Tweaks to the '[ObservableProperty]' code fixer

Author: Sergio0694

src/CommunityToolkit.Mvvm.CodeFixers/UsePartialPropertyForObservablePropertyCodeFixer.cs

@@ -57,7 +57,9 @@ public sealed class UsePartialPropertyForObservablePropertyCodeFixer : CodeFixPr
     });
 
     /// <inheritdoc/>
-    public override ImmutableArray<string> FixableDiagnosticIds { get; } = ImmutableArray.Create(UseObservablePropertyOnPartialPropertyId);
+    public override ImmutableArray<string> FixableDiagnosticIds { get; } = ImmutableArray.Create(
+        UseObservablePropertyOnPartialPropertyId,
+        WinRTObservablePropertyOnFieldsIsNotAotCompatibleId);
 
     /// <inheritdoc/>
     public override FixAllProvider? GetFixAllProvider()
@@ -77,6 +79,14 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
             return;
         }
 
+        SemanticModel semanticModel = (await context.Document.GetSemanticModelAsync(context.CancellationToken).ConfigureAwait(false))!;
+
+        // If the language is not preview, we cannot apply this code fix (as it would generate invalid C# code)
+        if (!semanticModel.Compilation.IsLanguageVersionPreview())
+        {
+            return;
+        }
+
         // Retrieve the properties passed by the analyzer
         if (diagnostic.Properties[FieldReferenceForObservablePropertyFieldAnalyzer.FieldNameKey] is not string fieldName ||
             diagnostic.Properties[FieldReferenceForObservablePropertyFieldAnalyzer.PropertyNameKey] is not string propertyName)
@@ -101,7 +111,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
             context.RegisterCodeFix(
                 CodeAction.Create(
                     title: "Use a partial property",
-                    createChangedDocument: token => ConvertToPartialProperty(context.Document, root, fieldDeclaration, fieldName, propertyName, context.CancellationToken),
+                    createChangedDocument: token => ConvertToPartialProperty(context.Document, root, fieldDeclaration, semanticModel, fieldName, propertyName, context.CancellationToken),
                     equivalenceKey: "Use a partial property"),
                 diagnostic);
         }
@@ -113,6 +123,7 @@ public override async Task RegisterCodeFixesAsync(CodeFixContext context)
     /// <param name="document">The original document being fixed.</param>
     /// <param name="root">The original tree root belonging to the current document.</param>
     /// <param name="fieldDeclaration">The <see cref="FieldDeclarationSyntax"/> for the field being updated.</param>
+    /// <param name="semanticModel">The semantic model for <paramref name="document"/>.</param>
     /// <param name="fieldName">The name of the annotated field.</param>
     /// <param name="propertyName">The name of the generated property.</param>
     /// <param name="cancellationToken">The cancellation token for the operation.</param>
@@ -121,11 +132,12 @@ private static async Task<Document> ConvertToPartialProperty(
         Document document,
         SyntaxNode root,
         FieldDeclarationSyntax fieldDeclaration,
+        SemanticModel semanticModel,
         string fieldName,
         string propertyName,
         CancellationToken cancellationToken)
     {
-        SemanticModel semanticModel = (await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false))!;
+        await Task.CompletedTask;
 
         // Try to get all necessary type symbols to process the attributes
         if (!semanticModel.Compilation.TryBuildNamedTypeSymbolMap(MvvmToolkitAttributeNamesToFullyQualifiedNamesMap, out ImmutableDictionary<string, INamedTypeSymbol>? toolkitTypeSymbols) ||

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

@@ -41,8 +41,6 @@ public override void Initialize(AnalysisContext context)
                 return;
             }
 
-            bool isLanguageVersionPreview = context.Compilation.IsLanguageVersionPreview();
-
             context.RegisterSymbolAction(context =>
             {
                 // Ensure we do have a valid field
@@ -54,28 +52,14 @@ public override void Initialize(AnalysisContext context)
                 // Emit a diagnostic if the field is using the [ObservableProperty] attribute
                 if (fieldSymbol.TryGetAttributeWithType(observablePropertySymbol, out AttributeData? observablePropertyAttribute))
                 {
-                    // If the C# version is preview, we can include the necessary information to trigger the
-                    // code fixer. If that is not the case, we shouldn't do that, to avoid the code fixer
-                    // changing the code to invalid C# (as without the preview version, it wouldn't compile).
-                    if (isLanguageVersionPreview)
-                    {
-                        context.ReportDiagnostic(Diagnostic.Create(
-                            WinRTObservablePropertyOnFieldsIsNotAotCompatible,
-                            observablePropertyAttribute.GetLocation(),
-                            ImmutableDictionary.Create<string, string?>()
-                                .Add(FieldReferenceForObservablePropertyFieldAnalyzer.FieldNameKey, fieldSymbol.Name)
-                                .Add(FieldReferenceForObservablePropertyFieldAnalyzer.PropertyNameKey, ObservablePropertyGenerator.Execute.GetGeneratedPropertyName(fieldSymbol)),
-                            fieldSymbol.ContainingType,
-                            fieldSymbol.Name));
-                    }
-                    else
-                    {
-                        context.ReportDiagnostic(Diagnostic.Create(
-                            WinRTObservablePropertyOnFieldsIsNotAotCompatible,
-                            observablePropertyAttribute.GetLocation(),
-                            fieldSymbol.ContainingType,
-                            fieldSymbol.Name));
-                    }
+                    context.ReportDiagnostic(Diagnostic.Create(
+                        WinRTObservablePropertyOnFieldsIsNotAotCompatible,
+                        observablePropertyAttribute.GetLocation(),
+                        ImmutableDictionary.Create<string, string?>()
+                            .Add(FieldReferenceForObservablePropertyFieldAnalyzer.FieldNameKey, fieldSymbol.Name)
+                            .Add(FieldReferenceForObservablePropertyFieldAnalyzer.PropertyNameKey, ObservablePropertyGenerator.Execute.GetGeneratedPropertyName(fieldSymbol)),
+                        fieldSymbol.ContainingType,
+                        fieldSymbol.Name));
                 }
             }, SymbolKind.Field);
         });