Support nested blocks in semi-auto property analyzer, add tests

src/CommunityToolkit.Mvvm.SourceGenerators/Diagnostics/Analyzers/UseObservablePropertyOnSemiAutoPropertyAnalyzer.cs

@@ -148,7 +148,16 @@ public override void Initialize(AnalysisContext context)
                         // We expect a top-level block operation, that immediately returns an expression
                         if (context.OperationBlocks is not [IBlockOperation { Operations: [IReturnOperation returnOperation] }])
                         {
-                            return;
+                            // Special case for nested blocks (e.g. for code generated by some other tooling)
+                            if (context.OperationBlocks is [IBlockOperation { Operations: [IBlockOperation { Operations: [IReturnOperation nestedReturnOperation] }] }])
+                            {
+                                returnOperation = nestedReturnOperation;
+                            }
+                            else
+                            {
+                                // Invalid 'get' accessor structure, we have to stop here
+                                return;
+                            }
                         }
 
                         // Next, we expect the return to produce a field reference

tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn4120.UnitTests/Test_UseObservablePropertyOnSemiAutoPropertyCodeFixer.cs

@@ -74,6 +74,123 @@ public partial class SampleViewModel : ObservableObject
         await test.RunAsync();
     }
 
+    [TestMethod]
+    public async Task SimplePropertyWithBlockAccessorSyntax()
+    {
+        string original = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp;
+
+            public class SampleViewModel : ObservableObject
+            {
+                public string Name
+                {
+                    get
+                    {
+                        return field;
+                    }
+                    set
+                    {
+                        SetProperty(ref field, value);
+                    }
+                }
+            }
+            """;
+
+        string @fixed = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp;
+
+            public partial class SampleViewModel : ObservableObject
+            {
+                [ObservableProperty]
+                public partial string Name { get; set; }
+            }
+            """;
+
+        CSharpCodeFixTest test = new(LanguageVersion.Preview)
+        {
+            TestCode = original,
+            FixedCode = @fixed,
+            ReferenceAssemblies = ReferenceAssemblies.Net.Net80,
+        };
+
+        test.TestState.AdditionalReferences.Add(typeof(ObservableObject).Assembly);
+        test.ExpectedDiagnostics.AddRange(new[]
+        {
+            // /0/Test0.cs(7,19): info MVVMTK0056: The semi-auto property MyApp.SampleViewModel.Name can be converted to a partial property using [ObservableProperty], which is recommended (doing so makes the code less verbose and results in more optimized code)
+            CSharpCodeFixVerifier.Diagnostic().WithSpan(7, 19, 7, 23).WithArguments("MyApp.SampleViewModel", "Name"),
+        });
+
+        test.FixedState.ExpectedDiagnostics.AddRange(new[]
+        {
+            // /0/Test0.cs(8,27): error CS9248: Partial property 'SampleViewModel.Name' must have an implementation part.
+            DiagnosticResult.CompilerError("CS9248").WithSpan(8, 27, 8, 31).WithArguments("MyApp.SampleViewModel.Name"),
+        });
+
+        await test.RunAsync();
+    }
+
+    [TestMethod]
+    public async Task SimplePropertyWithNestedBlockSyntax()
+    {
+        string original = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp;
+
+            public class SampleViewModel : ObservableObject
+            {
+                public string Name
+                {
+                    get
+                    {
+                        {
+                            return field;
+                        }
+                    }
+                    set => SetProperty(ref field, value);
+                }
+            }
+            """;
+
+        string @fixed = """
+            using CommunityToolkit.Mvvm.ComponentModel;
+
+            namespace MyApp;
+
+            public partial class SampleViewModel : ObservableObject
+            {
+                [ObservableProperty]
+                public partial string Name { get; set; }
+            }
+            """;
+
+        CSharpCodeFixTest test = new(LanguageVersion.Preview)
+        {
+            TestCode = original,
+            FixedCode = @fixed,
+            ReferenceAssemblies = ReferenceAssemblies.Net.Net80,
+        };
+
+        test.TestState.AdditionalReferences.Add(typeof(ObservableObject).Assembly);
+        test.ExpectedDiagnostics.AddRange(new[]
+        {
+            // /0/Test0.cs(7,19): info MVVMTK0056: The semi-auto property MyApp.SampleViewModel.Name can be converted to a partial property using [ObservableProperty], which is recommended (doing so makes the code less verbose and results in more optimized code)
+            CSharpCodeFixVerifier.Diagnostic().WithSpan(7, 19, 7, 23).WithArguments("MyApp.SampleViewModel", "Name"),
+        });
+
+        test.FixedState.ExpectedDiagnostics.AddRange(new[]
+        {
+            // /0/Test0.cs(8,27): error CS9248: Partial property 'SampleViewModel.Name' must have an implementation part.
+            DiagnosticResult.CompilerError("CS9248").WithSpan(8, 27, 8, 31).WithArguments("MyApp.SampleViewModel.Name"),
+        });
+
+        await test.RunAsync();
+    }
+
     [TestMethod]
     public async Task SimpleProperty_WithSemicolonTokenGetAccessor()
     {