         :   Definition
+            //         
+            //         Term 2
+            //         :   Second Definition
+            //
+            // Should be rendered as:
+            //     <ol>
+            //     <li><p>First</p></li>
+            //     <li><p>Second</p>
+            //     <dl>
+            //     <dt>Term 1</dt>
+            //     <dd>Definition</dd>
+            //     <dt>Term 2</dt>
+            //     <dd>Second Definition</dd>
+            //     </dl></li>
+            //     </ol>
+
+            TestParser.TestSpec("1.  First\n    \n2.  Second\n    \n    Term 1\n    :   Definition\n    \n    Term 2\n    :   Second Definition", "<ol>\n<li><p>First</p></li>\n<li><p>Second</p>\n<dl>\n<dt>Term 1</dt>\n<dd>Definition</dd>\n<dt>Term 2</dt>\n<dd>Second Definition</dd>\n</dl></li>\n</ol>", "definitionlists+attributes|advanced", context: "Example 6\nSection Extensions / Definition lists\n");
+        }
+    }
+}

src/Markdig.Tests/Specs/DefinitionListSpecs.md

@@ -4,7 +4,7 @@ This section describes the different extensions supported:
 
 ## Definition lists
 
-A custom container is similar to a fenced code block, but it is using the character `:` to declare a block (with at least 3 characters), and instead of generating a `<pre><code>...</code></pre>` it will generate a `<div>...</dib>` block.
+A custom container is similar to a fenced code block, but it is using the character `:` to declare a block (with at least 3 characters), and instead of generating a `<pre><code>...</code></pre>` it will generate a `<div>...</div>` block.
 
 ```````````````````````````````` example
 
@@ -105,3 +105,28 @@ Term 1
 <pre><code>: Not valid
 </code></pre>
 ````````````````````````````````
+
+Definition lists can be nested inside list items
+
+```````````````````````````````` example
+1.  First
+    
+2.  Second
+    
+    Term 1
+    :   Definition
+    
+    Term 2
+    :   Second Definition
+.
+<ol>
+<li><p>First</p></li>
+<li><p>Second</p>
+<dl>
+<dt>Term 1</dt>
+<dd>Definition</dd>
+<dt>Term 2</dt>
+<dd>Second Definition</dd>
+</dl></li>
+</ol>
+````````````````````````````````

src/Markdig.Tests/Specs/DiagramsSpecs.generated.cs

@@ -0,0 +1,91 @@
+
+// --------------------------------
+//             Diagrams
+// --------------------------------
+
+using System;
+using NUnit.Framework;
+
+namespace Markdig.Tests.Specs.Diagrams
+{
+    [TestFixture]
+    public class TestExtensionsMermaidDiagrams
+    {
+        // # Extensions
+        // 
+        // Adds support for diagrams extension:
+        // 
+        // ## Mermaid diagrams
+        //  
+        // Using a fenced code block with the `mermaid` language info will output a `<pre class='mermaid'>` block (which is the default for other code block):
+        [Test]
+        public void ExtensionsMermaidDiagrams_Example001()
+        {
+            // Example 1
+            // Section: Extensions / Mermaid diagrams
+            //
+            // The following Markdown:
+            //     ```mermaid
+            //     graph TD;
+            //         A-->B;
+            //         A-->C;
+            //         B-->D;
+            //         C-->D;
+            //     ```
+            //
+            // Should be rendered as:
+            //     <pre class="mermaid">graph TD;
+            //         A-->B;
+            //         A-->C;
+            //         B-->D;
+            //         C-->D;
+            //     </pre>
+
+            TestParser.TestSpec("```mermaid\ngraph TD;\n    A-->B;\n    A-->C;\n    B-->D;\n    C-->D;\n```", "<pre class=\"mermaid\">graph TD;\n    A-->B;\n    A-->C;\n    B-->D;\n    C-->D;\n</pre>", "diagrams|advanced", context: "Example 1\nSection Extensions / Mermaid diagrams\n");
+        }
+    }
+
+    [TestFixture]
+    public class TestExtensionsNomnomlDiagrams
+    {
+        // ## nomnoml diagrams
+        // 
+        // Using a fenced code block with the `nomnoml` language info will output a `<div class='nomnoml'>` instead of a `pre/code` block:
+        [Test]
+        public void ExtensionsNomnomlDiagrams_Example002()
+        {
+            // Example 2
+            // Section: Extensions / nomnoml diagrams
+            //
+            // The following Markdown:
+            //     ```nomnoml
+            //     [example|
+            //       propertyA: Int
+            //       propertyB: string
+            //     |
+            //       methodA()
+            //       methodB()
+            //     |
+            //       [subA]--[subB]
+            //       [subA]-:>[sub C]
+            //     ]
+            //     ```
+            //
+            // Should be rendered as:
+            //     <div class="nomnoml">[example|
+            //       propertyA: Int
+            //       propertyB: string
+            //     |
+            //       methodA()
+            //       methodB()
+            //     |
+            //       [subA]--[subB]
+            //       [subA]-:>[sub C]
+            //     ]
+            //     </div>
+
+            TestParser.TestSpec("```nomnoml\n[example|\n  propertyA: Int\n  propertyB: string\n|\n  methodA()\n  methodB()\n|\n  [subA]--[subB]\n  [subA]-:>[sub C]\n]\n```", "<div class=\"nomnoml\">[example|\n  propertyA: Int\n  propertyB: string\n|\n  methodA()\n  methodB()\n|\n  [subA]--[subB]\n  [subA]-:>[sub C]\n]\n</div>", "diagrams|advanced", context: "Example 2\nSection Extensions / nomnoml diagrams\n");
+        }
+        // TODO: Add other text diagram languages
+    }
+}

src/Markdig.Tests/Specs/DiagramsSpecs.md

@@ -0,0 +1,57 @@
+# Extensions
+
+Adds support for diagrams extension:
+
+## Mermaid diagrams
+ 
+Using a fenced code block with the `mermaid` language info will output a `<pre class='mermaid'>` block (which is the default for other code block):
+
+```````````````````````````````` example
+```mermaid
+graph TD;
+    A-->B;
+    A-->C;
+    B-->D;
+    C-->D;
+```
+.
+<pre class="mermaid">graph TD;
+    A-->B;
+    A-->C;
+    B-->D;
+    C-->D;
+</pre>
+````````````````````````````````
+
+## nomnoml diagrams
+
+Using a fenced code block with the `nomnoml` language info will output a `<div class='nomnoml'>` instead of a `pre/code` block:
+
+```````````````````````````````` example
+```nomnoml
+[example|
+  propertyA: Int
+  propertyB: string
+|
+  methodA()
+  methodB()
+|
+  [subA]--[subB]
+  [subA]-:>[sub C]
+]
+```
+.
+<div class="nomnoml">[example|
+  propertyA: Int
+  propertyB: string
+|
+  methodA()
+  methodB()
+|
+  [subA]--[subB]
+  [subA]-:>[sub C]
+]
+</div>
+````````````````````````````````
+
+TODO: Add other text diagram languages