public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsEnabled(CodeFixIdentifiers.ChangeMethodReturnType))
            {
                return;
            }

            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out SyntaxNode node, predicate: f => f.IsKind(SyntaxKind.MethodDeclaration, SyntaxKind.LocalFunctionStatement)))
            {
                return;
            }

            Diagnostic diagnostic = context.Diagnostics[0];

            SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

            var methodSymbol = (IMethodSymbol)semanticModel.GetDeclaredSymbol(node, context.CancellationToken);

            Debug.Assert(methodSymbol != null, node.Kind().ToString());

            ITypeSymbol typeSymbol = methodSymbol.ReturnType;

            if (typeSymbol.IsErrorType())
            {
                return;
            }

            (bool containsReturnAwait, bool containsAwaitStatement) = AnalyzeAwaitExpressions(node);

            Debug.Assert(containsAwaitStatement || containsReturnAwait, node.ToString());

            if (containsAwaitStatement)
            {
                INamedTypeSymbol taskSymbol = semanticModel.GetTypeByMetadataName("System.Threading.Tasks.Task");

                CodeFixRegistrator.ChangeTypeOrReturnType(context, diagnostic, node, taskSymbol, semanticModel, "Task");
            }

            if (containsReturnAwait)
            {
                typeSymbol = semanticModel.GetTypeByMetadataName("System.Threading.Tasks.Task`1").Construct(typeSymbol);

                CodeFixRegistrator.ChangeTypeOrReturnType(context, diagnostic, node, typeSymbol, semanticModel, "TaskOfT");
            }
        }
Пример #2
0
        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out MemberDeclarationSyntax memberDeclaration))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.MissingXmlCommentForPubliclyVisibleTypeOrMember:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddDocumentationComment))
                    {
                        break;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        "Add documentation comment",
                        cancellationToken => AddDocumentationCommentRefactoring.RefactorAsync(context.Document, memberDeclaration, false, cancellationToken),
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);

                    CodeAction codeAction2 = CodeAction.Create(
                        "Add documentation comment (copy from base if available)",
                        cancellationToken => AddDocumentationCommentRefactoring.RefactorAsync(context.Document, memberDeclaration, true, cancellationToken),
                        GetEquivalenceKey(diagnostic, "CopyFromBaseIfAvailable"));

                    context.RegisterCodeFix(codeAction2, diagnostic);
                    break;
                }

                case CompilerDiagnosticIdentifiers.MethodReturnTypeMustMatchOverriddenMethodReturnType:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeMethodReturnType))
                    {
                        break;
                    }

                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    var methodSymbol = (IMethodSymbol)semanticModel.GetDeclaredSymbol(memberDeclaration, context.CancellationToken);

                    ITypeSymbol typeSymbol = methodSymbol.OverriddenMethod.ReturnType;

                    CodeFixRegistrator.ChangeTypeOrReturnType(context, diagnostic, memberDeclaration, typeSymbol, semanticModel);

                    break;
                }

                case CompilerDiagnosticIdentifiers.PartialMethodsMustHaveVoidReturnType:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeMethodReturnType))
                    {
                        break;
                    }

                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    var methodDeclaration = (MethodDeclarationSyntax)memberDeclaration;

                    MethodDeclarationSyntax otherPart = semanticModel.GetOtherPart(methodDeclaration, context.CancellationToken);

                    if (otherPart == null)
                    {
                        break;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        "Change return type to 'void'",
                        cancellationToken =>
                        {
                            return(context.Document.Solution().ReplaceNodesAsync(
                                       new MethodDeclarationSyntax[] { methodDeclaration, otherPart },
                                       (node, _) => node.WithReturnType(CSharpFactory.VoidType().WithTriviaFrom(node.ReturnType)),
                                       cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);
                    break;
                }

                case CompilerDiagnosticIdentifiers.MemberTypeMustMatchOverriddenMemberType:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.MemberTypeMustMatchOverriddenMemberType))
                    {
                        break;
                    }

                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    ITypeSymbol typeSymbol = null;

                    switch (memberDeclaration.Kind())
                    {
                    case SyntaxKind.PropertyDeclaration:
                    case SyntaxKind.IndexerDeclaration:
                    {
                        var propertySymbol = (IPropertySymbol)semanticModel.GetDeclaredSymbol(memberDeclaration, context.CancellationToken);

                        typeSymbol = propertySymbol.OverriddenProperty.Type;
                        break;
                    }

                    case SyntaxKind.EventDeclaration:
                    {
                        var eventSymbol = (IEventSymbol)semanticModel.GetDeclaredSymbol(memberDeclaration, context.CancellationToken);

                        typeSymbol = eventSymbol.OverriddenEvent.Type;
                        break;
                    }

                    case SyntaxKind.EventFieldDeclaration:
                    {
                        VariableDeclaratorSyntax declarator = ((EventFieldDeclarationSyntax)memberDeclaration).Declaration.Variables[0];

                        var eventSymbol = (IEventSymbol)semanticModel.GetDeclaredSymbol(declarator, context.CancellationToken);

                        typeSymbol = eventSymbol.OverriddenEvent.Type;
                        break;
                    }
                    }

                    CodeFixRegistrator.ChangeTypeOrReturnType(context, diagnostic, memberDeclaration, typeSymbol, semanticModel);

                    break;
                }

                case CompilerDiagnosticIdentifiers.MissingPartialModifier:
                case CompilerDiagnosticIdentifiers.PartialMethodMustBeDeclaredInPartialClassOrPartialStruct:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddPartialModifier))
                    {
                        break;
                    }

                    SyntaxNode node = null;

                    switch (memberDeclaration.Kind())
                    {
                    case SyntaxKind.MethodDeclaration:
                    {
                        if (memberDeclaration.IsParentKind(SyntaxKind.ClassDeclaration, SyntaxKind.StructDeclaration))
                        {
                            node = memberDeclaration.Parent;
                        }

                        break;
                    }

                    case SyntaxKind.ClassDeclaration:
                    case SyntaxKind.StructDeclaration:
                    case SyntaxKind.InterfaceDeclaration:
                    case SyntaxKind.RecordDeclaration:
                    {
                        node = memberDeclaration;
                        break;
                    }
                    }

                    Debug.Assert(node != null, memberDeclaration.ToString());

                    if (node == null)
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, node, SyntaxKind.PartialKeyword, title: $"Make {CSharpFacts.GetTitle(node)} partial");
                    break;
                }

                case CompilerDiagnosticIdentifiers.MemberIsAbstractButItIsContainedInNonAbstractClass:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.MakeContainingClassAbstract))
                    {
                        break;
                    }

                    if (!memberDeclaration.IsParentKind(SyntaxKind.ClassDeclaration))
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.AddModifier(
                        context,
                        diagnostic,
                        memberDeclaration.Parent,
                        SyntaxKind.AbstractKeyword,
                        title: "Make containing class abstract");

                    break;
                }

                case CompilerDiagnosticIdentifiers.StaticConstructorMustBeParameterless:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveParametersFromStaticConstructor))
                    {
                        break;
                    }

                    var constructorDeclaration = (ConstructorDeclarationSyntax)memberDeclaration;

                    CodeAction codeAction = CodeAction.Create(
                        "Remove parameters",
                        cancellationToken =>
                        {
                            ParameterListSyntax parameterList = constructorDeclaration.ParameterList;

                            ParameterListSyntax newParameterList = parameterList
                                                                   .WithParameters(default(SeparatedSyntaxList <ParameterSyntax>))
                                                                   .WithOpenParenToken(parameterList.OpenParenToken.WithoutTrailingTrivia())
                                                                   .WithCloseParenToken(parameterList.CloseParenToken.WithoutLeadingTrivia());

                            ConstructorDeclarationSyntax newNode = constructorDeclaration.WithParameterList(newParameterList);

                            return(context.Document.ReplaceNodeAsync(constructorDeclaration, newNode, cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);
                    break;
                }

                case CompilerDiagnosticIdentifiers.ExplicitInterfaceDeclarationCanOnlyBeDeclaredInClassOrStruct:
                case CompilerDiagnosticIdentifiers.InterfacesCannotContainFields:
                case CompilerDiagnosticIdentifiers.InterfacesCannotContainOperators:
                case CompilerDiagnosticIdentifiers.InterfacesCannotDeclareTypes:
                case CompilerDiagnosticIdentifiers.OnlyClassTypesCanContainDestructors:
                case CompilerDiagnosticIdentifiers.StructsCannotContainExplicitParameterlessConstructors:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveMemberDeclaration))
                    {
                        break;
                    }

                    CodeFixRegistrator.RemoveMemberDeclaration(context, diagnostic, memberDeclaration);
                    break;
                }

                case CompilerDiagnosticIdentifiers.NameOfDestructorMustMatchNameOfClass:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RenameDestructorToMatchClassName))
                    {
                        break;
                    }

                    if (!(memberDeclaration is DestructorDeclarationSyntax destructorDeclaration))
                    {
                        break;
                    }

                    if (!(memberDeclaration.Parent is ClassDeclarationSyntax classDeclaration))
                    {
                        break;
                    }

                    if (classDeclaration.Identifier.ValueText.Length == 0)
                    {
                        break;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        "Rename destructor to match class name",
                        cancellationToken =>
                        {
                            DestructorDeclarationSyntax newNode = destructorDeclaration.WithIdentifier(classDeclaration.Identifier.WithTriviaFrom(destructorDeclaration.Identifier));

                            return(context.Document.ReplaceNodeAsync(destructorDeclaration, newNode, cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);
                    break;
                }

                case CompilerDiagnosticIdentifiers.CannotChangeTupleElementNameWhenOverridingInheritedMember:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RenameTupleElement))
                    {
                        break;
                    }

                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    if (memberDeclaration is MethodDeclarationSyntax methodDeclaration)
                    {
                        IMethodSymbol methodSymbol = semanticModel.GetDeclaredSymbol(methodDeclaration, context.CancellationToken);

                        if (!(methodSymbol.ReturnType is INamedTypeSymbol tupleType))
                        {
                            break;
                        }

                        if (!tupleType.IsTupleType)
                        {
                            break;
                        }

                        if (!(methodSymbol.OverriddenMethod?.ReturnType is INamedTypeSymbol baseTupleType))
                        {
                            break;
                        }

                        if (!baseTupleType.IsTupleType)
                        {
                            break;
                        }

                        ImmutableArray <IFieldSymbol> elements     = tupleType.TupleElements;
                        ImmutableArray <IFieldSymbol> baseElements = baseTupleType.TupleElements;

                        if (elements.Length != baseElements.Length)
                        {
                            break;
                        }

                        int i = 0;
                        while (i < elements.Length)
                        {
                            if (elements[i].Name != baseElements[i].Name)
                            {
                                break;
                            }

                            i++;
                        }

                        if (i == elements.Length)
                        {
                            break;
                        }

                        TupleElementSyntax tupleElement = ((TupleTypeSyntax)methodDeclaration.ReturnType).Elements[i];

                        CodeAction codeAction = CodeAction.Create(
                            $"Rename '{elements[i].Name}' to '{baseElements[i].Name}'",
                            ct => RenameTupleElementAsync(context.Document, methodDeclaration, tupleElement, elements[i], baseElements[i].Name, semanticModel, ct),
                            GetEquivalenceKey(diagnostic));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }
                    else if (memberDeclaration is PropertyDeclarationSyntax propertyDeclaration)
                    {
                        IPropertySymbol propertySymbol = semanticModel.GetDeclaredSymbol(propertyDeclaration, context.CancellationToken);

                        if (!(propertySymbol.Type is INamedTypeSymbol tupleType))
                        {
                            break;
                        }

                        if (!tupleType.IsTupleType)
                        {
                            break;
                        }

                        if (!(propertySymbol.OverriddenProperty?.Type is INamedTypeSymbol baseTupleType))
                        {
                            break;
                        }

                        if (!baseTupleType.IsTupleType)
                        {
                            break;
                        }

                        ImmutableArray <IFieldSymbol> elements     = tupleType.TupleElements;
                        ImmutableArray <IFieldSymbol> baseElements = baseTupleType.TupleElements;

                        if (elements.Length != baseElements.Length)
                        {
                            break;
                        }

                        int i = 0;
                        while (i < elements.Length)
                        {
                            if (elements[i].Name != baseElements[i].Name)
                            {
                                break;
                            }

                            i++;
                        }

                        if (i == elements.Length)
                        {
                            break;
                        }

                        TupleElementSyntax tupleElement = ((TupleTypeSyntax)propertyDeclaration.Type).Elements[i];

                        CodeAction codeAction = CodeAction.Create(
                            $"Rename '{elements[i].Name}' to '{baseElements[i].Name}'",
                            ct => RenameTupleElementAsync(context.Document, propertyDeclaration, tupleElement, elements[i], baseElements[i].Name, semanticModel, ct),
                            GetEquivalenceKey(diagnostic));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.MethodsWithVariableArgumentsAreNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.ArgumentTypeIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.ReturnTypeIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.TypeOfVariableIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.IdentifierDifferingOnlyInCaseIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.OverloadedMethodDifferingOnlyInRefOrOutOrInArrayRankIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.OverloadedMethodDifferingOnlyByUnnamedArrayTypesIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.IdentifierIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.BaseTypeIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.ArraysAsAttributeArgumentsIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.ConstraintTypeIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.TypeIsNotCLSCompliantBecauseBaseInterfaceIsNotCLSCompliant:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.MarkDeclarationAsNonCLSCompliant))
                    {
                        break;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        $"Mark {CSharpFacts.GetTitle(memberDeclaration)} as non-CLS-compliant",
                        ct => MarkDeclarationAsNonCLSCompliantAsync(context.Document, memberDeclaration, ct),
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);
                    break;
                }

                case CompilerDiagnosticIdentifiers.ExplicitInterfaceDeclarationIsNotMemberOfInterface:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddParameterToExplicitlyImplementedInterfaceMember))
                    {
                        break;
                    }

                    var context2 = new CommonFixContext(
                        context.Document,
                        GetEquivalenceKey(diagnostic),
                        await context.GetSemanticModelAsync().ConfigureAwait(false),
                        context.CancellationToken);

                    CodeAction codeAction = AddParameterToInterfaceMemberRefactoring.ComputeRefactoringForExplicitImplementation(context2, memberDeclaration);

                    if (codeAction != null)
                    {
                        context.RegisterCodeFix(codeAction, diagnostic);
                    }

                    break;
                }
                }
            }
        }
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsEnabled(CodeFixIdentifiers.ChangeMethodReturnType))
            {
                return;
            }

            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out SyntaxNode node, predicate: f => f.IsKind(SyntaxKind.MethodDeclaration, SyntaxKind.LocalFunctionStatement)))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.BodyCannotBeIteratorBlockBecauseTypeIsNotIteratorInterfaceType:
                {
                    if (!Settings.IsEnabled(CodeFixIdentifiers.ChangeMethodReturnType))
                    {
                        break;
                    }

                    BlockSyntax body = (node is MethodDeclarationSyntax methodDeclaration)
                                ? methodDeclaration.Body
                                : ((LocalFunctionStatementSyntax)node).Body;

                    Debug.Assert(body != null, node.ToString());

                    if (body == null)
                    {
                        break;
                    }

                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    ITypeSymbol           typeSymbol           = null;
                    HashSet <ITypeSymbol> typeSymbols          = null;
                    INamedTypeSymbol      ienumerableOfTSymbol = null;

                    foreach (SyntaxNode descendant in body.DescendantNodes(descendIntoChildren: f => !CSharpFacts.IsFunction(f.Kind())))
                    {
                        if (!descendant.IsKind(SyntaxKind.YieldReturnStatement))
                        {
                            continue;
                        }

                        var yieldReturn = (YieldStatementSyntax)descendant;

                        ExpressionSyntax expression = yieldReturn.Expression;

                        if (expression == null)
                        {
                            continue;
                        }

                        var namedTypeSymbol = semanticModel.GetTypeSymbol(expression, context.CancellationToken) as INamedTypeSymbol;

                        if (namedTypeSymbol?.IsErrorType() != false)
                        {
                            continue;
                        }

                        if (typeSymbol == null)
                        {
                            typeSymbol = namedTypeSymbol;
                        }
                        else
                        {
                            if (typeSymbols == null)
                            {
                                typeSymbols = new HashSet <ITypeSymbol>()
                                {
                                    typeSymbol
                                };
                            }

                            if (!typeSymbols.Add(namedTypeSymbol))
                            {
                                continue;
                            }
                        }

                        if (ienumerableOfTSymbol == null)
                        {
                            ienumerableOfTSymbol = semanticModel.GetTypeByMetadataName("System.Collections.Generic.IEnumerable`1");
                        }

                        CodeFixRegistrator.ChangeTypeOrReturnType(
                            context,
                            diagnostic,
                            node,
                            ienumerableOfTSymbol.Construct(namedTypeSymbol),
                            semanticModel,
                            additionalKey: SymbolDisplay.ToMinimalDisplayString(namedTypeSymbol, semanticModel, node.SpanStart, SymbolDisplayFormats.Default));
                    }

                    break;
                }
                }
            }
        }