From bf4870a0c0dbcce9dd91087c455af1717af7fbf9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Luthi?= <cedric.luthi@gmail.com>
Date: Fri, 4 Sep 2026 13:48:45 +0200
Subject: [PATCH 1/2] Add test for ToListAsync() on 'IQueryable<T>'

Currently fails with this compilation error:
> No overload for method 'ToList' takes 1 arguments
---
 tests/Generator.Tests/ExtensionMethodTests.cs | 22 +++++++++++++++++++
 ...3d48c88.QueryableToListAsync.g.verified.cs | 21 ++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 tests/Generator.Tests/Snapshots/ExtensionMethodTests.EntityFrameworkQueryableToListAsync#Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQueryabl_b3d48c88.QueryableToListAsync.g.verified.cs

diff --git a/tests/Generator.Tests/ExtensionMethodTests.cs b/tests/Generator.Tests/ExtensionMethodTests.cs
index 1ff1d3c..6311e26 100644
--- a/tests/Generator.Tests/ExtensionMethodTests.cs
+++ b/tests/Generator.Tests/ExtensionMethodTests.cs
@@ -144,6 +144,28 @@ public async Task<int> QueryableExtensionAsync(DbContext dbContext, Cancellation
         }
     }
 }
+""".Verify(sourceType: SourceType.Full);
+
+    [Fact]
+    public Task EntityFrameworkQueryableToListAsync() => """
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Zomp.SyncMethodGenerator.IntegrationTests
+{
+    using Microsoft.EntityFrameworkCore;
+
+    public partial class EntityFrameworkQueryableExtensions
+    {
+        [Zomp.SyncMethodGenerator.CreateSyncVersion]
+        public async Task<int> QueryableToListAsync(DbContext dbContext, CancellationToken cancellationToken)
+        {
+            var dbSet = dbContext.Set<object>();
+            var result = await dbSet.ToListAsync(cancellationToken);
+            return result.Count;
+        }
+    }
+}
 """.Verify(sourceType: SourceType.Full);
 #endif
 
diff --git a/tests/Generator.Tests/Snapshots/ExtensionMethodTests.EntityFrameworkQueryableToListAsync#Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQueryabl_b3d48c88.QueryableToListAsync.g.verified.cs b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.EntityFrameworkQueryableToListAsync#Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQueryabl_b3d48c88.QueryableToListAsync.g.verified.cs
new file mode 100644
index 0000000..dbf5ba7
--- /dev/null
+++ b/tests/Generator.Tests/Snapshots/ExtensionMethodTests.EntityFrameworkQueryableToListAsync#Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQueryabl_b3d48c88.QueryableToListAsync.g.verified.cs
@@ -0,0 +1,21 @@
+//HintName: Zomp.SyncMethodGenerator.IntegrationTests.EntityFrameworkQueryabl_b3d48c88.QueryableToListAsync.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 QueryableToList(global::Microsoft.EntityFrameworkCore.DbContext dbContext)
+        {
+            var dbSet = dbContext.Set<object>();
+            var result = global::System.Linq.Enumerable.ToList(dbSet);
+            return result.Count;
+        }
+    }
+}

From 290415162d27fbed17e8fa756142d4baa01f793c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Luthi?= <cedric.luthi@gmail.com>
Date: Mon, 7 Sep 2026 11:27:32 +0200
Subject: [PATCH 2/2] Fix LINQ async to sync translation for extensions

After #108, #110 and #123 let's hope it's the definitive fix.
---
 .../AsyncToSyncRewriter.cs                    | 30 ++++++++++---------
 .../Helpers/CompilationExtensions.cs          | 22 ++++++++++++++
 2 files changed, 38 insertions(+), 14 deletions(-)
 create mode 100644 src/Zomp.SyncMethodGenerator/Helpers/CompilationExtensions.cs

diff --git a/src/Zomp.SyncMethodGenerator/AsyncToSyncRewriter.cs b/src/Zomp.SyncMethodGenerator/AsyncToSyncRewriter.cs
index f975add..b8a0135 100644
--- a/src/Zomp.SyncMethodGenerator/AsyncToSyncRewriter.cs
+++ b/src/Zomp.SyncMethodGenerator/AsyncToSyncRewriter.cs
@@ -1516,7 +1516,6 @@ private static string MakeType(ISymbol symbol)
         => symbol switch
         {
             INamedTypeSymbol { Name: "AsyncEnumerable" } => Global("System.Linq.Enumerable"),
-            INamedTypeSymbol { Name: "EntityFrameworkQueryableExtensions" } => Global("System.Linq.Queryable"),
             INamedTypeSymbol => symbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat),
             _ => symbol.Name,
         };
@@ -2067,19 +2066,22 @@ private InvocationExpressionSyntax UnwrapExtension(InvocationExpressionSyntax ie
         var newName = reducedFrom.Name;
         newName = changeMemoryToSpan ? ReplaceWithSpan(reducedFrom) : RemoveAsync(newName);
 
-        var membersWithNewNameInContainingType = semanticModel.Compilation.References
-            .Select(semanticModel.Compilation.GetAssemblyOrModuleSymbol)
-            .Append(semanticModel.Compilation.Assembly)
-            .OfType<IAssemblySymbol>()
-            .Select(assemblySymbol => assemblySymbol.GetTypeByMetadataName(containingType.ToString()))
-            .OfType<INamedTypeSymbol>()
-            .SelectMany(symbol => symbol.GetMembers(newName));
-
-        // When the method is an AsyncEnumerable extension it must be converted to the corresponding Enumerable extension
-        // regardless of the containing type featuring members with compatible names
-        var fullyQualifiedName = !containingType.Name.Equals("AsyncEnumerable", StringComparison.Ordinal) && membersWithNewNameInContainingType.Any()
-            ? $"{containingType.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat)}.{newName}"
-            : $"{MakeType(containingType)}.{newName}";
+        var (enumerableMembers, queryableMembers) = semanticModel.Compilation.GetLinqMembers();
+
+        var fullyQualifiedName = $"{MakeType(containingType)}.{newName}";
+
+        // Supports EntityFrameworkQueryableExtensions and potentially other queryable extensions
+        if (containingType.Name.EndsWith("QueryableExtensions", StringComparison.OrdinalIgnoreCase))
+        {
+            if (queryableMembers.Contains(newName))
+            {
+                fullyQualifiedName = $"{Global("System.Linq.Queryable")}.{newName}";
+            }
+            else if (enumerableMembers.Contains(newName))
+            {
+                fullyQualifiedName = $"{Global("System.Linq.Enumerable")}.{newName}";
+            }
+        }
 
         var es = (ies.Expression switch
         {
diff --git a/src/Zomp.SyncMethodGenerator/Helpers/CompilationExtensions.cs b/src/Zomp.SyncMethodGenerator/Helpers/CompilationExtensions.cs
new file mode 100644
index 0000000..ed8dcc2
--- /dev/null
+++ b/src/Zomp.SyncMethodGenerator/Helpers/CompilationExtensions.cs
@@ -0,0 +1,22 @@
+namespace Zomp.SyncMethodGenerator.Helpers;
+
+internal static class CompilationExtensions
+{
+    public static (ISet<string> EnumerableMembers, ISet<string> QueryableMembers) GetLinqMembers(this Compilation compilation)
+    {
+        INamedTypeSymbol? linqEnumerable = null;
+        INamedTypeSymbol? linqQueryable = null;
+        foreach (var reference in compilation.References)
+        {
+            var assemblySymbol = compilation.GetAssemblyOrModuleSymbol(reference) as IAssemblySymbol;
+            linqEnumerable ??= assemblySymbol?.GetTypeByMetadataName("System.Linq.Enumerable");
+            linqQueryable ??= assemblySymbol?.GetTypeByMetadataName("System.Linq.Queryable");
+            if (linqEnumerable != null && linqQueryable != null)
+            {
+                break;
+            }
+        }
+
+        return (new HashSet<string>(linqEnumerable?.MemberNames ?? []), new HashSet<string>(linqQueryable?.MemberNames ?? []));
+    }
+}