Fix: source generation duplicate fix for partial classes

TUnit.Core.SourceGenerator/Generators/DataSourceHelpersGenerator.cs

@@ -17,9 +17,11 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             .CreateSyntaxProvider(
                 predicate: static (s, _) => s is ClassDeclarationSyntax,
                 transform: static (ctx, _) => GetTypeWithDataSourceProperties(ctx))
-            .Where(static t => t is not null);
+            .Where(static t => t is not null)
+            .Collect()
+            .SelectMany((types, _) => types.DistinctBy(t => t!.Value.TypeSymbol, SymbolEqualityComparer.Default));
 
-        // Generate individual files for each type instead of collecting them all
+        // Generate individual files for each unique type
         context.RegisterSourceOutput(typesWithDataSourceProperties, (spc, type) => { if (type != null) GenerateIndividualDataSourceHelper(spc, type); });
     }
 

TUnit.Core.SourceGenerator/Generators/PropertyInjectionSourceGenerator.cs

@@ -16,9 +16,11 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
                 predicate: (node, _) => IsClassWithDataSourceProperties(node),
                 transform: (ctx, _) => GetClassWithDataSourceProperties(ctx))
             .Where(x => x != null)
-            .Select((x, _) => x!);
+            .Select((x, _) => x!)
+            .Collect()
+            .SelectMany((classes, _) => classes.DistinctBy(c => c.ClassSymbol, SymbolEqualityComparer.Default));
 
-        // Generate individual files for each class instead of collecting them all
+        // Generate individual files for each unique class
         context.RegisterSourceOutput(classesWithPropertyInjection, GenerateIndividualPropertyInjectionSource);
     }
 
@@ -89,6 +91,12 @@ private static bool IsClassWithDataSourceProperties(SyntaxNode node)
             }
         }
 
+        // Only return if there are actually properties with data sources
+        if (propertiesWithDataSources.Count == 0)
+        {
+            return null;
+        }
+
         return new ClassWithDataSourceProperties
         {
             ClassSymbol = typeSymbol,

TUnit.TestProject/Bugs/3231/DataClass.cs

@@ -0,0 +1,6 @@
+namespace TUnit.TestProject.Bugs._3231;
+
+public class DataClass
+{
+    public string Value { get; set; } = "Test Data";
+}

TUnit.TestProject/Bugs/3231/TestsPart1.cs

@@ -0,0 +1,13 @@
+using TUnit.TestProject.Attributes;
+
+namespace TUnit.TestProject.Bugs._3231;
+
+[EngineTest(ExpectedResult.Pass)]
+public partial class Tests
+{
+    [Test]
+    public void Basic()
+    {
+        Console.WriteLine($"This is a basic test with data: {DataClass.Value}");
+    }
+}

TUnit.TestProject/Bugs/3231/TestsPart2.cs

@@ -0,0 +1,7 @@
+namespace TUnit.TestProject.Bugs._3231;
+
+public partial class Tests
+{
+    [ClassDataSource<DataClass>(Shared = SharedType.PerTestSession)]
+    public required DataClass DataClass { get; init; }
+}