Add repro for #5457

analyzers/src/SonarAnalyzer.CSharp/Rules/ExtensionMethodShouldBeInSeparateNamespace.cs

@@ -32,11 +32,9 @@ namespace SonarAnalyzer.Rules.CSharp
     public sealed class ExtensionMethodShouldBeInSeparateNamespace : SonarDiagnosticAnalyzer
     {
         private const string DiagnosticId = "S4226";
-        private const string MessageFormat = "Either move this extension to another namespace or move the method " +
-            "inside the class itself.";
+        private const string MessageFormat = "Either move this extension to another namespace or move the method inside the class itself.";
 
-        private static readonly DiagnosticDescriptor Rule =
-            DiagnosticDescriptorBuilder.GetDescriptor(DiagnosticId, MessageFormat, RspecStrings.ResourceManager);
+        private static readonly DiagnosticDescriptor Rule = DiagnosticDescriptorBuilder.GetDescriptor(DiagnosticId, MessageFormat, RspecStrings.ResourceManager);
         public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(Rule);
 
         protected override void Initialize(SonarAnalysisContext context) =>
@@ -46,9 +44,7 @@ protected override void Initialize(SonarAnalysisContext context) =>
                     var methodDeclaration = (MethodDeclarationSyntax)c.Node;
 
                     if (methodDeclaration.IsExtensionMethod()
-                        && c.SemanticModel.GetDeclaredSymbol(methodDeclaration) is { } methodSymbol
-                        && methodSymbol.IsExtensionMethod
-                        && methodSymbol.Parameters.Length > 0
+                        && c.SemanticModel.GetDeclaredSymbol(methodDeclaration) is { IsExtensionMethod: true, Parameters: { Length: > 0 } } methodSymbol
                         && methodSymbol.Parameters[0].Type.Kind != SymbolKind.ErrorType
                         && methodSymbol.Parameters[0].Type.IsClass()
                         && methodSymbol.ContainingNamespace.Equals(methodSymbol.Parameters[0].Type.ContainingNamespace))

analyzers/tests/SonarAnalyzer.UnitTest/Rules/ExtensionMethodShouldBeInSeparateNamespaceTest.cs

@@ -27,19 +27,29 @@ namespace SonarAnalyzer.UnitTest.Rules
     [TestClass]
     public class ExtensionMethodShouldBeInSeparateNamespaceTest
     {
+        private readonly VerifierBuilder builder = new VerifierBuilder<ExtensionMethodShouldBeInSeparateNamespace>();
+
         [TestMethod]
         public void ExtensionMethodShouldBeInSeparateNamespace() =>
-            OldVerifier.VerifyAnalyzer(@"TestCases\ExtensionMethodShouldBeInSeparateNamespace.cs", new ExtensionMethodShouldBeInSeparateNamespace());
+            builder
+                .AddPaths("ExtensionMethodShouldBeInSeparateNamespace.cs", "ExtensionMethodShouldBeInSeparateNamespace.GeneratedCode.cs")
+                .Verify();
 
 #if NET
+
         [TestMethod]
         public void ExtensionMethodShouldBeInSeparateNamespace_CSharp9() =>
-            OldVerifier.VerifyAnalyzerFromCSharp9Console(@"TestCases\ExtensionMethodShouldBeInSeparateNamespace.CSharp9.cs", new ExtensionMethodShouldBeInSeparateNamespace());
+            builder.AddPaths("ExtensionMethodShouldBeInSeparateNamespace.CSharp9.cs").WithTopLevelStatements().Verify();
 
         [TestMethod]
         public void ExtensionMethodShouldBeInSeparateNamespace_CSharp10() =>
-            OldVerifier.VerifyAnalyzerFromCSharp10Library(@"TestCases\ExtensionMethodShouldBeInSeparateNamespace.CSharp10.cs", new ExtensionMethodShouldBeInSeparateNamespace());
+            builder
+                .AddPaths("ExtensionMethodShouldBeInSeparateNamespace.CSharp10.cs")
+                .WithConcurrentAnalysis(false)
+                .WithOptions(ParseOptionsHelper.FromCSharp10)
+                .Verify();
 
 #endif
+
     }
 }

analyzers/tests/SonarAnalyzer.UnitTest/TestCases/ExtensionMethodShouldBeInSeparateNamespace.GeneratedCode.cs

@@ -0,0 +1,4 @@
+[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.8.3928.0")]
+public abstract partial class GenClass
+{
+}

analyzers/tests/SonarAnalyzer.UnitTest/TestCases/ExtensionMethodShouldBeInSeparateNamespace.cs

@@ -106,3 +106,8 @@ public static T FooGeneric<T>(this T foo) // Compliant
     }
 
 }
+
+internal static class GenClassExtensions
+{
+    public static void SetSyncLaterError(this GenClass foo) { } // Noncompliant - FP, see: https://github.com/SonarSource/sonar-dotnet/issues/5457
+}