From 4c8aefb2ce7e00b6b19ce00fdd11e564d1b8dcc4 Mon Sep 17 00:00:00 2001
From: Victor Irzak <victor.irzak@zomp.com>
Date: Tue, 28 Jul 2026 00:51:14 -0400
Subject: [PATCH 1/2] Cover the documentation which is copied into a generated
 file

Two cases, both recorded here as the generator currently handles them so that
the fix shows what changes:

A cref is resolved against the file it lands in, not the file it was written
in. The generated file carries neither the using directives from the top of
the source file nor those inside its namespace, so a cref which relied on one
goes unresolved and the compiler reports CS1574 - a build failure for the many
projects which treat warnings as errors.

A method which returned a task returns nothing once synchronized, so a
<returns> element describing that task describes something which no longer
exists. The element is copied across regardless.

Generated with Claude Code
---
 ...NothingIsReturned#CountAsync.g.verified.cs | 11 ++++
 ...nNothingIsReturned#ReadAsync.g.verified.cs |  8 +++
 ...tationCrefsResolve#SendAsync.g.verified.cs | 15 +++++
 tests/Generator.Tests/UnitTests.cs            | 57 +++++++++++++++++++
 4 files changed, 91 insertions(+)
 create mode 100644 tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#CountAsync.g.verified.cs
 create mode 100644 tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#ReadAsync.g.verified.cs
 create mode 100644 tests/Generator.Tests/Snapshots/UnitTests.KeepUsingsSoDocumentationCrefsResolve#SendAsync.g.verified.cs

diff --git a/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#CountAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#CountAsync.g.verified.cs
new file mode 100644
index 0000000..d8f04fe
--- /dev/null
+++ b/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#CountAsync.g.verified.cs
@@ -0,0 +1,11 @@
+//HintName: Test.Class.CountAsync.g.cs
+/// <summary>
+/// Counts the values.
+/// </summary>
+/// <param name="input">Where to read from.</param>
+/// <returns>A <see cref="Task"/> whose result is the number of values.</returns>
+public int Count(global::System.IO.Stream input)
+{
+    input.Flush();
+    return 0;
+}
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#ReadAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#ReadAsync.g.verified.cs
new file mode 100644
index 0000000..6ef1c77
--- /dev/null
+++ b/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#ReadAsync.g.verified.cs
@@ -0,0 +1,8 @@
+//HintName: Test.Class.ReadAsync.g.cs
+/// <summary>
+/// Reads a value.
+/// </summary>
+/// <param name="input">Where to read from.</param>
+/// <returns>A <see cref="Task"/> that represents the asynchronous read.</returns>
+public void Read(global::System.IO.Stream input)
+    => input.Flush();
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.KeepUsingsSoDocumentationCrefsResolve#SendAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.KeepUsingsSoDocumentationCrefsResolve#SendAsync.g.verified.cs
new file mode 100644
index 0000000..92f2ca0
--- /dev/null
+++ b/tests/Generator.Tests/Snapshots/UnitTests.KeepUsingsSoDocumentationCrefsResolve#SendAsync.g.verified.cs
@@ -0,0 +1,15 @@
+//HintName: Test.Class.SendAsync.g.cs
+// <auto-generated/>
+#nullable enable
+namespace Test
+{
+    public partial class Class
+    {
+        /// <summary>
+        /// Sends a <see cref="StringBuilder"/> over a <see cref="Socket"/>.
+        /// </summary>
+        /// <param name="input">Where to read from.</param>
+        public void Send(global::System.IO.Stream input)
+            => input.Flush();
+    }
+}
diff --git a/tests/Generator.Tests/UnitTests.cs b/tests/Generator.Tests/UnitTests.cs
index a335e80..326fdb6 100644
--- a/tests/Generator.Tests/UnitTests.cs
+++ b/tests/Generator.Tests/UnitTests.cs
@@ -853,6 +853,63 @@ public async Task ReadAsync(Stream input, CancellationToken cancellationToken =
 }
 """.Verify(sourceType: SourceType.Full, documentationMode: DocumentationMode.None);
 
+    /// <summary>
+    /// A cref is resolved against the file it lands in, so the generated file needs the using
+    /// directives which were in scope where the documentation was written. Without them a
+    /// project building with warnings as errors fails on CS1574.
+    /// </summary>
+    /// <returns>A task.</returns>
+    [Fact]
+    public Task KeepUsingsSoDocumentationCrefsResolve() => """
+using System.Text;
+
+namespace Test
+{
+    using System.Net.Sockets;
+
+    public partial class Class
+    {
+        /// <summary>
+        /// Sends a <see cref="StringBuilder"/> over a <see cref="Socket"/>.
+        /// </summary>
+        /// <param name="input">Where to read from.</param>
+        /// <param name="cancellationToken">Cancellation token.</param>
+        [Zomp.SyncMethodGenerator.CreateSyncVersion]
+        public async Task SendAsync(Stream input, CancellationToken cancellationToken = default)
+            => await input.FlushAsync(cancellationToken);
+    }
+}
+""".Verify(sourceType: SourceType.Full);
+
+    /// <summary>
+    /// The task a method returned is not returned by its synchronized version, so documentation
+    /// describing that task describes nothing. Documentation of a value which survives stays.
+    /// </summary>
+    /// <returns>A task.</returns>
+    [Fact]
+    public Task DropReturnsDocumentationWhenNothingIsReturned() => """
+/// <summary>
+/// Reads a value.
+/// </summary>
+/// <param name="input">Where to read from.</param>
+/// <returns>A <see cref="Task"/> that represents the asynchronous read.</returns>
+[Zomp.SyncMethodGenerator.CreateSyncVersion]
+public async Task ReadAsync(Stream input)
+    => await input.FlushAsync();
+
+/// <summary>
+/// Counts the values.
+/// </summary>
+/// <param name="input">Where to read from.</param>
+/// <returns>A <see cref="Task"/> whose result is the number of values.</returns>
+[Zomp.SyncMethodGenerator.CreateSyncVersion]
+public async Task<int> CountAsync(Stream input)
+{
+    await input.FlushAsync();
+    return 0;
+}
+""".Verify();
+
     [Fact]
     public Task VerifyParamHandling() => $$"""
 static byte[] HelperMethod(params int[] myParams) => null;

From fbda0c4fd7f1a1d54a6db2cc59bf356961838bbe Mon Sep 17 00:00:00 2001
From: Victor Irzak <victor.irzak@zomp.com>
Date: Tue, 28 Jul 2026 00:52:47 -0400
Subject: [PATCH 2/2] Carry the source file's using directives into the
 generated file

Documentation is copied into the generated file verbatim, and a cref in it is
resolved against the file it lands in. Whatever the crefs relied on being in
scope has to land there too, or the compiler reports CS1574 for each one and a
project which treats warnings as errors fails to build.

The directives are emitted on the side of the namespace they were declared on:
one written inside a namespace may name another only relatively, and would not
resolve from above it. The generated code itself is fully qualified and does
not need any of them, so nothing here changes what the code means.

Also drop a <returns> element when the synchronized method returns nothing,
since the task it describes is no longer returned. A <returns> describing a
value which survives is kept: it is imprecise about the task it mentions, but
dropping it would say less than saying it imprecisely.

Generated with Claude Code
---
 .../AsyncToSyncRewriter.cs                    | 14 +++++++
 .../MethodToGenerate.cs                       |  4 ++
 .../SourceGenerationHelper.cs                 | 39 ++++++++++++++++++-
 .../SyncMethodSourceGenerator.cs              | 33 +++++++++++++++-
 ...allers.ext.CopyAndDrainAsync.g.verified.cs |  2 +
 ...mCallers.ext.DrainTwiceAsync.g.verified.cs |  2 +
 ...cde8.QueryableExtensionAsync.g.verified.cs |  6 +++
 ...ns.HasGeneric2ExtensionAsync.g.verified.cs | 33 +++++++++-------
 ...ons.HasGenericExtensionAsync.g.verified.cs | 33 +++++++++-------
 ...inedTypes#N1.Class.FillAsync.g.verified.cs | 32 ++++++++-------
 ...GetConfiguredAsyncEnumerator.g.verified.cs | 25 ++++++------
 .../TypeTests.EnumPattern#g.verified.cs       | 14 ++++++-
 ...nNothingIsReturned#ReadAsync.g.verified.cs |  1 -
 ...Pattern#M.B.DoSomethingAsync.g.verified.cs |  2 +
 ...ression#M.B.DoSomethingAsync.g.verified.cs |  2 +
 ...Attribute#ReadSomeBytesAsync.g.verified.cs | 27 +++++++------
 ...tationCrefsResolve#SendAsync.g.verified.cs |  5 +++
 ...ts.Preprocessor#WrappedAsync.g.verified.cs | 26 +++++++------
 ...aticUsings#N1.C1.MethodAsync.g.verified.cs | 29 +++++++-------
 ...ensionMethods.OneParamsAsync.g.verified.cs | 26 ++++++++-----
 ...ensionMethods.TwoParamsAsync.g.verified.cs | 26 ++++++++-----
 ...nsionMethods.ZeroParamsAsync.g.verified.cs | 26 ++++++++-----
 22 files changed, 286 insertions(+), 121 deletions(-)

diff --git a/src/Zomp.SyncMethodGenerator/AsyncToSyncRewriter.cs b/src/Zomp.SyncMethodGenerator/AsyncToSyncRewriter.cs
index 0b1aa26..6c0a2b2 100644
--- a/src/Zomp.SyncMethodGenerator/AsyncToSyncRewriter.cs
+++ b/src/Zomp.SyncMethodGenerator/AsyncToSyncRewriter.cs
@@ -957,6 +957,14 @@ bool RemoveType(TypeSyntax z, int index) =>
         var originalName = @base.Identifier.Text;
         var newName = RemoveAsync(originalName);
 
+        // A method which returned a task returns nothing once it is synchronized, so whatever
+        // its documentation said about the task it returned no longer describes anything. The
+        // documentation of a value which survives is left alone: it is imprecise about the task
+        // it mentions, but dropping it would say less than saying it imprecisely.
+        var returnsNothing = GetReturnType(@base.ReturnType, symbol)
+            is PredefinedTypeSyntax { Keyword.RawKind: (int)SyntaxKind.VoidKeyword }
+            or IdentifierNameSyntax { Identifier.ValueText: "void" };
+
         // Documentation
         var trivia = node.GetLeadingTrivia();
         var newTriviaList = trivia;
@@ -982,6 +990,12 @@ bool RemoveType(TypeSyntax z, int index) =>
                         indicesToRemove.Add(i - 1); // preceding slashes
                         indicesToRemove.Add(i);
                     }
+                    else if (returnsNothing
+                        && xes.StartTag.Name.LocalName.ValueText.Equals("returns", StringComparison.Ordinal))
+                    {
+                        indicesToRemove.Add(i - 1); // preceding slashes
+                        indicesToRemove.Add(i);
+                    }
                 }
 
                 ++i;
diff --git a/src/Zomp.SyncMethodGenerator/MethodToGenerate.cs b/src/Zomp.SyncMethodGenerator/MethodToGenerate.cs
index 90d7b2b..6094d2b 100644
--- a/src/Zomp.SyncMethodGenerator/MethodToGenerate.cs
+++ b/src/Zomp.SyncMethodGenerator/MethodToGenerate.cs
@@ -5,6 +5,8 @@
 /// </summary>
 /// <param name="Index">Index of the method in the source file.</param>
 /// <param name="Namespaces">List of namespaces this method is under.</param>
+/// <param name="OuterUsings">Using directives the source file declares outside its namespace.</param>
+/// <param name="InnerUsings">Using directives the source file declares inside its namespace.</param>
 /// <param name="IsNamespaceFileScoped">True if namespace is file scoped.</param>
 /// <param name="IsCSharp14Extension">True if this is C# 14 extension.</param>
 /// <param name="Parents">List of classes/structs/records this method belongs to starting from the outer-most class.</param>
@@ -17,6 +19,8 @@
 internal sealed record MethodToGenerate(
     int Index,
     EquatableArray<string> Namespaces,
+    EquatableArray<string> OuterUsings,
+    EquatableArray<string> InnerUsings,
     bool IsNamespaceFileScoped,
     bool IsCSharp14Extension,
     EquatableArray<MethodParentDeclaration> Parents,
diff --git a/src/Zomp.SyncMethodGenerator/SourceGenerationHelper.cs b/src/Zomp.SyncMethodGenerator/SourceGenerationHelper.cs
index e3d2575..bd736fb 100644
--- a/src/Zomp.SyncMethodGenerator/SourceGenerationHelper.cs
+++ b/src/Zomp.SyncMethodGenerator/SourceGenerationHelper.cs
@@ -100,6 +100,24 @@ internal static string GenerateExtensionClass(MethodToGenerate methodToGenerate)
             }
         }
 
+        // Directives which were written inside the namespace are emitted inside it, at the
+        // innermost level. One which names a namespace relatively still resolves from there.
+        foreach (var @using in methodToGenerate.InnerUsings)
+        {
+            _ = sbBegin.Append($$"""
+{{new string(' ', 4 * i)}}{{@using}}
+
+""");
+        }
+
+        if (!methodToGenerate.InnerUsings.IsEmpty)
+        {
+            _ = sbBegin.Append("""
+
+
+""");
+        }
+
         // Handle classes
         foreach (var parent in methodToGenerate.Parents)
         {
@@ -136,11 +154,30 @@ internal static string GenerateExtensionClass(MethodToGenerate methodToGenerate)
             ++i;
         }
 
+        var sbOuterUsings = new StringBuilder();
+        foreach (var @using in methodToGenerate.OuterUsings)
+        {
+            if (sbOuterUsings.Length == 0)
+            {
+                // Separates the directives from the header above them.
+                _ = sbOuterUsings.Append("""
+
+
+
+""");
+            }
+
+            _ = sbOuterUsings.Append($$"""
+{{@using}}
+
+""");
+        }
+
         var beforeNamespace = $"""
 // <auto-generated/>{(methodToGenerate.DisableNullable ? string.Empty : """
 
 #nullable enable
-""")}
+""")}{sbOuterUsings}
 """;
 
         return methodToGenerate.IsNamespaceFileScoped ? $$"""
diff --git a/src/Zomp.SyncMethodGenerator/SyncMethodSourceGenerator.cs b/src/Zomp.SyncMethodGenerator/SyncMethodSourceGenerator.cs
index a3d69fa..3b76bfc 100644
--- a/src/Zomp.SyncMethodGenerator/SyncMethodSourceGenerator.cs
+++ b/src/Zomp.SyncMethodGenerator/SyncMethodSourceGenerator.cs
@@ -372,6 +372,15 @@ private static string Hash(string value)
         var isNamespaceFileScoped = false;
         var namespaces = ImmutableArray.CreateBuilder<string>();
 
+        // Documentation comments are copied across verbatim, and a cref in one is resolved
+        // against the file it lands in rather than the file it was written in. Without the
+        // using directives which were in scope where it was written, every cref which relied on
+        // one goes unresolved, which a project building with warnings as errors reads as a
+        // build failure. The directives are kept on the side of the namespace they were
+        // declared on, since one declared inside a namespace may name it only relatively.
+        var outerUsings = ImmutableArray.CreateBuilder<string>();
+        var innerUsings = ImmutableArray.CreateBuilder<string>();
+
         if (!hasErrors)
         {
             while (node is not null and not CompilationUnitSyntax)
@@ -380,9 +389,11 @@ private static string Hash(string value)
                 {
                     case NamespaceDeclarationSyntax nds:
                         namespaces.Insert(0, nds.Name.ToString());
+                        InsertUsings(innerUsings, nds.Usings);
                         break;
                     case FileScopedNamespaceDeclarationSyntax file:
                         namespaces.Add(file.Name.ToString());
+                        InsertUsings(innerUsings, file.Usings);
                         isNamespaceFileScoped = true;
                         break;
                     default:
@@ -391,6 +402,11 @@ private static string Hash(string value)
 
                 node = node.Parent;
             }
+
+            if (node is CompilationUnitSyntax compilationUnit)
+            {
+                InsertUsings(outerUsings, compilationUnit.Usings);
+            }
         }
 
 #if ROSLYN_5_0_OR_GREATER
@@ -400,11 +416,26 @@ private static string Hash(string value)
 #endif
         var signature = BuildSignature(sn, namespaces, classes, methodDeclarationSyntax);
 
-        var result = new MethodToGenerate(index, namespaces.ToImmutable(), isNamespaceFileScoped, isCSharp14Extension, classes.ToImmutable(), methodDeclarationSyntax.Identifier.ValueText, content, disableNullable, rewriter.Diagnostics, hasErrors, signature);
+        var result = new MethodToGenerate(index, namespaces.ToImmutable(), outerUsings.ToImmutable(), innerUsings.ToImmutable(), isNamespaceFileScoped, isCSharp14Extension, classes.ToImmutable(), methodDeclarationSyntax.Identifier.ValueText, content, disableNullable, rewriter.Diagnostics, hasErrors, signature);
 
         return result;
     }
 
+    /// <summary>
+    /// Records the directives, innermost first, so that walking outwards from the method builds
+    /// them up in the order they were written.
+    /// </summary>
+    /// <param name="destination">Collected directives.</param>
+    /// <param name="usings">Directives declared at one level.</param>
+    private static void InsertUsings(ImmutableArray<string>.Builder destination, SyntaxList<UsingDirectiveSyntax> usings)
+    {
+        var index = 0;
+        foreach (var @using in usings)
+        {
+            destination.Insert(index++, @using.ToString());
+        }
+    }
+
     /// <summary>
     /// Describes the method which is about to be emitted, precisely enough to tell whether two
     /// of them would declare the same member. The rewritten declaration is used rather than the
diff --git a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.CSharp_14_ExtensionCallingAnotherExtension#Callers.StreamCallers.ext.CopyAndDrainAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.CSharp_14_ExtensionCallingAnotherExtension#Callers.StreamCallers.ext.CopyAndDrainAsync.g.verified.cs
index 50c07d8..e52af22 100644
--- a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.CSharp_14_ExtensionCallingAnotherExtension#Callers.StreamCallers.ext.CopyAndDrainAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.CSharp_14_ExtensionCallingAnotherExtension#Callers.StreamCallers.ext.CopyAndDrainAsync.g.verified.cs
@@ -3,6 +3,8 @@
 #nullable enable
 namespace Callers
 {
+    using Helpers;
+
     public static partial class StreamCallers
     {
         extension(global::System.IO.Stream stream)
diff --git a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.CSharp_14_ExtensionUnwrapsOntoOneLine#Callers.StreamCallers.ext.DrainTwiceAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.CSharp_14_ExtensionUnwrapsOntoOneLine#Callers.StreamCallers.ext.DrainTwiceAsync.g.verified.cs
index 6149c8d..1b475ad 100644
--- a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.CSharp_14_ExtensionUnwrapsOntoOneLine#Callers.StreamCallers.ext.DrainTwiceAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.CSharp_14_ExtensionUnwrapsOntoOneLine#Callers.StreamCallers.ext.DrainTwiceAsync.g.verified.cs
@@ -3,6 +3,8 @@
 #nullable enable
 namespace Callers
 {
+    using Helpers;
+
     public static partial class StreamCallers
     {
         extension(global::System.IO.Stream stream)
diff --git a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.EntityFrameworkQueryableExtensions#Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQuery_0f26cde8.QueryableExtensionAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.EntityFrameworkQueryableExtensions#Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQuery_0f26cde8.QueryableExtensionAsync.g.verified.cs
index 2377bed..fe5a317 100644
--- a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.EntityFrameworkQueryableExtensions#Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQuery_0f26cde8.QueryableExtensionAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.EntityFrameworkQueryableExtensions#Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQuery_0f26cde8.QueryableExtensionAsync.g.verified.cs
@@ -1,8 +1,14 @@
 //HintName: Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQuery_0f26cde8.QueryableExtensionAsync.g.cs
 // <auto-generated/>
 #nullable enable
+
+using System.Threading;
+using System.Threading.Tasks;
+
 namespace Zomp.SyncMethodGenerator.IntegrationTests
 {
+    using Microsoft.EntityFrameworkCore;
+
     public partial class EntityFrameworkQueryableExtensions
     {
         public int QueryableExtension(global::Microsoft.EntityFrameworkCore.DbContext dbContext)
diff --git a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.UnwrapGenericExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGeneric2ExtensionAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.UnwrapGenericExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGeneric2ExtensionAsync.g.verified.cs
index 16675a6..52b17d6 100644
--- a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.UnwrapGenericExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGeneric2ExtensionAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.UnwrapGenericExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGeneric2ExtensionAsync.g.verified.cs
@@ -1,13 +1,20 @@
-//HintName: Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGeneric2ExtensionAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace Zomp.SyncMethodGenerator.IntegrationTests
-{
-    partial class Extensions
-    {
-        public static void HasGeneric2Extension(object o)
-        {
-            var z = global::Extensi.ons123.MyExtensionClass.TryGetValue<global::System.Drawing.Point, global::System.Drawing.PointF>(o, out var _, out var _1);
-        }
-    }
-}
+//HintName: Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGeneric2ExtensionAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using System.Drawing;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Zomp.SyncMethodGenerator.IntegrationTests
+{
+    using Extensi.ons123;
+
+    partial class Extensions
+    {
+        public static void HasGeneric2Extension(object o)
+        {
+            var z = global::Extensi.ons123.MyExtensionClass.TryGetValue<global::System.Drawing.Point, global::System.Drawing.PointF>(o, out var _, out var _1);
+        }
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.UnwrapGenericExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGenericExtensionAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.UnwrapGenericExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGenericExtensionAsync.g.verified.cs
index 86fde87..1cb1e58 100644
--- a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.UnwrapGenericExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGenericExtensionAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.UnwrapGenericExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGenericExtensionAsync.g.verified.cs
@@ -1,13 +1,20 @@
-//HintName: Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGenericExtensionAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace Zomp.SyncMethodGenerator.IntegrationTests
-{
-    partial class Extensions
-    {
-        public static void HasGenericExtension(object o)
-        {
-            var z = global::Extensi.ons123.MyExtensionClass.TryGetValue<global::System.Drawing.Point>(o, out var item);
-        }
-    }
-}
+//HintName: Zomp.SyncMethodGenerator.IntegrationTests.Extensions.HasGenericExtensionAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using System.Drawing;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Zomp.SyncMethodGenerator.IntegrationTests
+{
+    using Extensi.ons123;
+
+    partial class Extensions
+    {
+        public static void HasGenericExtension(object o)
+        {
+            var z = global::Extensi.ons123.MyExtensionClass.TryGetValue<global::System.Drawing.Point>(o, out var item);
+        }
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/MemoryTests.NonPredefinedTypes#N1.Class.FillAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/MemoryTests.NonPredefinedTypes#N1.Class.FillAsync.g.verified.cs
index 450c3c8..6beaa27 100644
--- a/tests/Generator.Tests/Snapshots/MemoryTests.NonPredefinedTypes#N1.Class.FillAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/MemoryTests.NonPredefinedTypes#N1.Class.FillAsync.g.verified.cs
@@ -1,14 +1,18 @@
-//HintName: N1.Class.FillAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace N1
-{
-    partial class Class
-    {
-        void Fill(global::System.Span<global::N2.C1.C2.Accelerometer> accelerometers)
-        {
-            global::N2.C1.C2.Accelerometer a = new(1, 2, 3);
-            accelerometers[0] = a;
-        }
-    }
-}
+//HintName: N1.Class.FillAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using N2;
+using static N2.C1;
+
+namespace N1
+{
+    partial class Class
+    {
+        void Fill(global::System.Span<global::N2.C1.C2.Accelerometer> accelerometers)
+        {
+            global::N2.C1.C2.Accelerometer a = new(1, 2, 3);
+            accelerometers[0] = a;
+        }
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/SystemAsyncExtensionsTests.ConfiguredCancelableAsyncEnumerableExtensionUsingStatic#Test.Extensions.GetConfiguredAsyncEnumerator.g.verified.cs b/tests/Generator.Tests/Snapshots/SystemAsyncExtensionsTests.ConfiguredCancelableAsyncEnumerableExtensionUsingStatic#Test.Extensions.GetConfiguredAsyncEnumerator.g.verified.cs
index 468c0bc..d15b9fb 100644
--- a/tests/Generator.Tests/Snapshots/SystemAsyncExtensionsTests.ConfiguredCancelableAsyncEnumerableExtensionUsingStatic#Test.Extensions.GetConfiguredAsyncEnumerator.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/SystemAsyncExtensionsTests.ConfiguredCancelableAsyncEnumerableExtensionUsingStatic#Test.Extensions.GetConfiguredAsyncEnumerator.g.verified.cs
@@ -1,11 +1,14 @@
-//HintName: Test.Extensions.GetConfiguredAsyncEnumerator.g.cs
-// <auto-generated/>
-#nullable enable
-namespace Test;
-internal static partial class Extensions
-{
-    public static System.Collections.Generic.IEnumerator<int> GetConfiguredEnumerator(global::System.Collections.Generic.IEnumerable<int> enumerable)
-    {
-        return enumerable.GetEnumerator();
-    }
-}
+//HintName: Test.Extensions.GetConfiguredAsyncEnumerator.g.cs
+// <auto-generated/>
+#nullable enable
+
+using static System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable<int>;
+
+namespace Test;
+internal static partial class Extensions
+{
+    public static System.Collections.Generic.IEnumerator<int> GetConfiguredEnumerator(global::System.Collections.Generic.IEnumerable<int> enumerable)
+    {
+        return enumerable.GetEnumerator();
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/TypeTests.EnumPattern#g.verified.cs b/tests/Generator.Tests/Snapshots/TypeTests.EnumPattern#g.verified.cs
index 1d96052..3f3f147 100644
--- a/tests/Generator.Tests/Snapshots/TypeTests.EnumPattern#g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/TypeTests.EnumPattern#g.verified.cs
@@ -1,2 +1,14 @@
 //HintName: Test.Class.MethodAsync.g.cs
-_ = global::System.Data.ConnectionState.Closed is global::System.Data.ConnectionState.Closed;
+// <auto-generated/>
+#nullable enable
+
+using static System.Data.ConnectionState;
+
+namespace Test;
+partial class Class
+{
+    public void Method()
+    {
+        _ = global::System.Data.ConnectionState.Closed is global::System.Data.ConnectionState.Closed;
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#ReadAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#ReadAsync.g.verified.cs
index 6ef1c77..118b784 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#ReadAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.DropReturnsDocumentationWhenNothingIsReturned#ReadAsync.g.verified.cs
@@ -3,6 +3,5 @@
 /// Reads a value.
 /// </summary>
 /// <param name="input">Where to read from.</param>
-/// <returns>A <see cref="Task"/> that represents the asynchronous read.</returns>
 public void Read(global::System.IO.Stream input)
     => input.Flush();
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.GenericTypeInDeclarationPattern#M.B.DoSomethingAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.GenericTypeInDeclarationPattern#M.B.DoSomethingAsync.g.verified.cs
index cbd7124..ec8cd27 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.GenericTypeInDeclarationPattern#M.B.DoSomethingAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.GenericTypeInDeclarationPattern#M.B.DoSomethingAsync.g.verified.cs
@@ -3,6 +3,8 @@
 #nullable enable
 namespace M
 {
+    using N;
+
     public partial class B
     {
         public void DoSomething(object arg)
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.GenericTypeInTypeOfExpression#M.B.DoSomethingAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.GenericTypeInTypeOfExpression#M.B.DoSomethingAsync.g.verified.cs
index 1c8ff6b..9e3779c 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.GenericTypeInTypeOfExpression#M.B.DoSomethingAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.GenericTypeInTypeOfExpression#M.B.DoSomethingAsync.g.verified.cs
@@ -3,6 +3,8 @@
 #nullable enable
 namespace M
 {
+    using N;
+
     public partial class B
     {
         public void DoSomething()
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.HandleAttribute#ReadSomeBytesAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.HandleAttribute#ReadSomeBytesAsync.g.verified.cs
index 7a40f2c..108284f 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.HandleAttribute#ReadSomeBytesAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.HandleAttribute#ReadSomeBytesAsync.g.verified.cs
@@ -1,12 +1,15 @@
-//HintName: Test.Class.ReadSomeBytesAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace Test;
-public partial class Class
-{
-    public int ReadSomeBytes(global::System.IO.Stream stream)
-    {
-        var buffer = new byte[100];
-        return stream.Read(buffer, 0, 100);
-    }
-}
+//HintName: Test.Class.ReadSomeBytesAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace Test;
+public partial class Class
+{
+    public int ReadSomeBytes(global::System.IO.Stream stream)
+    {
+        var buffer = new byte[100];
+        return stream.Read(buffer, 0, 100);
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.KeepUsingsSoDocumentationCrefsResolve#SendAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.KeepUsingsSoDocumentationCrefsResolve#SendAsync.g.verified.cs
index 92f2ca0..d6d7e58 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.KeepUsingsSoDocumentationCrefsResolve#SendAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.KeepUsingsSoDocumentationCrefsResolve#SendAsync.g.verified.cs
@@ -1,8 +1,13 @@
 //HintName: Test.Class.SendAsync.g.cs
 // <auto-generated/>
 #nullable enable
+
+using System.Text;
+
 namespace Test
 {
+    using System.Net.Sockets;
+
     public partial class Class
     {
         /// <summary>
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.Preprocessor#WrappedAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.Preprocessor#WrappedAsync.g.verified.cs
index 4cbb8ab..7572de3 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.Preprocessor#WrappedAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.Preprocessor#WrappedAsync.g.verified.cs
@@ -1,11 +1,15 @@
-//HintName: Test.Class.WrappedAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace Test;
-public partial class Class
-{
-    /// <summary>
-    /// A summary
-    /// </summary>
-    public void Wrapped() { }
-}
+//HintName: Test.Class.WrappedAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Test;
+public partial class Class
+{
+    /// <summary>
+    /// A summary
+    /// </summary>
+    public void Wrapped() { }
+}
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.StaticUsings#N1.C1.MethodAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.StaticUsings#N1.C1.MethodAsync.g.verified.cs
index b0e977c..a1f40f5 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.StaticUsings#N1.C1.MethodAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.StaticUsings#N1.C1.MethodAsync.g.verified.cs
@@ -1,13 +1,16 @@
-//HintName: N1.C1.MethodAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace N1
-{
-    public partial class C1
-    {
-        public void Method()
-        {
-            _ = global::N2.C2.OtherConst;
-        }
-    }
-}
+//HintName: N1.C1.MethodAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using static N2.C2;
+
+namespace N1
+{
+    public partial class C1
+    {
+        public void Method()
+        {
+            _ = global::N2.C2.OtherConst;
+        }
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.OneParamsAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.OneParamsAsync.g.verified.cs
index 05d3421..87493f6 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.OneParamsAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.OneParamsAsync.g.verified.cs
@@ -1,10 +1,16 @@
-//HintName: Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.OneParamsAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace Zomp.SyncMethodGenerator.IntegrationTests
-{
-    partial class ExtensionMethods
-    {
-        public static void OneParams(object o, string s) => global::Extensi.ons123.MyExtensionClass.SomeMethod(o, s);
-    }
-}
+//HintName: Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.OneParamsAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Zomp.SyncMethodGenerator.IntegrationTests
+{
+    using Extensi.ons123;
+
+    partial class ExtensionMethods
+    {
+        public static void OneParams(object o, string s) => global::Extensi.ons123.MyExtensionClass.SomeMethod(o, s);
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.TwoParamsAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.TwoParamsAsync.g.verified.cs
index 0d91e8e..7f5f080 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.TwoParamsAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.TwoParamsAsync.g.verified.cs
@@ -1,10 +1,16 @@
-//HintName: Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.TwoParamsAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace Zomp.SyncMethodGenerator.IntegrationTests
-{
-    partial class ExtensionMethods
-    {
-        public static void TwoParams(object o, string s, int i) => global::Extensi.ons123.MyExtensionClass.SomeMethod(o, s, i);
-    }
-}
+//HintName: Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.TwoParamsAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Zomp.SyncMethodGenerator.IntegrationTests
+{
+    using Extensi.ons123;
+
+    partial class ExtensionMethods
+    {
+        public static void TwoParams(object o, string s, int i) => global::Extensi.ons123.MyExtensionClass.SomeMethod(o, s, i);
+    }
+}
diff --git a/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.ZeroParamsAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.ZeroParamsAsync.g.verified.cs
index 01feca1..ab68f68 100644
--- a/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.ZeroParamsAsync.g.verified.cs
+++ b/tests/Generator.Tests/Snapshots/UnitTests.UnwrapExtensionMethod#Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.ZeroParamsAsync.g.verified.cs
@@ -1,10 +1,16 @@
-//HintName: Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.ZeroParamsAsync.g.cs
-// <auto-generated/>
-#nullable enable
-namespace Zomp.SyncMethodGenerator.IntegrationTests
-{
-    partial class ExtensionMethods
-    {
-        public static void ZeroParams(object o) => global::Extensi.ons123.MyExtensionClass.SomeMethod(o);
-    }
-}
+//HintName: Zomp.SyncMethodGenerator.IntegrationTests.ExtensionMethods.ZeroParamsAsync.g.cs
+// <auto-generated/>
+#nullable enable
+
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Zomp.SyncMethodGenerator.IntegrationTests
+{
+    using Extensi.ons123;
+
+    partial class ExtensionMethods
+    {
+        public static void ZeroParams(object o) => global::Extensi.ons123.MyExtensionClass.SomeMethod(o);
+    }
+}