protected override async Task RegisterCodeFixesAsync(DocumentEditorCodeFixContext context) { var syntaxRoot = await context.Document.GetSyntaxRootAsync(context.CancellationToken) .ConfigureAwait(false); var semanticModel = await context.Document.GetSemanticModelAsync(context.CancellationToken) .ConfigureAwait(false); foreach (var diagnostic in context.Diagnostics) { if (syntaxRoot.TryFindNodeOrAncestor(diagnostic, out ExpressionStatementSyntax? onPropertyChangedStatement) && onPropertyChangedStatement.TryFirstAncestor(out AccessorDeclarationSyntax? setter) && setter.IsKind(SyntaxKind.SetAccessorDeclaration) && setter.Body is { } body) { if (Setter.TryFindSingleAssignment(setter, out var assignment) && assignment.Parent is ExpressionStatementSyntax assignmentStatement && body.Statements.IndexOf(assignmentStatement) == 0) { if (semanticModel.TryGetSymbol(assignment.Left, CancellationToken.None, out var assignedSymbol) && assignedSymbol.Kind == SymbolKind.Field && semanticModel.TryGetSymbol(setter, context.CancellationToken, out IMethodSymbol? setterSymbol) && TrySet.TryFind(setterSymbol.ContainingType, semanticModel, context.CancellationToken, out var trySetMethod) && TrySet.CanCreateInvocation(trySetMethod, out _) && setter.TryFirstAncestor(out PropertyDeclarationSyntax? property)) { if (setter.Body.Statements.Count == 2) { context.RegisterCodeFix( trySetMethod.DisplaySignature(), async(editor, cancellationToken) => { var trySet = await editor.TrySetInvocationAsync(trySetMethod, assignment.Left, assignment.Right, property, cancellationToken) .ConfigureAwait(false); _ = editor.ReplaceNode( setter, x => x.AsExpressionBody(trySet)); }, trySetMethod.MetadataName, diagnostic); } } context.RegisterCodeFix( "Check that value is different before notifying.", (editor, cancellationToken) => editor.InsertBefore( assignmentStatement, InpcFactory.IfReturn( InpcFactory.Equals( assignment.Right, assignment.Left, editor.SemanticModel, cancellationToken))), nameof(CheckIfDifferentBeforeNotifyFix), diagnostic); }
protected override async Task RegisterCodeFixesAsync(DocumentEditorCodeFixContext context) { var syntaxRoot = await context.Document.GetSyntaxRootAsync(context.CancellationToken) .ConfigureAwait(false); var semanticModel = await context.Document.GetSemanticModelAsync(context.CancellationToken) .ConfigureAwait(false); foreach (var diagnostic in context.Diagnostics) { if (syntaxRoot.TryFindNodeOrAncestor(diagnostic, out PropertyDeclarationSyntax? propertyDeclaration) && propertyDeclaration.Parent is ClassDeclarationSyntax classDeclarationSyntax && semanticModel.TryGetSymbol(classDeclarationSyntax, context.CancellationToken, out var type)) { if (TrySet.TryFind(type, semanticModel, context.CancellationToken, out var trySetMethod) && TrySet.CanCreateInvocation(trySetMethod, out _)) { if (Property.IsMutableAutoProperty(propertyDeclaration, out var getter, out var setter)) { context.RegisterCodeFix( trySetMethod.DisplaySignature(), (editor, cancellationToken) => TrySet(editor, cancellationToken), trySetMethod.MetadataName, diagnostic); async Task TrySet(DocumentEditor editor, CancellationToken cancellationToken) { var fieldAccess = await editor.AddBackingFieldAsync(propertyDeclaration, cancellationToken) .ConfigureAwait(false); var trySet = await editor.TrySetInvocationAsync(trySetMethod, fieldAccess, InpcFactory.Value, propertyDeclaration, cancellationToken) .ConfigureAwait(false); _ = editor.ReplaceNode( getter, x => x.AsExpressionBody(fieldAccess)) .ReplaceNode( setter, x => x.AsExpressionBody(trySet)); if (propertyDeclaration.Initializer != null) { editor.ReplaceNode( propertyDeclaration, (node, g) => ((PropertyDeclarationSyntax)node).WithoutInitializer()); } _ = editor.FormatNode(propertyDeclaration); } } else if (IsSimpleAssignmentOnly(propertyDeclaration, out _, out var assignment)) { context.RegisterCodeFix( trySetMethod.DisplaySignature(), async(editor, cancellationToken) => { var trySet = await editor.TrySetInvocationAsync(trySetMethod, assignment.Left, assignment.Right, propertyDeclaration, cancellationToken) .ConfigureAwait(false); _ = editor.ReplaceNode( assignment, x => trySet); }, trySetMethod.MetadataName, diagnostic); } } if (OnPropertyChanged.TryFind(type, semanticModel, context.CancellationToken, out var invoker) && invoker.Parameters.TrySingle(out var parameter) && parameter.Type.IsEither(KnownSymbol.String, KnownSymbol.PropertyChangedEventArgs)) { if (Property.IsMutableAutoProperty(propertyDeclaration, out var getter, out var setter) && semanticModel.TryGetSymbol(propertyDeclaration, context.CancellationToken, out var property)) { context.RegisterCodeFix( NotifyWhenValueChanges, (editor, cancellationToken) => NotifyWhenValueChangesAsync(editor, cancellationToken), nameof(NotifyWhenValueChangesAsync), diagnostic); async Task NotifyWhenValueChangesAsync(DocumentEditor editor, CancellationToken cancellationToken) { var backingField = await editor.AddBackingFieldAsync(propertyDeclaration, cancellationToken) .ConfigureAwait(false); var onPropertyChanged = await editor.OnPropertyChangedInvocationStatementAsync(invoker, propertyDeclaration, cancellationToken) .ConfigureAwait(false); _ = editor.ReplaceNode( getter, x => x.AsExpressionBody(backingField) .WithTrailingLineFeed()); _ = editor.ReplaceNode( setter, x => x.AsBlockBody( InpcFactory.IfReturn( InpcFactory.Equals(property.Type, InpcFactory.Value, backingField, editor.SemanticModel)), SyntaxFactory.ExpressionStatement(SyntaxFactory.AssignmentExpression(SyntaxKind.SimpleAssignmentExpression, backingField, InpcFactory.Value)), onPropertyChanged)); if (propertyDeclaration.Initializer != null) { _ = editor.ReplaceNode( propertyDeclaration, x => x.WithoutInitializer()); } _ = editor.FormatNode(propertyDeclaration); } }