From 2f3d11ca61c908fde0228215ab7a418b85b8d03e Mon Sep 17 00:00:00 2001
From: Adam Hathcock <adam@hathcock.uk>
Date: Thu, 30 Apr 2026 13:57:03 +0100
Subject: [PATCH] Rationalize AsyncDisposable

---
 src/SharpCompress/Writers/GZip/GZipWriter.cs  | 21 +++++++++++++++++
 src/SharpCompress/Writers/IAsyncWriter.cs     | 23 +++++++++++++++++++
 src/SharpCompress/Writers/IWriter.cs          | 18 ---------------
 tests/SharpCompress.Test/GZip/AsyncTests.cs   |  3 +--
 .../GZip/GZipWriterAsyncTests.cs              |  9 ++++++--
 5 files changed, 52 insertions(+), 22 deletions(-)
 create mode 100644 src/SharpCompress/Writers/IAsyncWriter.cs

diff --git a/src/SharpCompress/Writers/GZip/GZipWriter.cs b/src/SharpCompress/Writers/GZip/GZipWriter.cs
index eebac616..e25e4f9c 100644
--- a/src/SharpCompress/Writers/GZip/GZipWriter.cs
+++ b/src/SharpCompress/Writers/GZip/GZipWriter.cs
@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Threading.Tasks;
 using SharpCompress.Common;
 using SharpCompress.Compressors;
 using SharpCompress.Compressors.Deflate;
@@ -48,6 +49,26 @@ public sealed partial class GZipWriter : AbstractWriter
         base.Dispose(isDisposing);
     }
 
+#pragma warning disable CA2215 // base.DisposeAsync() calls the sync Dispose path for writers.
+    public override async ValueTask DisposeAsync()
+    {
+        if (_isDisposed)
+        {
+            return;
+        }
+
+        GC.SuppressFinalize(this);
+        _isDisposed = true;
+
+#if !LEGACY_DOTNET || NETSTANDARD2_1
+        await OutputStream.NotNull().DisposeAsync().ConfigureAwait(false);
+#else
+        OutputStream.NotNull().Dispose();
+        await Task.CompletedTask.ConfigureAwait(false);
+#endif
+    }
+#pragma warning restore CA2215
+
     public override void Write(string filename, Stream source, DateTime? modificationTime)
     {
         if (_wroteToStream)
diff --git a/src/SharpCompress/Writers/IAsyncWriter.cs b/src/SharpCompress/Writers/IAsyncWriter.cs
new file mode 100644
index 00000000..121b5ebc
--- /dev/null
+++ b/src/SharpCompress/Writers/IAsyncWriter.cs
@@ -0,0 +1,23 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SharpCompress.Common;
+
+namespace SharpCompress.Writers;
+
+public interface IAsyncWriter : IAsyncDisposable
+{
+    ArchiveType WriterType { get; }
+    ValueTask WriteAsync(
+        string filename,
+        Stream source,
+        DateTime? modificationTime,
+        CancellationToken cancellationToken = default
+    );
+    ValueTask WriteDirectoryAsync(
+        string directoryName,
+        DateTime? modificationTime,
+        CancellationToken cancellationToken = default
+    );
+}
diff --git a/src/SharpCompress/Writers/IWriter.cs b/src/SharpCompress/Writers/IWriter.cs
index 648c0fe0..4142d602 100644
--- a/src/SharpCompress/Writers/IWriter.cs
+++ b/src/SharpCompress/Writers/IWriter.cs
@@ -1,7 +1,5 @@
 using System;
 using System.IO;
-using System.Threading;
-using System.Threading.Tasks;
 using SharpCompress.Common;
 
 namespace SharpCompress.Writers;
@@ -12,19 +10,3 @@ public interface IWriter : IDisposable
     void Write(string filename, Stream source, DateTime? modificationTime);
     void WriteDirectory(string directoryName, DateTime? modificationTime);
 }
-
-public interface IAsyncWriter : IDisposable, IAsyncDisposable
-{
-    ArchiveType WriterType { get; }
-    ValueTask WriteAsync(
-        string filename,
-        Stream source,
-        DateTime? modificationTime,
-        CancellationToken cancellationToken = default
-    );
-    ValueTask WriteDirectoryAsync(
-        string directoryName,
-        DateTime? modificationTime,
-        CancellationToken cancellationToken = default
-    );
-}
diff --git a/tests/SharpCompress.Test/GZip/AsyncTests.cs b/tests/SharpCompress.Test/GZip/AsyncTests.cs
index 150ab4ae..9a0a8590 100644
--- a/tests/SharpCompress.Test/GZip/AsyncTests.cs
+++ b/tests/SharpCompress.Test/GZip/AsyncTests.cs
@@ -100,11 +100,10 @@ public class AsyncTests : TestBase
 
 #if NETFRAMEWORK
         using (var stream = File.Create(outputPath))
-        using (
 #else
         await using (var stream = File.Create(outputPath))
-        await using (
 #endif
+        await using (
             var writer = await WriterFactory.OpenAsyncWriter(
                 new AsyncOnlyStream(stream),
                 ArchiveType.Zip,
diff --git a/tests/SharpCompress.Test/GZip/GZipWriterAsyncTests.cs b/tests/SharpCompress.Test/GZip/GZipWriterAsyncTests.cs
index 86c2cf35..0cfda96a 100644
--- a/tests/SharpCompress.Test/GZip/GZipWriterAsyncTests.cs
+++ b/tests/SharpCompress.Test/GZip/GZipWriterAsyncTests.cs
@@ -23,7 +23,7 @@ public class GZipWriterAsyncTests : WriterTests
                 FileAccess.Write
             )
         )
-        using (
+        await using (
             var writer = await WriterFactory.OpenAsyncWriter(
                 new AsyncOnlyStream(stream),
                 ArchiveType.GZip,
@@ -49,7 +49,12 @@ public class GZipWriterAsyncTests : WriterTests
                 FileAccess.Write
             )
         )
-        using (var writer = new GZipWriter(new AsyncOnlyStream(stream)))
+#if NETFRAMEWORK
+        using (
+#else
+        await using (
+#endif
+            var writer = new GZipWriter(new AsyncOnlyStream(stream)))
         {
             await writer.WriteAsync("Tar.tar", Path.Combine(TEST_ARCHIVES_PATH, "Tar.tar"));
         }