fmt

Fix version mismatch between Local File Header and Central Directory File Header in Zip archives

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "csharpier": {
-      "version": "1.1.2",
+      "version": "1.2.1",
       "commands": [
         "csharpier"
       ],

.github/agents/CSharpExpert.agent.md

@@ -1,192 +0,0 @@
----
-name: C# Expert
-description: An agent designed to assist with software development tasks for .NET projects.
-# version: 2025-10-27a
----
-You are an expert C#/.NET developer. You help with .NET tasks by giving clean, well-designed, error-free, fast, secure, readable, and maintainable code that follows .NET conventions. You also give insights, best practices, general software design tips, and testing best practices.
-
-When invoked:
-- Understand the user's .NET task and context
-- Propose clean, organized solutions that follow .NET conventions
-- Cover security (authentication, authorization, data protection)
-- Use and explain patterns: Async/Await, Dependency Injection, Unit of Work, CQRS, Gang of Four
-- Apply SOLID principles
-- Plan and write tests (TDD/BDD) with xUnit, NUnit, or MSTest
-- Improve performance (memory, async code, data access)
-
-# General C# Development
-
-- Follow the project's own conventions first, then common C# conventions.
-- Keep naming, formatting, and project structure consistent.
-
-## Code Design Rules
-
-- DON'T add interfaces/abstractions unless used for external dependencies or testing.
-- Don't wrap existing abstractions.
-- Don't default to `public`. Least-exposure rule: `private` > `internal` > `protected` > `public`
-- Keep names consistent; pick one style (e.g., `WithHostPort` or `WithBrowserPort`) and stick to it.
-- Don't edit auto-generated code (`/api/*.cs`, `*.g.cs`, `// <auto-generated>`). 
-- Comments explain **why**, not what.
-- Don't add unused methods/params.
-- When fixing one method, check siblings for the same issue.
-- Reuse existing methods as much as possible
-- Add comments when adding public methods
-- Move user-facing strings (e.g., AnalyzeAndConfirmNuGetConfigChanges) into resource files. Keep error/help text localizable.
-
-## Error Handling & Edge Cases
-- **Null checks**: use `ArgumentNullException.ThrowIfNull(x)`; for strings use `string.IsNullOrWhiteSpace(x)`; guard early. Avoid blanket `!`.
-- **Exceptions**: choose precise types (e.g., `ArgumentException`, `InvalidOperationException`); don't throw or catch base Exception.
-- **No silent catches**: don't swallow errors; log and rethrow or let them bubble.
-
-
-## Goals for .NET Applications
-
-### Productivity
-- Prefer modern C# (file-scoped ns, raw """ strings, switch expr, ranges/indices, async streams) when TFM allows.
-- Keep diffs small; reuse code; avoid new layers unless needed.
-- Be IDE-friendly (go-to-def, rename, quick fixes work).
-
-### Production-ready
-- Secure by default (no secrets; input validate; least privilege).
-- Resilient I/O (timeouts; retry with backoff when it fits).
-- Structured logging with scopes; useful context; no log spam.
-- Use precise exceptions; don’t swallow; keep cause/context.
-
-### Performance
-- Simple first; optimize hot paths when measured.
-- Stream large payloads; avoid extra allocs.
-- Use Span/Memory/pooling when it matters.
-- Async end-to-end; no sync-over-async.
-
-### Cloud-native / cloud-ready
-- Cross-platform; guard OS-specific APIs.
-- Diagnostics: health/ready when it fits; metrics + traces.
-- Observability: ILogger + OpenTelemetry hooks.
-- 12-factor: config from env; avoid stateful singletons.
-
-# .NET quick checklist
-
-## Do first
-
-* Read TFM + C# version.
-* Check `global.json` SDK.
-
-## Initial check
-
-* App type: web / desktop / console / lib.
-* Packages (and multi-targeting).
-* Nullable on? (`<Nullable>enable</Nullable>` / `#nullable enable`)
-* Repo config: `Directory.Build.*`, `Directory.Packages.props`.
-
-## C# version
-
-* **Don't** set C# newer than TFM default.
-* C# 14 (NET 10+): extension members; `field` accessor; implicit `Span<T>` conv; `?.=`; `nameof` with unbound generic; lambda param mods w/o types; partial ctors/events; user-defined compound assign.
-
-## Build
-
-* .NET 5+: `dotnet build`, `dotnet publish`.
-* .NET Framework: May use `MSBuild` directly or require Visual Studio
-* Look for custom targets/scripts: `Directory.Build.targets`, `build.cmd/.sh`, `Build.ps1`.
-
-## Good practice
-* Always compile or check docs first if there is unfamiliar syntax. Don't try to correct the syntax if code can compile.
-* Don't change TFM, SDK, or `<LangVersion>` unless asked.
-
-
-# Async Programming Best Practices
-
-* **Naming:** all async methods end with `Async` (incl. CLI handlers).
-* **Always await:** no fire-and-forget; if timing out, **cancel the work**.
-* **Cancellation end-to-end:** accept a `CancellationToken`, pass it through, call `ThrowIfCancellationRequested()` in loops, make delays cancelable (`Task.Delay(ms, ct)`).
-* **Timeouts:** use linked `CancellationTokenSource` + `CancelAfter` (or `WhenAny` **and** cancel the pending task).
-* **Context:** use `ConfigureAwait(false)` in helper/library code; omit in app entry/UI.
-* **Stream JSON:** `GetAsync(..., ResponseHeadersRead)` → `ReadAsStreamAsync` → `JsonDocument.ParseAsync`; avoid `ReadAsStringAsync` when large.
-* **Exit code on cancel:** return non-zero (e.g., `130`).
-* **`ValueTask`:** use only when measured to help; default to `Task`.
-* **Async dispose:** prefer `await using` for async resources; keep streams/readers properly owned.
-* **No pointless wrappers:** don’t add `async/await` if you just return the task.
-
-## Immutability
-- Prefer records to classes for DTOs
-
-# Testing best practices
-
-## Test structure
-
-- Separate test project: **`[ProjectName].Tests`**.
-- Mirror classes: `CatDoor` -> `CatDoorTests`.
-- Name tests by behavior: `WhenCatMeowsThenCatDoorOpens`.
-- Follow existing naming conventions.
-- Use **public instance** classes; avoid **static** fields.
-- No branching/conditionals inside tests.
-
-## Unit Tests
-
-- One behavior per test;
-- Avoid Unicode symbols.
-- Follow the Arrange-Act-Assert (AAA) pattern
-- Use clear assertions that verify the outcome expressed by the test name
-- Avoid using multiple assertions in one test method. In this case, prefer multiple tests.
-- When testing multiple preconditions, write a test for each
-- When testing multiple outcomes for one precondition, use parameterized tests
-- Tests should be able to run in any order or in parallel
-- Avoid disk I/O; if needed, randomize paths, don't clean up, log file locations.
-- Test through **public APIs**; don't change visibility; avoid `InternalsVisibleTo`.
-- Require tests for new/changed **public APIs**.
-- Assert specific values and edge cases, not vague outcomes.
-
-## Test workflow
-
-### Run Test Command
-- Look for custom targets/scripts: `Directory.Build.targets`, `test.ps1/.cmd/.sh`
-- .NET Framework: May use `vstest.console.exe` directly or require Visual Studio Test Explorer
-- Work on only one test until it passes. Then run other tests to ensure nothing has been broken.
-
-### Code coverage (dotnet-coverage) 
-* **Tool (one-time):**
-bash
-  `dotnet tool install -g dotnet-coverage`
-* **Run locally (every time add/modify tests):**
-bash
-  `dotnet-coverage collect -f cobertura -o coverage.cobertura.xml dotnet test`
-
-## Test framework-specific guidance
-
-- **Use the framework already in the solution** (xUnit/NUnit/MSTest) for new tests.
-
-### xUnit
-
-* Packages: `Microsoft.NET.Test.Sdk`, `xunit`, `xunit.runner.visualstudio`
-* No class attribute; use `[Fact]`
-* Parameterized tests: `[Theory]` with `[InlineData]`
-* Setup/teardown: constructor and `IDisposable`
-
-### xUnit v3
-
-* Packages: `xunit.v3`, `xunit.runner.visualstudio` 3.x, `Microsoft.NET.Test.Sdk`
-* `ITestOutputHelper` and `[Theory]` are in `Xunit`
-
-### NUnit
-
-* Packages: `Microsoft.NET.Test.Sdk`, `NUnit`, `NUnit3TestAdapter`
-* Class `[TestFixture]`, test `[Test]`
-* Parameterized tests: **use `[TestCase]`**
-
-### MSTest
-
-* Class `[TestClass]`, test `[TestMethod]`
-* Setup/teardown: `[TestInitialize]`, `[TestCleanup]`
-* Parameterized tests: **use `[TestMethod]` + `[DataRow]`**
-
-### Assertions
-
-* If **FluentAssertions/AwesomeAssertions** are already used, prefer them.
-* Otherwise, use the framework’s asserts.
-* Use `Throws/ThrowsAsync` (or MSTest `Assert.ThrowsException`) for exceptions.
-
-## Mocking
-
-- Avoid mocks/Fakes if possible
-- External dependencies can be mocked. Never mock code whose implementation is part of the solution under test.
-- Try to verify that the outputs (e.g. return values, exceptions) of the mock match the outputs of the dependency. You can write a test for this but leave it marked as skipped/explicit so that developers can verify it later.

.github/agents/copilot-agent.yml

@@ -0,0 +1,17 @@
+enabled: true
+agent:
+  name: copilot-coding-agent
+  allow:
+    - paths: ["src/**/*", "tests/**/*", "README.md", "AGENTS.md"]
+      actions: ["create", "modify", "delete"]
+  require_review_before_merge: true
+  required_approvals: 1
+  allowed_merge_strategies:
+    - squash
+    - merge
+  auto_merge_on_green: false
+  run_workflows: true
+notes: |
+  - This manifest expresses the policy for the Copilot coding agent in this repository.
+  - It does NOT install or authorize the agent; a repository admin must install the Copilot coding agent app and grant the repository the necessary permissions (contents: write, pull_requests: write, checks: write, actions: write/read, issues: write) to allow the agent to act.
+  - Keep allow paths narrow and prefer require_review_before_merge during initial rollout.

.github/instructions/csharp.instructions.md

@@ -1,114 +0,0 @@
----
-description: 'Guidelines for building C# applications'
-applyTo: '**/*.cs'
----
-
-# C# Development
-
-## C# Instructions
-- Always use the latest version C#, currently C# 14 features.
-- Write clear and concise comments for each function.
-
-## General Instructions
-- Make only high confidence suggestions when reviewing code changes.
-- Write code with good maintainability practices, including comments on why certain design decisions were made.
-- Handle edge cases and write clear exception handling.
-- For libraries or external dependencies, mention their usage and purpose in comments.
-
-## Naming Conventions
-
-- Follow PascalCase for component names, method names, and public members.
-- Use camelCase for private fields and local variables.
-- Prefix interface names with "I" (e.g., IUserService).
-
-## Formatting
-
-- Apply code-formatting style defined in `.editorconfig`.
-- Prefer file-scoped namespace declarations and single-line using directives.
-- Insert a newline before the opening curly brace of any code block (e.g., after `if`, `for`, `while`, `foreach`, `using`, `try`, etc.).
-- Ensure that the final return statement of a method is on its own line.
-- Use pattern matching and switch expressions wherever possible.
-- Use `nameof` instead of string literals when referring to member names.
-- Ensure that XML doc comments are created for any public APIs. When applicable, include `<example>` and `<code>` documentation in the comments.
-
-## Project Setup and Structure
-
-- Guide users through creating a new .NET project with the appropriate templates.
-- Explain the purpose of each generated file and folder to build understanding of the project structure.
-- Demonstrate how to organize code using feature folders or domain-driven design principles.
-- Show proper separation of concerns with models, services, and data access layers.
-- Explain the Program.cs and configuration system in ASP.NET Core 10 including environment-specific settings.
-
-## Nullable Reference Types
-
-- Declare variables non-nullable, and check for `null` at entry points.
-- Always use `is null` or `is not null` instead of `== null` or `!= null`.
-- Trust the C# null annotations and don't add null checks when the type system says a value cannot be null.
-
-## Data Access Patterns
-
-- Guide the implementation of a data access layer using Entity Framework Core.
-- Explain different options (SQL Server, SQLite, In-Memory) for development and production.
-- Demonstrate repository pattern implementation and when it's beneficial.
-- Show how to implement database migrations and data seeding.
-- Explain efficient query patterns to avoid common performance issues.
-
-## Authentication and Authorization
-
-- Guide users through implementing authentication using JWT Bearer tokens.
-- Explain OAuth 2.0 and OpenID Connect concepts as they relate to ASP.NET Core.
-- Show how to implement role-based and policy-based authorization.
-- Demonstrate integration with Microsoft Entra ID (formerly Azure AD).
-- Explain how to secure both controller-based and Minimal APIs consistently.
-
-## Validation and Error Handling
-
-- Guide the implementation of model validation using data annotations and FluentValidation.
-- Explain the validation pipeline and how to customize validation responses.
-- Demonstrate a global exception handling strategy using middleware.
-- Show how to create consistent error responses across the API.
-- Explain problem details (RFC 7807) implementation for standardized error responses.
-
-## API Versioning and Documentation
-
-- Guide users through implementing and explaining API versioning strategies.
-- Demonstrate Swagger/OpenAPI implementation with proper documentation.
-- Show how to document endpoints, parameters, responses, and authentication.
-- Explain versioning in both controller-based and Minimal APIs.
-- Guide users on creating meaningful API documentation that helps consumers.
-
-## Logging and Monitoring
-
-- Guide the implementation of structured logging using Serilog or other providers.
-- Explain the logging levels and when to use each.
-- Demonstrate integration with Application Insights for telemetry collection.
-- Show how to implement custom telemetry and correlation IDs for request tracking.
-- Explain how to monitor API performance, errors, and usage patterns.
-
-## Testing
-
-- Always include test cases for critical paths of the application.
-- Guide users through creating unit tests.
-- Do not emit "Act", "Arrange" or "Assert" comments.
-- Copy existing style in nearby files for test method names and capitalization.
-- Explain integration testing approaches for API endpoints.
-- Demonstrate how to mock dependencies for effective testing.
-- Show how to test authentication and authorization logic.
-- Explain test-driven development principles as applied to API development.
-
-## Performance Optimization
-
-- Guide users on implementing caching strategies (in-memory, distributed, response caching).
-- Explain asynchronous programming patterns and why they matter for API performance.
-- Demonstrate pagination, filtering, and sorting for large data sets.
-- Show how to implement compression and other performance optimizations.
-- Explain how to measure and benchmark API performance.
-
-## Deployment and DevOps
-
-- Guide users through containerizing their API using .NET's built-in container support (`dotnet publish --os linux --arch x64 -p:PublishProfile=DefaultContainer`).
-- Explain the differences between manual Dockerfile creation and .NET's container publishing features.
-- Explain CI/CD pipelines for NET applications.
-- Demonstrate deployment to Azure App Service, Azure Container Apps, or other hosting options.
-- Show how to implement health checks and readiness probes.
-- Explain environment-specific configurations for different deployment stages.

.github/prompts/create-readme.prompt.md

@@ -1,21 +0,0 @@
----
-mode: 'agent'
-description: 'Create a README.md file for the project'
----
-
-## Role
-
-You're a senior expert software engineer with extensive experience in open source projects. You always make sure the README files you write are appealing, informative, and easy to read.
-
-## Task
-
-1. Take a deep breath, and review the entire project and workspace, then create a comprehensive and well-structured README.md file for the project.
-2. Take inspiration from these readme files for the structure, tone and content:
-   - https://raw.githubusercontent.com/Azure-Samples/serverless-chat-langchainjs/refs/heads/main/README.md
-   - https://raw.githubusercontent.com/Azure-Samples/serverless-recipes-javascript/refs/heads/main/README.md
-   - https://raw.githubusercontent.com/sinedied/run-on-output/refs/heads/main/README.md
-   - https://raw.githubusercontent.com/sinedied/smoke/refs/heads/main/README.md
-3. Do not overuse emojis, and keep the readme concise and to the point.
-4. Do not include sections like "LICENSE", "CONTRIBUTING", "CHANGELOG", etc. There are dedicated files for those sections.
-5. Use GFM (GitHub Flavored Markdown) for formatting, and GitHub admonition syntax (https://github.com/orgs/community/discussions/16925) where appropriate.
-6. If you find a logo or icon for the project, use it in the readme's header.

.github/prompts/create-specification.prompt.md

@@ -1,127 +0,0 @@
----
-mode: 'agent'
-description: 'Create a new specification file for the solution, optimized for Generative AI consumption.'
-tools: ['changes', 'search/codebase', 'edit/editFiles', 'extensions', 'fetch', 'githubRepo', 'openSimpleBrowser', 'problems', 'runTasks', 'search', 'search/searchResults', 'runCommands/terminalLastCommand', 'runCommands/terminalSelection', 'testFailure', 'usages', 'vscodeAPI']
----
-# Create Specification
-
-Your goal is to create a new specification file for `${input:SpecPurpose}`.
-
-The specification file must define the requirements, constraints, and interfaces for the solution components in a manner that is clear, unambiguous, and structured for effective use by Generative AIs. Follow established documentation standards and ensure the content is machine-readable and self-contained.
-
-## Best Practices for AI-Ready Specifications
-
-- Use precise, explicit, and unambiguous language.
-- Clearly distinguish between requirements, constraints, and recommendations.
-- Use structured formatting (headings, lists, tables) for easy parsing.
-- Avoid idioms, metaphors, or context-dependent references.
-- Define all acronyms and domain-specific terms.
-- Include examples and edge cases where applicable.
-- Ensure the document is self-contained and does not rely on external context.
-
-The specification should be saved in the [/spec/](/spec/) directory and named according to the following convention: `spec-[a-z0-9-]+.md`, where the name should be descriptive of the specification's content and starting with the highlevel purpose, which is one of [schema, tool, data, infrastructure, process, architecture, or design].
-
-The specification file must be formatted in well formed Markdown.
-
-Specification files must follow the template below, ensuring that all sections are filled out appropriately. The front matter for the markdown should be structured correctly as per the example following:
-
-```md
----
-title: [Concise Title Describing the Specification's Focus]
-version: [Optional: e.g., 1.0, Date]
-date_created: [YYYY-MM-DD]
-last_updated: [Optional: YYYY-MM-DD]
-owner: [Optional: Team/Individual responsible for this spec]
-tags: [Optional: List of relevant tags or categories, e.g., `infrastructure`, `process`, `design`, `app` etc]
----
-
-# Introduction
-
-[A short concise introduction to the specification and the goal it is intended to achieve.]
-
-## 1. Purpose & Scope
-
-[Provide a clear, concise description of the specification's purpose and the scope of its application. State the intended audience and any assumptions.]
-
-## 2. Definitions
-
-[List and define all acronyms, abbreviations, and domain-specific terms used in this specification.]
-
-## 3. Requirements, Constraints & Guidelines
-
-[Explicitly list all requirements, constraints, rules, and guidelines. Use bullet points or tables for clarity.]
-
-- **REQ-001**: Requirement 1
-- **SEC-001**: Security Requirement 1
-- **[3 LETTERS]-001**: Other Requirement 1
-- **CON-001**: Constraint 1
-- **GUD-001**: Guideline 1
-- **PAT-001**: Pattern to follow 1
-
-## 4. Interfaces & Data Contracts
-
-[Describe the interfaces, APIs, data contracts, or integration points. Use tables or code blocks for schemas and examples.]
-
-## 5. Acceptance Criteria
-
-[Define clear, testable acceptance criteria for each requirement using Given-When-Then format where appropriate.]
-
-- **AC-001**: Given [context], When [action], Then [expected outcome]
-- **AC-002**: The system shall [specific behavior] when [condition]
-- **AC-003**: [Additional acceptance criteria as needed]
-
-## 6. Test Automation Strategy
-
-[Define the testing approach, frameworks, and automation requirements.]
-
-- **Test Levels**: Unit, Integration, End-to-End
-- **Frameworks**: MSTest, FluentAssertions, Moq (for .NET applications)
-- **Test Data Management**: [approach for test data creation and cleanup]
-- **CI/CD Integration**: [automated testing in GitHub Actions pipelines]
-- **Coverage Requirements**: [minimum code coverage thresholds]
-- **Performance Testing**: [approach for load and performance testing]
-
-## 7. Rationale & Context
-
-[Explain the reasoning behind the requirements, constraints, and guidelines. Provide context for design decisions.]
-
-## 8. Dependencies & External Integrations
-
-[Define the external systems, services, and architectural dependencies required for this specification. Focus on **what** is needed rather than **how** it's implemented. Avoid specific package or library versions unless they represent architectural constraints.]
-
-### External Systems
-- **EXT-001**: [External system name] - [Purpose and integration type]
-
-### Third-Party Services
-- **SVC-001**: [Service name] - [Required capabilities and SLA requirements]
-
-### Infrastructure Dependencies
-- **INF-001**: [Infrastructure component] - [Requirements and constraints]
-
-### Data Dependencies
-- **DAT-001**: [External data source] - [Format, frequency, and access requirements]
-
-### Technology Platform Dependencies
-- **PLT-001**: [Platform/runtime requirement] - [Version constraints and rationale]
-
-### Compliance Dependencies
-- **COM-001**: [Regulatory or compliance requirement] - [Impact on implementation]
-
-**Note**: This section should focus on architectural and business dependencies, not specific package implementations. For example, specify "OAuth 2.0 authentication library" rather than "Microsoft.AspNetCore.Authentication.JwtBearer v6.0.1".
-
-## 9. Examples & Edge Cases
-
-    ```code
-    // Code snippet or data example demonstrating the correct application of the guidelines, including edge cases
-    ```
-
-## 10. Validation Criteria
-
-[List the criteria or tests that must be satisfied for compliance with this specification.]
-
-## 11. Related Specifications / Further Reading
-
-[Link to related spec 1]
-[Link to relevant external documentation]
-
-```

.github/prompts/csharp-async.prompt.md

@@ -1,50 +0,0 @@
----
-mode: 'agent'
-tools: ['changes', 'search/codebase', 'edit/editFiles', 'problems']
-description: 'Get best practices for C# async programming'
----
-
-# C# Async Programming Best Practices
-
-Your goal is to help me follow best practices for asynchronous programming in C#.
-
-## Naming Conventions
-
-- Use the 'Async' suffix for all async methods
-- Match method names with their synchronous counterparts when applicable (e.g., `GetDataAsync()` for `GetData()`)
-
-## Return Types
-
-- Return `Task<T>` when the method returns a value
-- Return `Task` when the method doesn't return a value
-- Consider `ValueTask<T>` for high-performance scenarios to reduce allocations
-- Avoid returning `void` for async methods except for event handlers
-
-## Exception Handling
-
-- Use try/catch blocks around await expressions
-- Avoid swallowing exceptions in async methods
-- Use `ConfigureAwait(false)` when appropriate to prevent deadlocks in library code
-- Propagate exceptions with `Task.FromException()` instead of throwing in async Task returning methods
-
-## Performance
-
-- Use `Task.WhenAll()` for parallel execution of multiple tasks
-- Use `Task.WhenAny()` for implementing timeouts or taking the first completed task
-- Avoid unnecessary async/await when simply passing through task results
-- Consider cancellation tokens for long-running operations
-
-## Common Pitfalls
-
-- Never use `.Wait()`, `.Result`, or `.GetAwaiter().GetResult()` in async code
-- Avoid mixing blocking and async code
-- Don't create async void methods (except for event handlers)
-- Always await Task-returning methods
-
-## Implementation Patterns
-
-- Implement the async command pattern for long-running operations
-- Use async streams (IAsyncEnumerable<T>) for processing sequences asynchronously
-- Consider the task-based asynchronous pattern (TAP) for public APIs
-
-When reviewing my C# code, identify these issues and suggest improvements that follow these best practices.

.github/prompts/csharp-xunit.prompt.md

@@ -1,69 +0,0 @@
----
-mode: 'agent'
-tools: ['changes', 'search/codebase', 'edit/editFiles', 'problems', 'search']
-description: 'Get best practices for XUnit unit testing, including data-driven tests'
----
-
-# XUnit Best Practices
-
-Your goal is to help me write effective unit tests with XUnit, covering both standard and data-driven testing approaches.
-
-## Project Setup
-
-- Use a separate test project with naming convention `[ProjectName].Tests`
-- Reference Microsoft.NET.Test.Sdk, xunit, and xunit.runner.visualstudio packages
-- Create test classes that match the classes being tested (e.g., `CalculatorTests` for `Calculator`)
-- Use .NET SDK test commands: `dotnet test` for running tests
-
-## Test Structure
-
-- No test class attributes required (unlike MSTest/NUnit)
-- Use fact-based tests with `[Fact]` attribute for simple tests
-- Follow the Arrange-Act-Assert (AAA) pattern
-- Name tests using the pattern `MethodName_Scenario_ExpectedBehavior`
-- Use constructor for setup and `IDisposable.Dispose()` for teardown
-- Use `IClassFixture<T>` for shared context between tests in a class
-- Use `ICollectionFixture<T>` for shared context between multiple test classes
-
-## Standard Tests
-
-- Keep tests focused on a single behavior
-- Avoid testing multiple behaviors in one test method
-- Use clear assertions that express intent
-- Include only the assertions needed to verify the test case
-- Make tests independent and idempotent (can run in any order)
-- Avoid test interdependencies
-
-## Data-Driven Tests
-
-- Use `[Theory]` combined with data source attributes
-- Use `[InlineData]` for inline test data
-- Use `[MemberData]` for method-based test data
-- Use `[ClassData]` for class-based test data
-- Create custom data attributes by implementing `DataAttribute`
-- Use meaningful parameter names in data-driven tests
-
-## Assertions
-
-- Use `Assert.Equal` for value equality
-- Use `Assert.Same` for reference equality
-- Use `Assert.True`/`Assert.False` for boolean conditions
-- Use `Assert.Contains`/`Assert.DoesNotContain` for collections
-- Use `Assert.Matches`/`Assert.DoesNotMatch` for regex pattern matching
-- Use `Assert.Throws<T>` or `await Assert.ThrowsAsync<T>` to test exceptions
-- Use fluent assertions library for more readable assertions
-
-## Mocking and Isolation
-
-- Consider using Moq or NSubstitute alongside XUnit
-- Mock dependencies to isolate units under test
-- Use interfaces to facilitate mocking
-- Consider using a DI container for complex test setups
-
-## Test Organization
-
-- Group tests by feature or component
-- Use `[Trait("Category", "CategoryName")]` for categorization
-- Use collection fixtures to group tests with shared dependencies
-- Consider output helpers (`ITestOutputHelper`) for test diagnostics
-- Skip tests conditionally with `Skip = "reason"` in fact/theory attributes

.github/prompts/dotnet-best-practices.prompt.md

@@ -1,84 +0,0 @@
----
-mode: 'agent'
-description: 'Ensure .NET/C# code meets best practices for the solution/project.'
----
-# .NET/C# Best Practices
-
-Your task is to ensure .NET/C# code in ${selection} meets the best practices specific to this solution/project. This includes:
-
-## Documentation & Structure
-
-- Create comprehensive XML documentation comments for all public classes, interfaces, methods, and properties
-- Include parameter descriptions and return value descriptions in XML comments
-- Follow the established namespace structure: {Core|Console|App|Service}.{Feature}
-
-## Design Patterns & Architecture
-
-- Use primary constructor syntax for dependency injection (e.g., `public class MyClass(IDependency dependency)`)
-- Implement the Command Handler pattern with generic base classes (e.g., `CommandHandler<TOptions>`)
-- Use interface segregation with clear naming conventions (prefix interfaces with 'I')
-- Follow the Factory pattern for complex object creation.
-
-## Dependency Injection & Services
-
-- Use constructor dependency injection with null checks via ArgumentNullException
-- Register services with appropriate lifetimes (Singleton, Scoped, Transient)
-- Use Microsoft.Extensions.DependencyInjection patterns
-- Implement service interfaces for testability
-
-## Resource Management & Localization
-
-- Use ResourceManager for localized messages and error strings
-- Separate LogMessages and ErrorMessages resource files
-- Access resources via `_resourceManager.GetString("MessageKey")`
-
-## Async/Await Patterns
-
-- Use async/await for all I/O operations and long-running tasks
-- Return Task or Task<T> from async methods
-- Use ConfigureAwait(false) where appropriate
-- Handle async exceptions properly
-
-## Testing Standards
-
-- Use MSTest framework with FluentAssertions for assertions
-- Follow AAA pattern (Arrange, Act, Assert)
-- Use Moq for mocking dependencies
-- Test both success and failure scenarios
-- Include null parameter validation tests
-
-## Configuration & Settings
-
-- Use strongly-typed configuration classes with data annotations
-- Implement validation attributes (Required, NotEmptyOrWhitespace)
-- Use IConfiguration binding for settings
-- Support appsettings.json configuration files
-
-## Semantic Kernel & AI Integration
-
-- Use Microsoft.SemanticKernel for AI operations
-- Implement proper kernel configuration and service registration
-- Handle AI model settings (ChatCompletion, Embedding, etc.)
-- Use structured output patterns for reliable AI responses
-
-## Error Handling & Logging
-
-- Use structured logging with Microsoft.Extensions.Logging
-- Include scoped logging with meaningful context
-- Throw specific exceptions with descriptive messages
-- Use try-catch blocks for expected failure scenarios
-
-## Performance & Security
-
-- Use C# 12+ features and .NET 8 optimizations where applicable
-- Implement proper input validation and sanitization
-- Use parameterized queries for database operations
-- Follow secure coding practices for AI/ML operations
-
-## Code Quality
-
-- Ensure SOLID principles compliance
-- Avoid code duplication through base classes and utilities
-- Use meaningful names that reflect domain concepts
-- Keep methods focused and cohesive
-- Implement proper disposal patterns for resources

.github/prompts/dotnet-design-pattern-review.prompt.md

@@ -1,41 +0,0 @@
----
-mode: 'agent'
-description: 'Review the C#/.NET code for design pattern implementation and suggest improvements.'
----
-# .NET/C# Design Pattern Review
-
-Review the C#/.NET code in ${selection} for design pattern implementation and suggest improvements for the solution/project. Do not make any changes to the code, just provide a review.
-
-## Required Design Patterns
-
-- **Command Pattern**: Generic base classes (`CommandHandler<TOptions>`), `ICommandHandler<TOptions>` interface, `CommandHandlerOptions` inheritance, static `SetupCommand(IHost host)` methods
-- **Factory Pattern**: Complex object creation service provider integration
-- **Dependency Injection**: Primary constructor syntax, `ArgumentNullException` null checks, interface abstractions, proper service lifetimes
-- **Repository Pattern**: Async data access interfaces provider abstractions for connections
-- **Provider Pattern**: External service abstractions (database, AI), clear contracts, configuration handling
-- **Resource Pattern**: ResourceManager for localized messages, separate .resx files (LogMessages, ErrorMessages)
-
-## Review Checklist
-
-- **Design Patterns**: Identify patterns used. Are Command Handler, Factory, Provider, and Repository patterns correctly implemented? Missing beneficial patterns?
-- **Architecture**: Follow namespace conventions (`{Core|Console|App|Service}.{Feature}`)? Proper separation between Core/Console projects? Modular and readable?
-- **.NET Best Practices**: Primary constructors, async/await with Task returns, ResourceManager usage, structured logging, strongly-typed configuration?
-- **GoF Patterns**: Command, Factory, Template Method, Strategy patterns correctly implemented?
-- **SOLID Principles**: Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion violations?
-- **Performance**: Proper async/await, resource disposal, ConfigureAwait(false), parallel processing opportunities?
-- **Maintainability**: Clear separation of concerns, consistent error handling, proper configuration usage?
-- **Testability**: Dependencies abstracted via interfaces, mockable components, async testability, AAA pattern compatibility?
-- **Security**: Input validation, secure credential handling, parameterized queries, safe exception handling?
-- **Documentation**: XML docs for public APIs, parameter/return descriptions, resource file organization?
-- **Code Clarity**: Meaningful names reflecting domain concepts, clear intent through patterns, self-explanatory structure?
-- **Clean Code**: Consistent style, appropriate method/class size, minimal complexity, eliminated duplication?
-
-## Improvement Focus Areas
-
-- **Command Handlers**: Validation in base class, consistent error handling, proper resource management
-- **Factories**: Dependency configuration, service provider integration, disposal patterns
-- **Providers**: Connection management, async patterns, exception handling and logging
-- **Configuration**: Data annotations, validation attributes, secure sensitive value handling
-- **AI/ML Integration**: Semantic Kernel patterns, structured output handling, model configuration
-
-Provide specific, actionable recommendations for improvements aligned with the project's architecture and .NET best practices.

.github/workflows/dotnetcore.yml

@@ -14,7 +14,7 @@ jobs:
         os: [windows-latest, ubuntu-latest]
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: actions/setup-dotnet@v5
       with:
         dotnet-version: 8.0.x

Directory.Packages.props

@@ -1,7 +1,7 @@
 <Project>
   <ItemGroup>
     <PackageVersion Include="Bullseye" Version="6.0.0" />
-    <PackageVersion Include="AwesomeAssertions" Version="9.2.1" />
+    <PackageVersion Include="AwesomeAssertions" Version="9.3.0" />
     <PackageVersion Include="Glob" Version="1.1.9" />
     <PackageVersion Include="JetBrains.Profiler.SelfApi" Version="2.5.14" />
     <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="8.0.0" />

src/SharpCompress/Archives/AbstractArchive.cs

@@ -172,4 +172,9 @@ public abstract class AbstractArchive<TEntry, TVolume> : IArchive, IArchiveExtra
             return Entries.All(x => x.IsComplete);
         }
     }
+
+    public virtual bool IsMultiVolume =>
+        _sourceStream?.Files.Count > 1 || _sourceStream?.Streams.Count > 1;
+
+    public virtual bool SupportsMultiThreading => false;
 }

src/SharpCompress/Archives/IArchive.cs

@@ -45,4 +45,14 @@ public interface IArchive : IDisposable
     /// The total size of the files as uncompressed in the archive.
     /// </summary>
     long TotalUncompressSize { get; }
+
+    /// <summary>
+    /// Is the archive part of a multi-volume set.
+    /// </summary>
+    bool IsMultiVolume { get; }
+
+    /// <summary>
+    /// Does the archive support multi-threaded extraction.
+    /// </summary>
+    bool SupportsMultiThreading { get; }
 }

src/SharpCompress/Archives/IArchiveEntryExtensions.cs

@@ -88,7 +88,7 @@ public static class IArchiveEntryExtensions
             entry,
             destinationDirectory,
             options,
-            (x, opt) => entry.WriteToFileAsync(x, opt, cancellationToken),
+            entry.WriteToFileAsync,
             cancellationToken
         );
 
@@ -124,10 +124,11 @@ public static class IArchiveEntryExtensions
             entry,
             destinationFileName,
             options,
-            async (x, fm) =>
+            async (x, fm, ct) =>
             {
                 using var fs = File.Open(destinationFileName, fm);
-                await entry.WriteToAsync(fs, cancellationToken).ConfigureAwait(false);
-            }
+                await entry.WriteToAsync(fs, ct).ConfigureAwait(false);
+            },
+            cancellationToken
         );
 }

src/SharpCompress/Archives/Rar/FileInfoRarArchiveVolume.cs

@@ -1,39 +0,0 @@
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.IO;
-using System.Linq;
-using SharpCompress.Common.Rar;
-using SharpCompress.Common.Rar.Headers;
-using SharpCompress.IO;
-using SharpCompress.Readers;
-
-namespace SharpCompress.Archives.Rar;
-
-/// <summary>
-/// A rar part based on a FileInfo object
-/// </summary>
-internal class FileInfoRarArchiveVolume : RarVolume
-{
-    internal FileInfoRarArchiveVolume(FileInfo fileInfo, ReaderOptions options, int index)
-        : base(StreamingMode.Seekable, fileInfo.OpenRead(), FixOptions(options), index)
-    {
-        FileInfo = fileInfo;
-        FileParts = GetVolumeFileParts().ToArray().ToReadOnly();
-    }
-
-    private static ReaderOptions FixOptions(ReaderOptions options)
-    {
-        //make sure we're closing streams with fileinfo
-        options.LeaveStreamOpen = false;
-        return options;
-    }
-
-    internal ReadOnlyCollection<RarFilePart> FileParts { get; }
-
-    internal FileInfo FileInfo { get; }
-
-    internal override RarFilePart CreateFilePart(MarkHeader markHeader, FileHeader fileHeader) =>
-        new FileInfoRarFilePart(this, ReaderOptions.Password, markHeader, fileHeader, FileInfo);
-
-    internal override IEnumerable<RarFilePart> ReadFileParts() => FileParts;
-}

src/SharpCompress/Archives/Rar/FileInfoRarFilePart.cs

@@ -1,21 +0,0 @@
-using System.IO;
-using SharpCompress.Common.Rar.Headers;
-
-namespace SharpCompress.Archives.Rar;
-
-internal sealed class FileInfoRarFilePart : SeekableFilePart
-{
-    internal FileInfoRarFilePart(
-        FileInfoRarArchiveVolume volume,
-        string? password,
-        MarkHeader mh,
-        FileHeader fh,
-        FileInfo fi
-    )
-        : base(mh, fh, volume.Index, volume.Stream, password) => FileInfo = fi;
-
-    internal FileInfo FileInfo { get; }
-
-    internal override string FilePartName =>
-        "Rar File: " + FileInfo.FullName + " File Entry: " + FileHeader.FileName;
-}

src/SharpCompress/Archives/Rar/RarArchive.cs

@@ -47,9 +47,9 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     {
         sourceStream.LoadAllParts(); //request all streams
         var streams = sourceStream.Streams.ToArray();
-        var i = 0;
         if (streams.Length > 1 && IsRarFile(streams[1], ReaderOptions)) //test part 2 - true = multipart not split
         {
+            var i = 0;
             sourceStream.IsVolumes = true;
             streams[1].Position = 0;
             sourceStream.Position = 0;
@@ -57,12 +57,18 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
             return sourceStream.Streams.Select(a => new StreamRarArchiveVolume(
                 a,
                 ReaderOptions,
-                i++
+                i++,
+                IsMultiVolume
             ));
         }
 
         //split mode or single file
-        return new StreamRarArchiveVolume(sourceStream, ReaderOptions, i++).AsEnumerable();
+        return new StreamRarArchiveVolume(
+            sourceStream,
+            ReaderOptions,
+            0,
+            IsMultiVolume
+        ).AsEnumerable();
     }
 
     protected override IReader CreateReaderForSolidExtraction()
@@ -83,6 +89,7 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
     }
 
     public override bool IsSolid => Volumes.First().IsSolidArchive;
+    public override bool SupportsMultiThreading => !IsMultiVolume && !IsSolid;
 
     public virtual int MinVersion => Volumes.First().MinVersion;
     public virtual int MaxVersion => Volumes.First().MaxVersion;

src/SharpCompress/Archives/Rar/RarArchiveEntry.cs

@@ -134,4 +134,6 @@ public class RarArchiveEntry : RarEntry, IArchiveEntry
             );
         }
     }
+
+    public override bool SupportsMultiThreading => Parts.Single().SupportsMultiThreading;
 }

src/SharpCompress/Archives/Rar/SeekableRarFilePart.cs

@@ -1,25 +1,29 @@
 using System.IO;
 using SharpCompress.Common.Rar;
 using SharpCompress.Common.Rar.Headers;
+using SharpCompress.IO;
 
 namespace SharpCompress.Archives.Rar;
 
-internal class SeekableFilePart : RarFilePart
+internal class SeekableRarFilePart : RarFilePart
 {
     private readonly Stream _stream;
     private readonly string? _password;
+    private readonly bool _isMultiVolume;
 
-    internal SeekableFilePart(
+    internal SeekableRarFilePart(
         MarkHeader mh,
         FileHeader fh,
         int index,
         Stream stream,
-        string? password
+        string? password,
+        bool isMultiVolume
     )
         : base(mh, fh, index)
     {
         _stream = stream;
         _password = password;
+        _isMultiVolume = isMultiVolume;
     }
 
     internal override Stream GetCompressedStream()
@@ -42,4 +46,7 @@ internal class SeekableFilePart : RarFilePart
     }
 
     internal override string FilePartName => "Unknown Stream - File Entry: " + FileHeader.FileName;
+
+    public override bool SupportsMultiThreading =>
+        !_isMultiVolume && _stream is SourceStream ss && ss.IsFileMode && ss.Files.Count == 1;
 }

src/SharpCompress/Archives/Rar/StreamRarArchiveVolume.cs

@@ -9,11 +9,28 @@ namespace SharpCompress.Archives.Rar;
 
 internal class StreamRarArchiveVolume : RarVolume
 {
-    internal StreamRarArchiveVolume(Stream stream, ReaderOptions options, int index)
-        : base(StreamingMode.Seekable, stream, options, index) { }
+    private readonly bool _isMultiVolume;
+
+    internal StreamRarArchiveVolume(
+        Stream stream,
+        ReaderOptions options,
+        int index,
+        bool isMultiVolume
+    )
+        : base(StreamingMode.Seekable, stream, options, index)
+    {
+        _isMultiVolume = isMultiVolume;
+    }
 
     internal override IEnumerable<RarFilePart> ReadFileParts() => GetVolumeFileParts();
 
     internal override RarFilePart CreateFilePart(MarkHeader markHeader, FileHeader fileHeader) =>
-        new SeekableFilePart(markHeader, fileHeader, Index, Stream, ReaderOptions.Password);
+        new SeekableRarFilePart(
+            markHeader,
+            fileHeader,
+            Index,
+            Stream,
+            ReaderOptions.Password,
+            _isMultiVolume
+        );
 }

src/SharpCompress/Archives/Zip/ZipArchive.cs

@@ -283,7 +283,12 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
 
                             yield return new ZipArchiveEntry(
                                 this,
-                                new SeekableZipFilePart(headerFactory.NotNull(), deh, s)
+                                new SeekableZipFilePart(
+                                    headerFactory.NotNull(),
+                                    deh,
+                                    s,
+                                    IsMultiVolume
+                                )
                             );
                         }
                         break;
@@ -385,4 +390,6 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
         ((IStreamStack)stream).StackSeek(0);
         return ZipReader.Open(stream, ReaderOptions, Entries);
     }
+
+    public override bool SupportsMultiThreading => !IsMultiVolume;
 }

src/SharpCompress/Archives/Zip/ZipArchiveEntry.cs

@@ -23,5 +23,7 @@ public class ZipArchiveEntry : ZipEntry, IArchiveEntry
 
     public bool IsComplete => true;
 
+    public override bool SupportsMultiThreading => Parts.Single().SupportsMultiThreading;
+
     #endregion
 }

src/SharpCompress/Common/Arc/ArcEntryHeader.cs

@@ -57,7 +57,7 @@ namespace SharpCompress.Common.Arc
             return value switch
             {
                 1 or 2 => CompressionType.None,
-                3 => CompressionType.RLE90,
+                3 => CompressionType.Packed,
                 4 => CompressionType.Squeezed,
                 5 or 6 or 7 or 8 => CompressionType.Crunched,
                 9 => CompressionType.Squashed,

src/SharpCompress/Common/Arc/ArcFilePart.cs

@@ -44,7 +44,7 @@ namespace SharpCompress.Common.Arc
                             Header.CompressedSize
                         );
                         break;
-                    case CompressionType.RLE90:
+                    case CompressionType.Packed:
                         compressedStream = new RunLength90Stream(
                             _stream,
                             (int)Header.CompressedSize
@@ -54,6 +54,14 @@ namespace SharpCompress.Common.Arc
                         compressedStream = new SqueezeStream(_stream, (int)Header.CompressedSize);
                         break;
                     case CompressionType.Crunched:
+                        if (Header.OriginalSize > 128 * 1024)
+                        {
+                            throw new NotSupportedException(
+                                "CompressionMethod: "
+                                    + Header.CompressionMethod
+                                    + " with size > 128KB"
+                            );
+                        }
                         compressedStream = new ArcLzwStream(
                             _stream,
                             (int)Header.CompressedSize,

src/SharpCompress/Common/Arj/ArjFilePart.cs

@@ -41,7 +41,7 @@ namespace SharpCompress.Common.Arj
                     case CompressionMethod.CompressedMost:
                     case CompressionMethod.Compressed:
                     case CompressionMethod.CompressedFaster:
-                        if (Header.CompressedSize > 128 * 1024)
+                        if (Header.OriginalSize > 128 * 1024)
                         {
                             throw new NotSupportedException(
                                 "CompressionMethod: "

src/SharpCompress/Common/CompressionType.cs

@@ -23,7 +23,7 @@ public enum CompressionType
     Reduce4,
     Explode,
     Squeezed,
-    RLE90,
+    Packed,
     Crunched,
     Squashed,
     Crushed,

src/SharpCompress/Common/Entry.cs

@@ -87,4 +87,5 @@ public abstract class Entry : IEntry
     /// Entry file attribute.
     /// </summary>
     public virtual int? Attrib => throw new NotImplementedException();
+    public virtual bool SupportsMultiThreading => false;
 }

src/SharpCompress/Common/ExtractionMethods.cs

@@ -128,7 +128,7 @@ internal static class ExtractionMethods
         IEntry entry,
         string destinationDirectory,
         ExtractionOptions? options,
-        Func<string, ExtractionOptions?, Task> writeAsync,
+        Func<string, ExtractionOptions?, CancellationToken, Task> writeAsync,
         CancellationToken cancellationToken = default
     )
     {
@@ -189,7 +189,7 @@ internal static class ExtractionMethods
                     "Entry is trying to write a file outside of the destination directory."
                 );
             }
-            await writeAsync(destinationFileName, options).ConfigureAwait(false);
+            await writeAsync(destinationFileName, options, cancellationToken).ConfigureAwait(false);
         }
         else if (options.ExtractFullPath && !Directory.Exists(destinationFileName))
         {
@@ -201,7 +201,7 @@ internal static class ExtractionMethods
         IEntry entry,
         string destinationFileName,
         ExtractionOptions? options,
-        Func<string, FileMode, Task> openAndWriteAsync,
+        Func<string, FileMode, CancellationToken, Task> openAndWriteAsync,
         CancellationToken cancellationToken = default
     )
     {
@@ -225,7 +225,8 @@ internal static class ExtractionMethods
                 fm = FileMode.CreateNew;
             }
 
-            await openAndWriteAsync(destinationFileName, fm).ConfigureAwait(false);
+            await openAndWriteAsync(destinationFileName, fm, cancellationToken)
+                .ConfigureAwait(false);
             entry.PreserveExtractionOptions(destinationFileName, options);
         }
     }

src/SharpCompress/Common/FilePart.cs

@@ -14,4 +14,6 @@ public abstract class FilePart
     internal abstract Stream? GetCompressedStream();
     internal abstract Stream? GetRawStream();
     internal bool Skipped { get; set; }
+
+    public virtual bool SupportsMultiThreading => false;
 }

src/SharpCompress/Common/IEntry.cs

@@ -21,4 +21,5 @@ public interface IEntry
     DateTime? LastModifiedTime { get; }
     long Size { get; }
     int? Attrib { get; }
+    bool SupportsMultiThreading { get; }
 }

src/SharpCompress/Common/Zip/SeekableZipFilePart.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using SharpCompress.Common.Zip.Headers;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Zip;
 
@@ -7,13 +8,19 @@ internal class SeekableZipFilePart : ZipFilePart
 {
     private bool _isLocalHeaderLoaded;
     private readonly SeekableZipHeaderFactory _headerFactory;
+    private readonly bool _isMultiVolume;
 
     internal SeekableZipFilePart(
         SeekableZipHeaderFactory headerFactory,
         DirectoryEntryHeader header,
-        Stream stream
+        Stream stream,
+        bool isMultiVolume
     )
-        : base(header, stream) => _headerFactory = headerFactory;
+        : base(header, stream)
+    {
+        _headerFactory = headerFactory;
+        _isMultiVolume = isMultiVolume;
+    }
 
     internal override Stream GetCompressedStream()
     {
@@ -30,8 +37,20 @@ internal class SeekableZipFilePart : ZipFilePart
 
     protected override Stream CreateBaseStream()
     {
+        if (!_isMultiVolume && BaseStream is SourceStream ss)
+        {
+            if (ss.IsFileMode && ss.Files.Count == 1)
+            {
+                var fileStream = ss.CurrentFile.OpenRead();
+                fileStream.Position = Header.DataStartPosition.NotNull();
+                return fileStream;
+            }
+        }
         BaseStream.Position = Header.DataStartPosition.NotNull();
 
         return BaseStream;
     }
+
+    public override bool SupportsMultiThreading =>
+        !_isMultiVolume && BaseStream is SourceStream ss && ss.IsFileMode && ss.Files.Count == 1;
 }

src/SharpCompress/Compressors/Rar/MultiVolumeReadOnlyStream.cs

@@ -62,10 +62,6 @@ internal sealed class MultiVolumeReadOnlyStream : Stream, IStreamStack
         base.Dispose(disposing);
         if (disposing)
         {
-#if DEBUG_STREAMS
-            this.DebugDispose(typeof(MultiVolumeReadOnlyStream));
-#endif
-
             if (filePartEnumerator != null)
             {
                 filePartEnumerator.Dispose();

src/SharpCompress/Compressors/Rar/RarStream.cs

@@ -82,9 +82,6 @@ internal class RarStream : Stream, IStreamStack
         {
             if (disposing)
             {
-#if DEBUG_STREAMS
-                this.DebugDispose(typeof(RarStream));
-#endif
                 ArrayPool<byte>.Shared.Return(this.tmpBuffer);
                 this.tmpBuffer = null;
             }

src/SharpCompress/IO/SourceStream.cs

@@ -15,7 +15,7 @@ public class SourceStream : Stream, IStreamStack
 #endif
     int IStreamStack.DefaultBufferSize { get; set; }
 
-    Stream IStreamStack.BaseStream() => _streams[_stream];
+    Stream IStreamStack.BaseStream() => _streams[_streamIndex];
 
     int IStreamStack.BufferSize
     {
@@ -35,7 +35,7 @@ public class SourceStream : Stream, IStreamStack
     private readonly List<Stream> _streams;
     private readonly Func<int, FileInfo?>? _getFilePart;
     private readonly Func<int, Stream?>? _getStreamPart;
-    private int _stream;
+    private int _streamIndex;
 
     public SourceStream(FileInfo file, Func<int, FileInfo?> getPart, ReaderOptions options)
         : this(null, null, file, getPart, options) { }
@@ -59,7 +59,7 @@ public class SourceStream : Stream, IStreamStack
 
         if (!IsFileMode)
         {
-            _streams.Add(stream!);
+            _streams.Add(stream.NotNull("stream is null"));
             _getStreamPart = getStreamPart;
             _getFilePart = _ => null;
             if (stream is FileStream fileStream)
@@ -69,12 +69,12 @@ public class SourceStream : Stream, IStreamStack
         }
         else
         {
-            _files.Add(file!);
+            _files.Add(file.NotNull("file is null"));
             _streams.Add(_files[0].OpenRead());
             _getFilePart = getFilePart;
             _getStreamPart = _ => null;
         }
-        _stream = 0;
+        _streamIndex = 0;
         _prevSize = 0;
 
 #if DEBUG_STREAMS
@@ -93,10 +93,12 @@ public class SourceStream : Stream, IStreamStack
     public ReaderOptions ReaderOptions { get; }
     public bool IsFileMode { get; }
 
-    public IEnumerable<FileInfo> Files => _files;
-    public IEnumerable<Stream> Streams => _streams;
+    public IReadOnlyList<FileInfo> Files => _files;
+    public IReadOnlyList<Stream> Streams => _streams;
 
-    private Stream Current => _streams[_stream];
+    private Stream Current => _streams[_streamIndex];
+
+    public FileInfo CurrentFile => _files[_streamIndex];
 
     public bool LoadStream(int index) //ensure all parts to id are loaded
     {
@@ -107,7 +109,7 @@ public class SourceStream : Stream, IStreamStack
                 var f = _getFilePart.NotNull("GetFilePart is null")(_streams.Count);
                 if (f == null)
                 {
-                    _stream = _streams.Count - 1;
+                    _streamIndex = _streams.Count - 1;
                     return false;
                 }
                 //throw new Exception($"File part {idx} not available.");
@@ -119,7 +121,7 @@ public class SourceStream : Stream, IStreamStack
                 var s = _getStreamPart.NotNull("GetStreamPart is null")(_streams.Count);
                 if (s == null)
                 {
-                    _stream = _streams.Count - 1;
+                    _streamIndex = _streams.Count - 1;
                     return false;
                 }
                 //throw new Exception($"Stream part {idx} not available.");
@@ -137,10 +139,10 @@ public class SourceStream : Stream, IStreamStack
     {
         if (LoadStream(idx))
         {
-            _stream = idx;
+            _streamIndex = idx;
         }
 
-        return _stream == idx;
+        return _streamIndex == idx;
     }
 
     public override bool CanRead => true;
@@ -184,7 +186,7 @@ public class SourceStream : Stream, IStreamStack
                 var length = Current.Length;
 
                 // Load next file if present
-                if (!SetStream(_stream + 1))
+                if (!SetStream(_streamIndex + 1))
                 {
                     break;
                 }
@@ -223,7 +225,7 @@ public class SourceStream : Stream, IStreamStack
             while (_prevSize + Current.Length < pos)
             {
                 _prevSize += Current.Length;
-                SetStream(_stream + 1);
+                SetStream(_streamIndex + 1);
             }
         }
 
@@ -273,7 +275,7 @@ public class SourceStream : Stream, IStreamStack
                 var length = Current.Length;
 
                 // Load next file if present
-                if (!SetStream(_stream + 1))
+                if (!SetStream(_streamIndex + 1))
                 {
                     break;
                 }
@@ -322,7 +324,7 @@ public class SourceStream : Stream, IStreamStack
                 var length = Current.Length;
 
                 // Load next file if present
-                if (!SetStream(_stream + 1))
+                if (!SetStream(_streamIndex + 1))
                 {
                     break;
                 }

src/SharpCompress/Readers/IReaderExtensions.cs

@@ -82,7 +82,7 @@ public static class IReaderExtensions
                 reader.Entry,
                 destinationDirectory,
                 options,
-                (fileName, opts) => reader.WriteEntryToFileAsync(fileName, opts, cancellationToken),
+                reader.WriteEntryToFileAsync,
                 cancellationToken
             )
             .ConfigureAwait(false);
@@ -101,10 +101,10 @@ public static class IReaderExtensions
                 reader.Entry,
                 destinationFileName,
                 options,
-                async (x, fm) =>
+                async (x, fm, ct) =>
                 {
                     using var fs = File.Open(destinationFileName, fm);
-                    await reader.WriteEntryToAsync(fs, cancellationToken).ConfigureAwait(false);
+                    await reader.WriteEntryToAsync(fs, ct).ConfigureAwait(false);
                 },
                 cancellationToken
             )

src/SharpCompress/Writers/Zip/ZipCentralDirectoryEntry.cs

@@ -48,7 +48,29 @@ internal class ZipCentralDirectoryEntry
         var decompressedvalue = zip64 ? uint.MaxValue : (uint)Decompressed;
         var headeroffsetvalue = zip64 ? uint.MaxValue : (uint)HeaderOffset;
         var extralength = zip64 ? (2 + 2 + 8 + 8 + 8 + 4) : 0;
-        var version = (byte)(zip64 ? 45 : 20); // Version 20 required for deflate/encryption
+
+        // Determine version needed to extract:
+        // - Version 63 for LZMA, PPMd, BZip2, ZStandard (advanced compression methods)
+        // - Version 45 for Zip64 extensions (when Zip64HeaderOffset != 0 or actual sizes require it)
+        // - Version 20 for standard Deflate/None compression
+        byte version;
+        if (
+            compression == ZipCompressionMethod.LZMA
+            || compression == ZipCompressionMethod.PPMd
+            || compression == ZipCompressionMethod.BZip2
+            || compression == ZipCompressionMethod.ZStandard
+        )
+        {
+            version = 63;
+        }
+        else if (zip64 || Zip64HeaderOffset != 0)
+        {
+            version = 45;
+        }
+        else
+        {
+            version = 20;
+        }
 
         var flags = Equals(archiveEncoding.GetEncoding(), Encoding.UTF8)
             ? HeaderFlags.Efs

tests/SharpCompress.Test/Arc/ArcReaderTests.cs

@@ -27,5 +27,22 @@ namespace SharpCompress.Test.Arc
 
         [Fact]
         public void Arc_Crunched_Read() => Read("Arc.crunched.arc");
+
+        [Theory]
+        [InlineData("Arc.crunched.largefile.arc", CompressionType.Crunched)]
+        public void Arc_LargeFile_ShouldThrow(string fileName, CompressionType compressionType)
+        {
+            var exception = Assert.Throws<NotSupportedException>(() =>
+                ReadForBufferBoundaryCheck(fileName, compressionType)
+            );
+        }
+
+        [Theory]
+        [InlineData("Arc.uncompressed.largefile.arc", CompressionType.None)]
+        [InlineData("Arc.squeezed.largefile.arc", CompressionType.Squeezed)]
+        public void Arc_LargeFileTest_Read(string fileName, CompressionType compressionType)
+        {
+            ReadForBufferBoundaryCheck(fileName, compressionType);
+        }
     }
 }

tests/SharpCompress.Test/ArchiveTests.cs

@@ -134,6 +134,7 @@ public class ArchiveTests : ReaderTests
                 {
                     foreach (var entry in archive.Entries.Where(entry => !entry.IsDirectory))
                     {
+                        Assert.False(entry.SupportsMultiThreading);
                         entry.WriteToDirectory(
                             SCRATCH_FILES_PATH,
                             new ExtractionOptions { ExtractFullPath = true, Overwrite = true }
@@ -266,6 +267,31 @@ public class ArchiveTests : ReaderTests
         VerifyFiles();
     }
 
+    protected async Task ArchiveFileRead_Multithreaded(
+        IArchiveFactory archiveFactory,
+        string testArchive,
+        ReaderOptions? readerOptions = null
+    )
+    {
+        testArchive = Path.Combine(TEST_ARCHIVES_PATH, testArchive);
+        var tasks = new List<Task>();
+        using (var archive = archiveFactory.Open(new FileInfo(testArchive), readerOptions))
+        {
+            Assert.True(archive.SupportsMultiThreading);
+            foreach (var entry in archive.Entries.Where(entry => !entry.IsDirectory))
+            {
+                Assert.True(entry.SupportsMultiThreading);
+                var t = entry.WriteToDirectoryAsync(
+                    SCRATCH_FILES_PATH,
+                    new ExtractionOptions { ExtractFullPath = true, Overwrite = true }
+                );
+                tasks.Add(t);
+            }
+        }
+        await Task.WhenAll(tasks);
+        VerifyFiles();
+    }
+
     protected void ArchiveFileRead(
         IArchiveFactory archiveFactory,
         string testArchive,
@@ -289,6 +315,11 @@ public class ArchiveTests : ReaderTests
     protected void ArchiveFileRead(string testArchive, ReaderOptions? readerOptions = null) =>
         ArchiveFileRead(ArchiveFactory.AutoFactory, testArchive, readerOptions);
 
+    protected Task ArchiveFileRead_Multithreaded(
+        string testArchive,
+        ReaderOptions? readerOptions = null
+    ) => ArchiveFileRead_Multithreaded(ArchiveFactory.AutoFactory, testArchive, readerOptions);
+
     protected void ArchiveFileSkip(
         string testArchive,
         string fileOrder,

tests/SharpCompress.Test/Arj/ArjReaderTests.cs

@@ -45,16 +45,14 @@ namespace SharpCompress.Test.Arj
         public void Arj_Multi_Reader()
         {
             var exception = Assert.Throws<MultiVolumeExtractionException>(() =>
-                DoArj_Multi_Reader(
-                    [
-                        "Arj.store.split.arj",
-                        "Arj.store.split.a01",
-                        "Arj.store.split.a02",
-                        "Arj.store.split.a03",
-                        "Arj.store.split.a04",
-                        "Arj.store.split.a05",
-                    ]
-                )
+                DoArj_Multi_Reader([
+                    "Arj.store.split.arj",
+                    "Arj.store.split.a01",
+                    "Arj.store.split.a02",
+                    "Arj.store.split.a03",
+                    "Arj.store.split.a04",
+                    "Arj.store.split.a05",
+                ])
             );
         }
 
@@ -65,7 +63,7 @@ namespace SharpCompress.Test.Arj
         public void Arj_LargeFile_ShouldThrow(string fileName, CompressionType compressionType)
         {
             var exception = Assert.Throws<NotSupportedException>(() =>
-                Arj_LargeFileTest_Read(fileName, compressionType)
+                ReadForBufferBoundaryCheck(fileName, compressionType)
             );
         }
 
@@ -74,24 +72,7 @@ namespace SharpCompress.Test.Arj
         [InlineData("Arj.method4.largefile.arj", CompressionType.ArjLZ77)]
         public void Arj_LargeFileTest_Read(string fileName, CompressionType compressionType)
         {
-            using (var stream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, fileName)))
-            using (
-                var reader = ReaderFactory.Open(stream, new ReaderOptions { LookForHeader = true })
-            )
-            {
-                while (reader.MoveToNextEntry())
-                {
-                    Assert.Equal(compressionType, reader.Entry.CompressionType);
-                    reader.WriteEntryToDirectory(
-                        SCRATCH_FILES_PATH,
-                        new ExtractionOptions { ExtractFullPath = true, Overwrite = true }
-                    );
-                }
-            }
-            CompareFilesByPath(
-                Path.Combine(SCRATCH_FILES_PATH, "news.txt"),
-                Path.Combine(MISC_TEST_FILES_PATH, "news.txt")
-            );
+            ReadForBufferBoundaryCheck(fileName, compressionType);
         }
 
         private void DoArj_Multi_Reader(string[] archives)

tests/SharpCompress.Test/Rar/RarArchiveTests.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using System.Linq;
+using System.Threading.Tasks;
 using SharpCompress.Archives;
 using SharpCompress.Archives.Rar;
 using SharpCompress.Common;
@@ -292,9 +293,15 @@ public class RarArchiveTests : ArchiveTests
     [Fact]
     public void Rar_ArchiveFileRead() => ArchiveFileRead("Rar.rar");
 
+    [Fact]
+    public Task Rar_ArchiveFileRead_Multithreaded() => ArchiveFileRead_Multithreaded("Rar.rar");
+
     [Fact]
     public void Rar5_ArchiveFileRead() => ArchiveFileRead("Rar5.rar");
 
+    [Fact]
+    public Task Rar5_ArchiveFileRead_Multithreaded() => ArchiveFileRead_Multithreaded("Rar5.rar");
+
     [Fact]
     public void Rar_ArchiveFileRead_HasDirectories() =>
         DoRar_ArchiveFileRead_HasDirectories("Rar.rar");
@@ -359,6 +366,9 @@ public class RarArchiveTests : ArchiveTests
     [Fact]
     public void Rar2_ArchiveFileRead() => ArchiveFileRead("Rar2.rar");
 
+    [Fact]
+    public Task Rar2_ArchiveFileRead_Multithreaded() => ArchiveFileRead_Multithreaded("Rar2.rar");
+
     [Fact]
     public void Rar15_ArchiveFileRead()
     {

tests/SharpCompress.Test/Rar/RarReaderAsyncTests.cs

@@ -15,29 +15,25 @@ public class RarReaderAsyncTests : ReaderTests
 {
     [Fact]
     public async Task Rar_Multi_Reader_Async() =>
-        await DoRar_Multi_Reader_Async(
-            [
-                "Rar.multi.part01.rar",
-                "Rar.multi.part02.rar",
-                "Rar.multi.part03.rar",
-                "Rar.multi.part04.rar",
-                "Rar.multi.part05.rar",
-                "Rar.multi.part06.rar",
-            ]
-        );
+        await DoRar_Multi_Reader_Async([
+            "Rar.multi.part01.rar",
+            "Rar.multi.part02.rar",
+            "Rar.multi.part03.rar",
+            "Rar.multi.part04.rar",
+            "Rar.multi.part05.rar",
+            "Rar.multi.part06.rar",
+        ]);
 
     [Fact]
     public async Task Rar5_Multi_Reader_Async() =>
-        await DoRar_Multi_Reader_Async(
-            [
-                "Rar5.multi.part01.rar",
-                "Rar5.multi.part02.rar",
-                "Rar5.multi.part03.rar",
-                "Rar5.multi.part04.rar",
-                "Rar5.multi.part05.rar",
-                "Rar5.multi.part06.rar",
-            ]
-        );
+        await DoRar_Multi_Reader_Async([
+            "Rar5.multi.part01.rar",
+            "Rar5.multi.part02.rar",
+            "Rar5.multi.part03.rar",
+            "Rar5.multi.part04.rar",
+            "Rar5.multi.part05.rar",
+            "Rar5.multi.part06.rar",
+        ]);
 
     private async Task DoRar_Multi_Reader_Async(string[] archives)
     {
@@ -95,29 +91,25 @@ public class RarReaderAsyncTests : ReaderTests
 
     [Fact]
     public async Task Rar_Multi_Reader_Delete_Files_Async() =>
-        await DoRar_Multi_Reader_Delete_Files_Async(
-            [
-                "Rar.multi.part01.rar",
-                "Rar.multi.part02.rar",
-                "Rar.multi.part03.rar",
-                "Rar.multi.part04.rar",
-                "Rar.multi.part05.rar",
-                "Rar.multi.part06.rar",
-            ]
-        );
+        await DoRar_Multi_Reader_Delete_Files_Async([
+            "Rar.multi.part01.rar",
+            "Rar.multi.part02.rar",
+            "Rar.multi.part03.rar",
+            "Rar.multi.part04.rar",
+            "Rar.multi.part05.rar",
+            "Rar.multi.part06.rar",
+        ]);
 
     [Fact]
     public async Task Rar5_Multi_Reader_Delete_Files_Async() =>
-        await DoRar_Multi_Reader_Delete_Files_Async(
-            [
-                "Rar5.multi.part01.rar",
-                "Rar5.multi.part02.rar",
-                "Rar5.multi.part03.rar",
-                "Rar5.multi.part04.rar",
-                "Rar5.multi.part05.rar",
-                "Rar5.multi.part06.rar",
-            ]
-        );
+        await DoRar_Multi_Reader_Delete_Files_Async([
+            "Rar5.multi.part01.rar",
+            "Rar5.multi.part02.rar",
+            "Rar5.multi.part03.rar",
+            "Rar5.multi.part04.rar",
+            "Rar5.multi.part05.rar",
+            "Rar5.multi.part06.rar",
+        ]);
 
     private async Task DoRar_Multi_Reader_Delete_Files_Async(string[] archives)
     {

tests/SharpCompress.Test/Rar/RarReaderTests.cs

@@ -14,29 +14,25 @@ public class RarReaderTests : ReaderTests
 {
     [Fact]
     public void Rar_Multi_Reader() =>
-        DoRar_Multi_Reader(
-            [
-                "Rar.multi.part01.rar",
-                "Rar.multi.part02.rar",
-                "Rar.multi.part03.rar",
-                "Rar.multi.part04.rar",
-                "Rar.multi.part05.rar",
-                "Rar.multi.part06.rar",
-            ]
-        );
+        DoRar_Multi_Reader([
+            "Rar.multi.part01.rar",
+            "Rar.multi.part02.rar",
+            "Rar.multi.part03.rar",
+            "Rar.multi.part04.rar",
+            "Rar.multi.part05.rar",
+            "Rar.multi.part06.rar",
+        ]);
 
     [Fact]
     public void Rar5_Multi_Reader() =>
-        DoRar_Multi_Reader(
-            [
-                "Rar5.multi.part01.rar",
-                "Rar5.multi.part02.rar",
-                "Rar5.multi.part03.rar",
-                "Rar5.multi.part04.rar",
-                "Rar5.multi.part05.rar",
-                "Rar5.multi.part06.rar",
-            ]
-        );
+        DoRar_Multi_Reader([
+            "Rar5.multi.part01.rar",
+            "Rar5.multi.part02.rar",
+            "Rar5.multi.part03.rar",
+            "Rar5.multi.part04.rar",
+            "Rar5.multi.part05.rar",
+            "Rar5.multi.part06.rar",
+        ]);
 
     private void DoRar_Multi_Reader(string[] archives)
     {
@@ -61,16 +57,14 @@ public class RarReaderTests : ReaderTests
 
     [Fact]
     public void Rar_Multi_Reader_Encrypted() =>
-        DoRar_Multi_Reader_Encrypted(
-            [
-                "Rar.EncryptedParts.part01.rar",
-                "Rar.EncryptedParts.part02.rar",
-                "Rar.EncryptedParts.part03.rar",
-                "Rar.EncryptedParts.part04.rar",
-                "Rar.EncryptedParts.part05.rar",
-                "Rar.EncryptedParts.part06.rar",
-            ]
-        );
+        DoRar_Multi_Reader_Encrypted([
+            "Rar.EncryptedParts.part01.rar",
+            "Rar.EncryptedParts.part02.rar",
+            "Rar.EncryptedParts.part03.rar",
+            "Rar.EncryptedParts.part04.rar",
+            "Rar.EncryptedParts.part05.rar",
+            "Rar.EncryptedParts.part06.rar",
+        ]);
 
     private void DoRar_Multi_Reader_Encrypted(string[] archives) =>
         Assert.Throws<InvalidFormatException>(() =>
@@ -97,29 +91,25 @@ public class RarReaderTests : ReaderTests
 
     [Fact]
     public void Rar_Multi_Reader_Delete_Files() =>
-        DoRar_Multi_Reader_Delete_Files(
-            [
-                "Rar.multi.part01.rar",
-                "Rar.multi.part02.rar",
-                "Rar.multi.part03.rar",
-                "Rar.multi.part04.rar",
-                "Rar.multi.part05.rar",
-                "Rar.multi.part06.rar",
-            ]
-        );
+        DoRar_Multi_Reader_Delete_Files([
+            "Rar.multi.part01.rar",
+            "Rar.multi.part02.rar",
+            "Rar.multi.part03.rar",
+            "Rar.multi.part04.rar",
+            "Rar.multi.part05.rar",
+            "Rar.multi.part06.rar",
+        ]);
 
     [Fact]
     public void Rar5_Multi_Reader_Delete_Files() =>
-        DoRar_Multi_Reader_Delete_Files(
-            [
-                "Rar5.multi.part01.rar",
-                "Rar5.multi.part02.rar",
-                "Rar5.multi.part03.rar",
-                "Rar5.multi.part04.rar",
-                "Rar5.multi.part05.rar",
-                "Rar5.multi.part06.rar",
-            ]
-        );
+        DoRar_Multi_Reader_Delete_Files([
+            "Rar5.multi.part01.rar",
+            "Rar5.multi.part02.rar",
+            "Rar5.multi.part03.rar",
+            "Rar5.multi.part04.rar",
+            "Rar5.multi.part05.rar",
+            "Rar5.multi.part06.rar",
+        ]);
 
     private void DoRar_Multi_Reader_Delete_Files(string[] archives)
     {
@@ -407,16 +397,14 @@ public class RarReaderTests : ReaderTests
                 Path.Combine("exe", "test.exe"),
             }
         );
-        using var reader = RarReader.Open(
-            [
-                Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part01.rar"),
-                Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part02.rar"),
-                Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part03.rar"),
-                Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part04.rar"),
-                Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part05.rar"),
-                Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part06.rar"),
-            ]
-        );
+        using var reader = RarReader.Open([
+            Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part01.rar"),
+            Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part02.rar"),
+            Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part03.rar"),
+            Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part04.rar"),
+            Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part05.rar"),
+            Path.Combine(TEST_ARCHIVES_PATH, "Rar.multi.part06.rar"),
+        ]);
         while (reader.MoveToNextEntry())
         {
             Assert.Equal(expectedOrder.Pop(), reader.Entry.Key);

tests/SharpCompress.Test/ReaderTests.cs

@@ -176,6 +176,27 @@ public abstract class ReaderTests : TestBase
         }
     }
 
+    protected void ReadForBufferBoundaryCheck(string fileName, CompressionType compressionType)
+    {
+        using var stream = File.OpenRead(Path.Combine(TEST_ARCHIVES_PATH, fileName));
+        using var reader = ReaderFactory.Open(stream, new ReaderOptions { LookForHeader = true });
+
+        while (reader.MoveToNextEntry())
+        {
+            Assert.Equal(compressionType, reader.Entry.CompressionType);
+
+            reader.WriteEntryToDirectory(
+                SCRATCH_FILES_PATH,
+                new ExtractionOptions { ExtractFullPath = true, Overwrite = true }
+            );
+        }
+
+        CompareFilesByPath(
+            Path.Combine(SCRATCH_FILES_PATH, "alice29.txt"),
+            Path.Combine(MISC_TEST_FILES_PATH, "alice29.txt")
+        );
+    }
+
     protected void Iterate(
         string testArchive,
         string fileOrder,

tests/SharpCompress.Test/Xz/XZIndexAsyncTests.cs

@@ -74,9 +74,21 @@ public class XzIndexAsyncTests : XzTestsBase
     public async Task SkipsPaddingAsync()
     {
         // Index with 3-byte padding.
-        using Stream badStream = new MemoryStream(
-            [0x00, 0x01, 0x10, 0x80, 0x01, 0x00, 0x00, 0x00, 0xB1, 0x01, 0xD9, 0xC9, 0xFF]
-        );
+        using Stream badStream = new MemoryStream([
+            0x00,
+            0x01,
+            0x10,
+            0x80,
+            0x01,
+            0x00,
+            0x00,
+            0x00,
+            0xB1,
+            0x01,
+            0xD9,
+            0xC9,
+            0xFF,
+        ]);
         var br = new BinaryReader(badStream);
         var index = new XZIndex(br, false);
         await index.ProcessAsync().ConfigureAwait(false);

tests/SharpCompress.Test/Xz/XZIndexTests.cs

@@ -71,9 +71,21 @@ public class XzIndexTests : XzTestsBase
     public void SkipsPadding()
     {
         // Index with 3-byte padding.
-        using Stream badStream = new MemoryStream(
-            [0x00, 0x01, 0x10, 0x80, 0x01, 0x00, 0x00, 0x00, 0xB1, 0x01, 0xD9, 0xC9, 0xFF]
-        );
+        using Stream badStream = new MemoryStream([
+            0x00,
+            0x01,
+            0x10,
+            0x80,
+            0x01,
+            0x00,
+            0x00,
+            0x00,
+            0xB1,
+            0x01,
+            0xD9,
+            0xC9,
+            0xFF,
+        ]);
         var br = new BinaryReader(badStream);
         var index = new XZIndex(br, false);
         index.Process();

tests/SharpCompress.Test/Zip/Zip64VersionConsistencyTests.cs

@@ -0,0 +1,441 @@
+using System;
+using System.Buffers.Binary;
+using System.IO;
+using SharpCompress.Archives;
+using SharpCompress.Archives.Zip;
+using SharpCompress.Common;
+using SharpCompress.Writers;
+using SharpCompress.Writers.Zip;
+using Xunit;
+
+namespace SharpCompress.Test.Zip;
+
+/// <summary>
+/// Tests for verifying version consistency between Local File Header (LFH)
+/// and Central Directory File Header (CDFH) when using Zip64.
+/// </summary>
+public class Zip64VersionConsistencyTests : WriterTests
+{
+    public Zip64VersionConsistencyTests()
+        : base(ArchiveType.Zip) { }
+
+    [Fact]
+    public void Zip64_Small_File_With_UseZip64_Should_Have_Matching_Versions()
+    {
+        // Create a zip with UseZip64=true but with a small file
+        var filename = Path.Combine(SCRATCH2_FILES_PATH, "zip64_version_test.zip");
+
+        if (File.Exists(filename))
+        {
+            File.Delete(filename);
+        }
+
+        // Create archive with UseZip64=true
+        WriterOptions writerOptions = new ZipWriterOptions(CompressionType.Deflate)
+        {
+            LeaveStreamOpen = false,
+            UseZip64 = true,
+        };
+
+        ZipArchive zipArchive = ZipArchive.Create();
+        zipArchive.AddEntry("empty", new MemoryStream());
+        zipArchive.SaveTo(filename, writerOptions);
+
+        // Now read the raw bytes to verify version consistency
+        using var fs = File.OpenRead(filename);
+        using var br = new BinaryReader(fs);
+
+        // Read Local File Header
+        var lfhSignature = br.ReadUInt32();
+        Assert.Equal(0x04034b50u, lfhSignature); // Local file header signature
+
+        var lfhVersion = br.ReadUInt16();
+
+        // Skip to Central Directory
+        // Find Central Directory by searching from the end
+        fs.Seek(-22, SeekOrigin.End); // Min EOCD size
+        var eocdSignature = br.ReadUInt32();
+
+        if (eocdSignature != 0x06054b50u)
+        {
+            // Might have Zip64 EOCD, search backwards
+            fs.Seek(-100, SeekOrigin.End);
+            var buffer = new byte[100];
+            fs.Read(buffer, 0, 100);
+
+            // Find EOCD signature
+            for (int i = buffer.Length - 4; i >= 0; i--)
+            {
+                if (BinaryPrimitives.ReadUInt32LittleEndian(buffer.AsSpan(i)) == 0x06054b50u)
+                {
+                    fs.Seek(-100 + i, SeekOrigin.End);
+                    break;
+                }
+            }
+        }
+
+        // Read EOCD
+        fs.Seek(-22, SeekOrigin.End);
+        br.ReadUInt32(); // EOCD signature
+        br.ReadUInt16(); // disk number
+        br.ReadUInt16(); // disk with central dir
+        br.ReadUInt16(); // entries on this disk
+        br.ReadUInt16(); // total entries
+        br.ReadUInt32(); // central directory size (unused)
+        var cdOffset = br.ReadUInt32();
+
+        // If Zip64, need to read from Zip64 EOCD
+        if (cdOffset == 0xFFFFFFFF)
+        {
+            // Find Zip64 EOCD Locator
+            fs.Seek(-22 - 20, SeekOrigin.End);
+            var z64eocdlSig = br.ReadUInt32();
+            if (z64eocdlSig == 0x07064b50u)
+            {
+                br.ReadUInt32(); // disk number
+                var z64eocdOffset = br.ReadUInt64();
+                br.ReadUInt32(); // total disks
+
+                // Read Zip64 EOCD
+                fs.Seek((long)z64eocdOffset, SeekOrigin.Begin);
+                br.ReadUInt32(); // signature
+                br.ReadUInt64(); // size of EOCD64
+                br.ReadUInt16(); // version made by
+                br.ReadUInt16(); // version needed
+                br.ReadUInt32(); // disk number
+                br.ReadUInt32(); // disk with CD
+                br.ReadUInt64(); // entries on disk
+                br.ReadUInt64(); // total entries
+                br.ReadUInt64(); // CD size
+                cdOffset = (uint)br.ReadUInt64(); // CD offset
+            }
+        }
+
+        // Read Central Directory Header
+        fs.Seek(cdOffset, SeekOrigin.Begin);
+        var cdhSignature = br.ReadUInt32();
+        Assert.Equal(0x02014b50u, cdhSignature); // Central directory header signature
+
+        br.ReadUInt16(); // version made by
+        var cdhVersionNeeded = br.ReadUInt16();
+
+        // The versions should match when UseZip64 is true
+        Assert.Equal(lfhVersion, cdhVersionNeeded);
+    }
+
+    [Fact]
+    public void Zip64_Small_File_Without_UseZip64_Should_Have_Version_20()
+    {
+        // Create a zip without UseZip64
+        var filename = Path.Combine(SCRATCH2_FILES_PATH, "no_zip64_version_test.zip");
+
+        if (File.Exists(filename))
+        {
+            File.Delete(filename);
+        }
+
+        // Create archive without UseZip64
+        WriterOptions writerOptions = new ZipWriterOptions(CompressionType.Deflate)
+        {
+            LeaveStreamOpen = false,
+            UseZip64 = false,
+        };
+
+        ZipArchive zipArchive = ZipArchive.Create();
+        zipArchive.AddEntry("empty", new MemoryStream());
+        zipArchive.SaveTo(filename, writerOptions);
+
+        // Read the raw bytes
+        using var fs = File.OpenRead(filename);
+        using var br = new BinaryReader(fs);
+
+        // Read Local File Header version
+        var lfhSignature = br.ReadUInt32();
+        Assert.Equal(0x04034b50u, lfhSignature);
+        var lfhVersion = br.ReadUInt16();
+
+        // Read Central Directory Header version
+        fs.Seek(-22, SeekOrigin.End);
+        br.ReadUInt32(); // EOCD signature
+        br.ReadUInt16(); // disk number
+        br.ReadUInt16(); // disk with central dir
+        br.ReadUInt16(); // entries on this disk
+        br.ReadUInt16(); // total entries
+        br.ReadUInt32(); // CD size
+        var cdOffset = br.ReadUInt32();
+
+        fs.Seek(cdOffset, SeekOrigin.Begin);
+        var cdhSignature = br.ReadUInt32();
+        Assert.Equal(0x02014b50u, cdhSignature);
+        br.ReadUInt16(); // version made by
+        var cdhVersionNeeded = br.ReadUInt16();
+
+        // Both should be version 20 (or less)
+        Assert.True(lfhVersion <= 20);
+        Assert.Equal(lfhVersion, cdhVersionNeeded);
+    }
+
+    [Fact]
+    public void LZMA_Compression_Should_Use_Version_63()
+    {
+        // Create a zip with LZMA compression
+        var filename = Path.Combine(SCRATCH2_FILES_PATH, "lzma_version_test.zip");
+
+        if (File.Exists(filename))
+        {
+            File.Delete(filename);
+        }
+
+        WriterOptions writerOptions = new ZipWriterOptions(CompressionType.LZMA)
+        {
+            LeaveStreamOpen = false,
+            UseZip64 = false,
+        };
+
+        ZipArchive zipArchive = ZipArchive.Create();
+        var data = new byte[100];
+        new Random(42).NextBytes(data);
+        zipArchive.AddEntry("test.bin", new MemoryStream(data));
+        zipArchive.SaveTo(filename, writerOptions);
+
+        // Read the raw bytes
+        using var fs = File.OpenRead(filename);
+        using var br = new BinaryReader(fs);
+
+        // Read Local File Header version
+        var lfhSignature = br.ReadUInt32();
+        Assert.Equal(0x04034b50u, lfhSignature);
+        var lfhVersion = br.ReadUInt16();
+
+        // Read Central Directory Header version
+        fs.Seek(-22, SeekOrigin.End);
+        br.ReadUInt32(); // EOCD signature
+        br.ReadUInt16(); // disk number
+        br.ReadUInt16(); // disk with central dir
+        br.ReadUInt16(); // entries on this disk
+        br.ReadUInt16(); // total entries
+        br.ReadUInt32(); // CD size
+        var cdOffset = br.ReadUInt32();
+
+        fs.Seek(cdOffset, SeekOrigin.Begin);
+        var cdhSignature = br.ReadUInt32();
+        Assert.Equal(0x02014b50u, cdhSignature);
+        br.ReadUInt16(); // version made by
+        var cdhVersionNeeded = br.ReadUInt16();
+
+        // Both should be version 63 for LZMA
+        Assert.Equal(63, lfhVersion);
+        Assert.Equal(lfhVersion, cdhVersionNeeded);
+    }
+
+    [Fact]
+    public void PPMd_Compression_Should_Use_Version_63()
+    {
+        // Create a zip with PPMd compression
+        var filename = Path.Combine(SCRATCH2_FILES_PATH, "ppmd_version_test.zip");
+
+        if (File.Exists(filename))
+        {
+            File.Delete(filename);
+        }
+
+        WriterOptions writerOptions = new ZipWriterOptions(CompressionType.PPMd)
+        {
+            LeaveStreamOpen = false,
+            UseZip64 = false,
+        };
+
+        ZipArchive zipArchive = ZipArchive.Create();
+        var data = new byte[100];
+        new Random(42).NextBytes(data);
+        zipArchive.AddEntry("test.bin", new MemoryStream(data));
+        zipArchive.SaveTo(filename, writerOptions);
+
+        // Read the raw bytes
+        using var fs = File.OpenRead(filename);
+        using var br = new BinaryReader(fs);
+
+        // Read Local File Header version
+        var lfhSignature = br.ReadUInt32();
+        Assert.Equal(0x04034b50u, lfhSignature);
+        var lfhVersion = br.ReadUInt16();
+
+        // Read Central Directory Header version
+        fs.Seek(-22, SeekOrigin.End);
+        br.ReadUInt32(); // EOCD signature
+        br.ReadUInt16(); // disk number
+        br.ReadUInt16(); // disk with central dir
+        br.ReadUInt16(); // entries on this disk
+        br.ReadUInt16(); // total entries
+        br.ReadUInt32(); // CD size
+        var cdOffset = br.ReadUInt32();
+
+        fs.Seek(cdOffset, SeekOrigin.Begin);
+        var cdhSignature = br.ReadUInt32();
+        Assert.Equal(0x02014b50u, cdhSignature);
+        br.ReadUInt16(); // version made by
+        var cdhVersionNeeded = br.ReadUInt16();
+
+        // Both should be version 63 for PPMd
+        Assert.Equal(63, lfhVersion);
+        Assert.Equal(lfhVersion, cdhVersionNeeded);
+    }
+
+    [Fact]
+    public void Zip64_Multiple_Small_Files_With_UseZip64_Should_Have_Matching_Versions()
+    {
+        // Create a zip with UseZip64=true but with multiple small files
+        var filename = Path.Combine(SCRATCH2_FILES_PATH, "zip64_version_multiple_test.zip");
+
+        if (File.Exists(filename))
+        {
+            File.Delete(filename);
+        }
+
+        WriterOptions writerOptions = new ZipWriterOptions(CompressionType.Deflate)
+        {
+            LeaveStreamOpen = false,
+            UseZip64 = true,
+        };
+
+        ZipArchive zipArchive = ZipArchive.Create();
+        for (int i = 0; i < 5; i++)
+        {
+            var data = new byte[100];
+            new Random(i).NextBytes(data);
+            zipArchive.AddEntry($"file{i}.bin", new MemoryStream(data));
+        }
+        zipArchive.SaveTo(filename, writerOptions);
+
+        // Verify that all entries have matching versions
+        using var fs = File.OpenRead(filename);
+        using var br = new BinaryReader(fs);
+
+        // Read all LFH versions
+        var lfhVersions = new System.Collections.Generic.List<ushort>();
+        while (true)
+        {
+            var sig = br.ReadUInt32();
+            if (sig == 0x04034b50u) // LFH signature
+            {
+                var version = br.ReadUInt16();
+                lfhVersions.Add(version);
+
+                // Skip rest of LFH
+                br.ReadUInt16(); // flags
+                br.ReadUInt16(); // compression
+                br.ReadUInt32(); // mod time
+                br.ReadUInt32(); // crc
+                br.ReadUInt32(); // compressed size
+                br.ReadUInt32(); // uncompressed size
+                var fnLen = br.ReadUInt16();
+                var extraLen = br.ReadUInt16();
+                fs.Seek(fnLen + extraLen, SeekOrigin.Current);
+
+                // Skip compressed data by reading compressed size from extra field if zip64
+                // For simplicity in this test, we'll just find the next signature
+                var found = false;
+
+                while (fs.Position < fs.Length - 4)
+                {
+                    var b = br.ReadByte();
+                    if (b == 0x50)
+                    {
+                        var nextBytes = br.ReadBytes(3);
+                        if (
+                            (nextBytes[0] == 0x4b && nextBytes[1] == 0x03 && nextBytes[2] == 0x04)
+                            || // LFH
+                            (nextBytes[0] == 0x4b && nextBytes[1] == 0x01 && nextBytes[2] == 0x02)
+                        ) // CDH
+                        {
+                            fs.Seek(-4, SeekOrigin.Current);
+                            found = true;
+                            break;
+                        }
+                    }
+                }
+
+                if (!found)
+                {
+                    break;
+                }
+            }
+            else if (sig == 0x02014b50u) // CDH signature
+            {
+                break; // Reached central directory
+            }
+            else
+            {
+                break; // Unknown signature
+            }
+        }
+
+        // Find Central Directory
+        fs.Seek(-22, SeekOrigin.End);
+        br.ReadUInt32(); // EOCD signature
+        br.ReadUInt16(); // disk number
+        br.ReadUInt16(); // disk with central dir
+        br.ReadUInt16(); // entries on this disk
+        var totalEntries = br.ReadUInt16();
+        br.ReadUInt32(); // CD size
+        var cdOffset = br.ReadUInt32();
+
+        // Check if we need Zip64 EOCD
+        if (cdOffset == 0xFFFFFFFF)
+        {
+            fs.Seek(-22 - 20, SeekOrigin.End);
+            var z64eocdlSig = br.ReadUInt32();
+            if (z64eocdlSig == 0x07064b50u)
+            {
+                br.ReadUInt32(); // disk number
+                var z64eocdOffset = br.ReadUInt64();
+                fs.Seek((long)z64eocdOffset, SeekOrigin.Begin);
+                br.ReadUInt32(); // signature
+                br.ReadUInt64(); // size
+                br.ReadUInt16(); // version made by
+                br.ReadUInt16(); // version needed
+                br.ReadUInt32(); // disk number
+                br.ReadUInt32(); // disk with CD
+                br.ReadUInt64(); // entries on disk
+                totalEntries = (ushort)br.ReadUInt64(); // total entries
+                br.ReadUInt64(); // CD size
+                cdOffset = (uint)br.ReadUInt64(); // CD offset
+            }
+        }
+
+        // Read CDH versions
+        fs.Seek(cdOffset, SeekOrigin.Begin);
+        var cdhVersions = new System.Collections.Generic.List<ushort>();
+        for (int i = 0; i < totalEntries; i++)
+        {
+            var sig = br.ReadUInt32();
+            Assert.Equal(0x02014b50u, sig);
+            br.ReadUInt16(); // version made by
+            var version = br.ReadUInt16();
+            cdhVersions.Add(version);
+
+            // Skip rest of CDH
+            br.ReadUInt16(); // flags
+            br.ReadUInt16(); // compression
+            br.ReadUInt32(); // mod time
+            br.ReadUInt32(); // crc
+            br.ReadUInt32(); // compressed size
+            br.ReadUInt32(); // uncompressed size
+            var fnLen = br.ReadUInt16();
+            var extraLen = br.ReadUInt16();
+            var commentLen = br.ReadUInt16();
+            br.ReadUInt16(); // disk number start
+            br.ReadUInt16(); // internal attributes
+            br.ReadUInt32(); // external attributes
+            br.ReadUInt32(); // LFH offset
+            fs.Seek(fnLen + extraLen + commentLen, SeekOrigin.Current);
+        }
+
+        // Verify all versions match
+        Assert.Equal(lfhVersions.Count, cdhVersions.Count);
+        for (int i = 0; i < lfhVersions.Count; i++)
+        {
+            Assert.Equal(lfhVersions[i], cdhVersions[i]);
+        }
+    }
+}

tests/SharpCompress.Test/Zip/ZipArchiveTests.cs

@@ -2,6 +2,7 @@ using System;
 using System.IO;
 using System.Linq;
 using System.Text;
+using System.Threading.Tasks;
 using SharpCompress.Archives;
 using SharpCompress.Archives.Zip;
 using SharpCompress.Common;
@@ -88,6 +89,10 @@ public class ZipArchiveTests : ArchiveTests
     [Fact]
     public void Zip_Deflate_ArchiveFileRead() => ArchiveFileRead("Zip.deflate.zip");
 
+    [Fact]
+    public Task Zip_Deflate_ArchiveFileRead_Multithreaded() =>
+        ArchiveFileRead_Multithreaded("Zip.deflate.zip");
+
     [Fact]
     public void Zip_Deflate_ArchiveExtractToDirectory() =>
         ArchiveExtractToDirectory("Zip.deflate.zip");

tests/SharpCompress.Test/packages.lock.json

@@ -4,9 +4,9 @@
     ".NETFramework,Version=v4.8": {
       "AwesomeAssertions": {
         "type": "Direct",
-        "requested": "[9.2.1, )",
-        "resolved": "9.2.1",
-        "contentHash": "lbwhyQNXxxEGx4oCbFqNfFy2DsywsvNhN6qoOjY4wwhMgI2L9+YrxjyF/M0io99yrvWV1Cjj12LP2QGcC43Uhw==",
+        "requested": "[9.3.0, )",
+        "resolved": "9.3.0",
+        "contentHash": "8lGLYap2ec2gNLgjf2xKZaKLpQ7j36oJvrYzBVVpNAumqnxRdevqqhEF66qxE92f8y2+zsbQ061DeHG61ZhzaQ==",
         "dependencies": {
           "System.Threading.Tasks.Extensions": "4.5.4"
         }
@@ -199,9 +199,9 @@
     "net8.0": {
       "AwesomeAssertions": {
         "type": "Direct",
-        "requested": "[9.2.1, )",
-        "resolved": "9.2.1",
-        "contentHash": "lbwhyQNXxxEGx4oCbFqNfFy2DsywsvNhN6qoOjY4wwhMgI2L9+YrxjyF/M0io99yrvWV1Cjj12LP2QGcC43Uhw=="
+        "requested": "[9.3.0, )",
+        "resolved": "9.3.0",
+        "contentHash": "8lGLYap2ec2gNLgjf2xKZaKLpQ7j36oJvrYzBVVpNAumqnxRdevqqhEF66qxE92f8y2+zsbQ061DeHG61ZhzaQ=="
       },
       "Microsoft.NET.Test.Sdk": {
         "type": "Direct",