Example #1
0
        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindNode(root, context.Span, out SyntaxNode node))
            {
                return;
            }

            Diagnostic diagnostic = context.Diagnostics[0];

            for (SyntaxNode parent = node.Parent; parent != null; parent = parent.Parent)
            {
                if (parent is MemberDeclarationSyntax memberDeclaration)
                {
                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    ISymbol symbol = semanticModel.GetSymbol(node, context.CancellationToken);

                    if (symbol?.IsErrorType() != false)
                    {
                        return;
                    }

                    SyntaxDebug.Assert(SyntaxInfo.ModifierListInfo(memberDeclaration).IsStatic, memberDeclaration);

                    if (SyntaxInfo.ModifierListInfo(memberDeclaration).IsStatic)
                    {
                        if (IsEnabled(diagnostic.Id, CodeFixIdentifiers.MakeMemberNonStatic, context.Document, root.SyntaxTree))
                        {
                            ModifiersCodeFixRegistrator.RemoveModifier(
                                context,
                                diagnostic,
                                memberDeclaration,
                                SyntaxKind.StaticKeyword,
                                title: $"Make containing {CSharpFacts.GetTitle(memberDeclaration)} non-static",
                                additionalKey: CodeFixIdentifiers.MakeMemberNonStatic);
                        }

                        if (IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddStaticModifier, context.Document, root.SyntaxTree))
                        {
                            AddStaticModifier(context, diagnostic, node, semanticModel);
                        }
                    }

                    return;
                }
                else if (parent is ConstructorInitializerSyntax)
                {
                    if (IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddStaticModifier, context.Document, root.SyntaxTree))
                    {
                        SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                        AddStaticModifier(context, diagnostic, node, semanticModel);
                    }

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

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

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out ClassDeclarationSyntax classDeclaration))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.StaticClassCannotDeriveFromType:
                {
                    ModifiersCodeFixRegistrator.RemoveModifier(
                        context,
                        diagnostic,
                        classDeclaration,
                        SyntaxKind.StaticKeyword,
                        title: "Make class non-static");

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

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

            if (!TryFindToken(root, context.Span.Start, out SyntaxToken token))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.DuplicateModifier:
                {
                    ModifiersCodeFixRegistrator.RemoveModifier(
                        context,
                        diagnostic,
                        token.Parent,
                        token,
                        additionalKey: CodeFixIdentifiers.RemoveDuplicateModifier);

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

            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.MemberDoesNotHideAccessibleMember:
                {
                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, memberDeclaration, SyntaxKind.NewKeyword);

                    break;
                }
                }
            }
        }
        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out TypeDeclarationSyntax typeDeclaration))
            {
                return;
            }

            Diagnostic diagnostic = context.Diagnostics[0];
            Document   document   = context.Document;

            CodeAction codeAction = CodeAction.Create(
                ModifiersCodeFixRegistrator.GetRemoveModifierTitle(SyntaxKind.PartialKeyword),
                ct =>
            {
                TypeDeclarationSyntax newTypeDeclaration = typeDeclaration.ReplaceNodes(
                    typeDeclaration.Members.OfType <MethodDeclarationSyntax>().Where(f => f.Modifiers.Contains(SyntaxKind.PartialKeyword) && f.BodyOrExpressionBody() != null),
                    (f, _) => f.RemoveModifier(SyntaxKind.PartialKeyword));

                int count = newTypeDeclaration.Members.Count;

                for (int i = count - 1; i >= 0; i--)
                {
                    if (newTypeDeclaration.Members[i] is MethodDeclarationSyntax method &&
                        method.Modifiers.Contains(SyntaxKind.PartialKeyword))
                    {
                        newTypeDeclaration = SyntaxRefactorings.RemoveMember(newTypeDeclaration, method);
                    }
                }
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsAnyCodeFixEnabled(
                    CodeFixIdentifiers.AddStaticModifier,
                    CodeFixIdentifiers.MakeMemberNonStatic))
            {
                return;
            }

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

            if (!TryFindNode(root, context.Span, out SyntaxNode node))
            {
                return;
            }

            Diagnostic diagnostic = context.Diagnostics[0];

            for (SyntaxNode parent = node.Parent; parent != null; parent = parent.Parent)
            {
                if (parent is MemberDeclarationSyntax memberDeclaration)
                {
                    Debug.Assert(memberDeclaration.GetModifiers().Contains(SyntaxKind.StaticKeyword), memberDeclaration.ToString());

                    if (memberDeclaration.GetModifiers().Contains(SyntaxKind.StaticKeyword))
                    {
                        if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.MakeMemberNonStatic))
                        {
                            ModifiersCodeFixRegistrator.RemoveModifier(
                                context,
                                diagnostic,
                                memberDeclaration,
                                SyntaxKind.StaticKeyword,
                                title: $"Make containing {memberDeclaration.GetTitle()} non-static",
                                additionalKey: CodeFixIdentifiers.MakeMemberNonStatic);
                        }

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

                        if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddStaticModifier))
                        {
                            AddStaticModifier(context, diagnostic, node, semanticModel);
                        }
                    }

                    return;
                }
                else if (parent is ConstructorInitializerSyntax)
                {
                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddStaticModifier))
                    {
                        AddStaticModifier(context, diagnostic, node, semanticModel);
                    }

                    return;
                }
            }
        }
Example #7
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindToken(root, context.Span.Start, out SyntaxToken token))
            {
                return;
            }

            Debug.Assert(token.Kind() == SyntaxKind.UnsafeKeyword, token.Kind().ToString());

            if (token.Kind() != SyntaxKind.UnsafeKeyword)
            {
                return;
            }

            Diagnostic diagnostic = context.Diagnostics[0];

            SyntaxNode parent = token.Parent;

            if (parent is UnsafeStatementSyntax unsafeStatement)
            {
                CodeAction codeAction = CodeAction.Create(
                    "Remove unsafe context",
                    ct => context.Document.ReplaceNodeAsync(unsafeStatement, RefactoringUtility.RemoveUnsafeContext(unsafeStatement), ct),
                    GetEquivalenceKey(diagnostic));

                context.RegisterCodeFix(codeAction, diagnostic);
            }
            else
            {
                ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, parent, token);
            }
        }
Example #8
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out ParameterSyntax parameter))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case DiagnosticIdentifiers.OverridingMemberCannotChangeParamsModifier:
                {
                    if (parameter.IsParams())
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, parameter, SyntaxKind.ParamsKeyword);
                    }
                    else
                    {
                        ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, parameter, SyntaxKind.ParamsKeyword);
                    }

                    break;
                }
                }
            }
        }
Example #9
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsAnyEnabled(
                    CodeFixIdentifiers.AddOverrideModifier,
                    CodeFixIdentifiers.AddNewModifier,
                    CodeFixIdentifiers.RemoveMemberDeclaration))
            {
                return;
            }

            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.MemberHidesInheritedMemberUseNewKeywordIfHidingWasIntended:
                {
                    if (Settings.IsEnabled(CodeFixIdentifiers.AddNewModifier))
                    {
                        ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, memberDeclaration, SyntaxKind.NewKeyword, additionalKey: nameof(SyntaxKind.NewKeyword));
                    }

                    if (Settings.IsEnabled(CodeFixIdentifiers.RemoveMemberDeclaration))
                    {
                        CodeFixRegistrator.RemoveMemberDeclaration(context, diagnostic, memberDeclaration);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.MemberHidesInheritedMemberToMakeCurrentMethodOverrideThatImplementationAddOverrideKeyword:
                {
                    if (Settings.IsEnabled(CodeFixIdentifiers.AddOverrideModifier) &&
                        !SyntaxInfo.ModifierListInfo(memberDeclaration).IsStatic)
                    {
                        ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, memberDeclaration, SyntaxKind.OverrideKeyword, additionalKey: nameof(SyntaxKind.OverrideKeyword));
                    }

                    if (Settings.IsEnabled(CodeFixIdentifiers.AddNewModifier))
                    {
                        ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, memberDeclaration, SyntaxKind.NewKeyword, additionalKey: nameof(SyntaxKind.NewKeyword));
                    }

                    if (Settings.IsEnabled(CodeFixIdentifiers.RemoveMemberDeclaration))
                    {
                        CodeFixRegistrator.RemoveMemberDeclaration(context, diagnostic, memberDeclaration);
                    }

                    break;
                }
                }
            }
        }
Example #10
0
        private static void AddStaticModifier(CodeFixContext context, Diagnostic diagnostic, SyntaxNode node, string additionalKey = null)
        {
            if (node.IsKind(SyntaxKind.ConstructorDeclaration) &&
                ((ConstructorDeclarationSyntax)node).ParameterList?.Parameters.Any() == true)
            {
                return;
            }

            ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, node, SyntaxKind.StaticKeyword, additionalKey: additionalKey);
        }
        private void AddStaticModifier(
            CodeFixContext context,
            Diagnostic diagnostic,
            SyntaxNode node,
            SemanticModel semanticModel)
        {
            ISymbol symbol = semanticModel.GetSymbol(node, context.CancellationToken);

            if (symbol == null)
            {
                return;
            }

            SyntaxNode syntax = symbol.GetSyntaxOrDefault(context.CancellationToken);

            if (syntax == null)
            {
                return;
            }

            if (syntax.Kind() == SyntaxKind.VariableDeclarator)
            {
                syntax = syntax.Parent?.Parent;
            }

            Debug.Assert(syntax.IsKind(SyntaxKind.EventDeclaration, SyntaxKind.EventFieldDeclaration, SyntaxKind.FieldDeclaration, SyntaxKind.MethodDeclaration, SyntaxKind.PropertyDeclaration), syntax.ToString());

            if (!(syntax is MemberDeclarationSyntax memberDeclaration))
            {
                return;
            }

            if (memberDeclaration.GetModifiers().Contains(SyntaxKind.StaticKeyword))
            {
                return;
            }

            Document document = context.Document;

            SyntaxTree tree = memberDeclaration.SyntaxTree;

            if (tree != node.SyntaxTree)
            {
                document = context.Solution().GetDocument(tree);
            }

            ModifiersCodeFixRegistrator.AddModifier(
                context,
                document,
                diagnostic,
                memberDeclaration,
                SyntaxKind.StaticKeyword,
                title: $"Make '{symbol.Name}' static",
                additionalKey: CodeFixIdentifiers.AddStaticModifier);
        }
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out TypeDeclarationSyntax typeDeclaration))
            {
                return;
            }

            ModifiersCodeFixRegistrator.RemoveModifier(context, context.Diagnostics[0], typeDeclaration, SyntaxKind.PartialKeyword);
        }
Example #13
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out ParameterSyntax parameter))
            {
                return;
            }

            ModifiersCodeFixRegistrator.AddModifier(
                context,
                context.Diagnostics[0],
                parameter,
                SyntaxKind.InKeyword);
        }
        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            Diagnostic diagnostic = context.Diagnostics[0];

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

            if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveNewModifier, context.Document, root.SyntaxTree))
            {
                return;
            }

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

            ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, memberDeclaration, SyntaxKind.NewKeyword);
        }
Example #15
0
        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out ParameterSyntax parameter))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case DiagnosticIdentifiers.OverridingMemberShouldNotChangeParamsModifier:
                {
                    if (parameter.IsParams())
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, parameter, SyntaxKind.ParamsKeyword);
                    }
                    else
                    {
                        ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, parameter, SyntaxKind.ParamsKeyword);
                    }

                    break;
                }

                case DiagnosticIdentifiers.MakeParameterRefReadOnly:
                case DiagnosticIdentifiers.DoNotPassNonReadOnlyStructByReadOnlyReference:
                {
                    if (parameter.Modifiers.Contains(SyntaxKind.InKeyword))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, parameter, SyntaxKind.InKeyword);
                    }
                    else
                    {
                        ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, parameter, SyntaxKind.InKeyword);
                    }

                    break;
                }
                }
            }
        }
Example #16
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out ParameterSyntax parameter))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case DiagnosticIdentifiers.AddParameterToDocumentationComment:
                {
                    var refactoring = new AddParameterToDocumentationCommentRefactoring();

                    CodeAction codeAction = CodeAction.Create(
                        "Add parameter to documentation comment",
                        cancellationToken => refactoring.RefactorAsync(context.Document, parameter, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.OverridingMemberCannotChangeParamsModifier:
                {
                    if (parameter.IsParams())
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, parameter, SyntaxKind.ParamsKeyword);
                    }
                    else
                    {
                        ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, parameter, SyntaxKind.ParamsKeyword);
                    }

                    break;
                }
                }
            }
        }
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            Diagnostic diagnostic = context.Diagnostics[0];

            if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveDuplicateModifier))
            {
                return;
            }

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

            if (!TryFindToken(root, context.Span.Start, out SyntaxToken token))
            {
                return;
            }

            ModifiersCodeFixRegistrator.RemoveModifier(
                context,
                diagnostic,
                token.Parent,
                token,
                additionalKey: CodeFixIdentifiers.RemoveDuplicateModifier);
        }
Example #18
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddDocumentationComment) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeMethodReturnType) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.MemberTypeMustMatchOverriddenMemberType) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddPartialModifier) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.MakeContainingClassAbstract) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveParametersFromStaticConstructor) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveMemberDeclaration) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RenameDestructorToMatchClassName) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RenameTupleElement))
            {
                return;
            }

            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.IsCodeFixEnabled(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.IsCodeFixEnabled(CodeFixIdentifiers.ChangeMethodReturnType))
                    {
                        break;
                    }

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

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

                    ITypeSymbol typeSymbol = methodSymbol.OverriddenMethod.ReturnType;

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

                    break;
                }

                case CompilerDiagnosticIdentifiers.PartialMethodsMustHaveVoidReturnType:
                {
                    if (!Settings.IsCodeFixEnabled(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.IsCodeFixEnabled(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.First();

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

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

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

                    break;
                }

                case CompilerDiagnosticIdentifiers.MissingPartialModifier:
                case CompilerDiagnosticIdentifiers.PartialMethodMustBeDeclaredInPartialClassOrPartialStruct:
                {
                    if (!Settings.IsCodeFixEnabled(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:
                    {
                        node = memberDeclaration;
                        break;
                    }
                    }

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

                    if (node == null)
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, node, SyntaxKind.PartialKeyword);
                    break;
                }

                case CompilerDiagnosticIdentifiers.MemberIsAbstractButItIsContainedInNonAbstractClass:
                {
                    if (!Settings.IsCodeFixEnabled(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.IsCodeFixEnabled(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.IsCodeFixEnabled(CodeFixIdentifiers.RemoveMemberDeclaration))
                    {
                        break;
                    }

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

                case CompilerDiagnosticIdentifiers.NameOfDestructorMustMatchNameOfClass:
                {
                    if (!Settings.IsCodeFixEnabled(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.IsCodeFixEnabled(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;
                }
                }
            }
        }
Example #19
0
        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out BaseListSyntax baseList))
            {
                return;
            }

            if (baseList.ContainsDiagnostics)
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.BaseClassMustComeBeforeAnyInterface:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.MoveBaseClassBeforeAnyInterface))
                    {
                        return;
                    }

                    SeparatedSyntaxList <BaseTypeSyntax> types = baseList.Types;

                    if (types.Count > 1)
                    {
                        BaseTypeSyntax baseType = types.First(f => context.Span.Contains(f.Span));

                        CodeAction codeAction = CodeAction.Create(
                            $"Move '{baseType.Type}' before any interface",
                            cancellationToken =>
                            {
                                BaseTypeSyntax firstType = types[0];

                                SeparatedSyntaxList <BaseTypeSyntax> newTypes = types
                                                                                .Replace(baseType, firstType.WithTriviaFrom(baseType))
                                                                                .ReplaceAt(0, baseType.WithTriviaFrom(firstType));

                                BaseListSyntax newBaseList = baseList.WithTypes(newTypes);

                                return(context.Document.ReplaceNodeAsync(baseList, newBaseList, cancellationToken));
                            },
                            GetEquivalenceKey(diagnostic));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.StaticClassCannotDeriveFromType:
                case CompilerDiagnosticIdentifiers.StaticClassCannotImplementInterfaces:
                {
                    if (!(baseList.Parent is ClassDeclarationSyntax classDeclaration))
                    {
                        break;
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.MakeClassNonStatic))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(
                            context,
                            diagnostic,
                            classDeclaration,
                            SyntaxKind.StaticKeyword,
                            title: "Make class non-static",
                            additionalKey: CodeFixIdentifiers.MakeClassNonStatic);
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveBaseList))
                    {
                        CodeAction codeAction = CodeAction.Create(
                            "Remove base list",
                            cancellationToken =>
                            {
                                SyntaxToken token = baseList.GetFirstToken().GetPreviousToken();

                                SyntaxTriviaList trivia = token.TrailingTrivia.EmptyIfWhitespace()
                                                          .AddRange(baseList.GetLeadingTrivia().EmptyIfWhitespace())
                                                          .AddRange(baseList.GetTrailingTrivia());

                                ClassDeclarationSyntax newNode = classDeclaration
                                                                 .ReplaceToken(token, token.WithTrailingTrivia(trivia))
                                                                 .WithBaseList(null);

                                return(context.Document.ReplaceNodeAsync(classDeclaration, newNode, cancellationToken));
                            },
                            base.GetEquivalenceKey(diagnostic, CodeFixIdentifiers.RemoveBaseList));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }

                    break;
                }
                }
            }
        }
Example #20
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out ClassDeclarationSyntax classDeclaration))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case DiagnosticIdentifiers.MakeClassStatic:
                {
                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    ISymbol symbol = semanticModel.GetDeclaredSymbol(classDeclaration, context.CancellationToken);

                    ImmutableArray <SyntaxReference> syntaxReferences = symbol.DeclaringSyntaxReferences;

                    if (!syntaxReferences.Any())
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.AddModifier(
                        context,
                        diagnostic,
                        ImmutableArray.CreateRange(syntaxReferences, f => f.GetSyntax()),
                        SyntaxKind.StaticKeyword,
                        title: "Make class static");

                    break;
                }

                case DiagnosticIdentifiers.AddStaticModifierToAllPartialClassDeclarations:
                {
                    ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, classDeclaration, SyntaxKind.StaticKeyword);
                    break;
                }

                case DiagnosticIdentifiers.ImplementExceptionConstructors:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Generate exception constructors",
                        cancellationToken =>
                        {
                            return(ImplementExceptionConstructorsRefactoring.RefactorAsync(
                                       context.Document,
                                       classDeclaration,
                                       cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.UseAttributeUsageAttribute:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Use AttributeUsageAttribute",
                        cancellationToken =>
                        {
                            return(UseAttributeUsageAttributeRefactoring.RefactorAsync(
                                       context.Document,
                                       classDeclaration,
                                       cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);
                    break;
                }
                }
            }
        }
Example #21
0
        public sealed 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 DiagnosticIdentifiers.FormatDeclarationBraces:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Format braces",
                        cancellationToken => FormatDeclarationBracesRefactoring.RefactorAsync(context.Document, memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.RemoveRedundantOverridingMember:
                {
                    CodeAction codeAction = CodeAction.Create(
                        $"Remove {memberDeclaration.GetTitle()}",
                        cancellationToken => context.Document.RemoveMemberAsync(memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.AddDefaultAccessModifier:
                {
                    var accessibility = (Accessibility)Enum.Parse(
                        typeof(Accessibility),
                        context.Diagnostics[0].Properties[nameof(Accessibility)]);

                    CodeAction codeAction = CodeAction.Create(
                        "Add default access modifier",
                        cancellationToken => AddDefaultAccessModifierRefactoring.RefactorAsync(context.Document, memberDeclaration, accessibility, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.AddEmptyLineBetweenDeclarations:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Add empty line",
                        cancellationToken => AddEmptyLineBetweenDeclarationsRefactoring.RefactorAsync(context.Document, memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.RemoveRedundantSealedModifier:
                {
                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, memberDeclaration, SyntaxKind.SealedKeyword);
                    break;
                }

                case DiagnosticIdentifiers.AvoidSemicolonAtEndOfDeclaration:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Remove unnecessary semicolon",
                        cancellationToken => AvoidSemicolonAtEndOfDeclarationRefactoring.RefactorAsync(context.Document, memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.ReorderModifiers:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Reorder modifiers",
                        cancellationToken => ReorderModifiersRefactoring.RefactorAsync(context.Document, memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.MarkFieldAsReadOnly:
                {
                    var fieldDeclaration = (FieldDeclarationSyntax)memberDeclaration;

                    SeparatedSyntaxList <VariableDeclaratorSyntax> declarators = fieldDeclaration.Declaration.Variables;

                    string title = (declarators.Count == 1)
                                ? $"Mark '{declarators[0].Identifier.ValueText}' as read-only"
                                : "Mark fields as read-only";

                    ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, fieldDeclaration, SyntaxKind.ReadOnlyKeyword, title: title);
                    break;
                }

                case DiagnosticIdentifiers.UseConstantInsteadOfField:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Use constant instead of field",
                        cancellationToken => UseConstantInsteadOfFieldRefactoring.RefactorAsync(context.Document, (FieldDeclarationSyntax)memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.UseReadOnlyAutoProperty:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Use read-only auto-property",
                        cancellationToken => UseReadOnlyAutoPropertyRefactoring.RefactorAsync(context.Document, (PropertyDeclarationSyntax)memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.ReplaceCommentWithDocumentationComment:
                {
                    CodeAction codeAction = CodeAction.Create(
                        ReplaceCommentWithDocumentationCommentRefactoring.Title,
                        cancellationToken => ReplaceCommentWithDocumentationCommentRefactoring.RefactorAsync(context.Document, memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);
                    break;
                }
                }
            }
        }
Example #22
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsAnyCodeFixEnabled(
                    CodeFixIdentifiers.AddArgumentList,
                    CodeFixIdentifiers.ReorderModifiers,
                    CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue,
                    CodeFixIdentifiers.ReturnDefaultValue,
                    CodeFixIdentifiers.AddMissingType))
            {
                return;
            }

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

            if (!TryFindToken(root, context.Span.Start, out SyntaxToken token))
            {
                return;
            }

            SyntaxKind kind = token.Kind();

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.OperatorCannotBeAppliedToOperandOfType:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddArgumentList))
                    {
                        break;
                    }

                    if (kind != SyntaxKind.QuestionToken)
                    {
                        break;
                    }

                    if (!token.IsParentKind(SyntaxKind.ConditionalAccessExpression))
                    {
                        break;
                    }

                    var conditionalAccess = (ConditionalAccessExpressionSyntax)token.Parent;

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

                    ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(conditionalAccess.Expression, context.CancellationToken);

                    if (typeSymbol == null ||
                        typeSymbol.IsErrorType() ||
                        !typeSymbol.IsValueType ||
                        typeSymbol.IsConstructedFrom(SpecialType.System_Nullable_T))
                    {
                        break;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        "Remove '?' operator",
                        cancellationToken =>
                        {
                            var textChange = new TextChange(token.Span, "");
                            return(context.Document.WithTextChangeAsync(textChange, cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

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

                case CompilerDiagnosticIdentifiers.PartialModifierCanOnlyAppearImmediatelyBeforeClassStructInterfaceOrVoid:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReorderModifiers))
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.MoveModifier(context, diagnostic, token.Parent, token);
                    break;
                }

                case CompilerDiagnosticIdentifiers.ValueCannotBeUsedAsDefaultParameter:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue))
                    {
                        break;
                    }

                    if (!(token.Parent is ParameterSyntax parameter))
                    {
                        break;
                    }

                    ExpressionSyntax value = parameter.Default?.Value;

                    if (value == null)
                    {
                        break;
                    }

                    if (value.Kind() != SyntaxKind.NullLiteralExpression)
                    {
                        break;
                    }

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

                    CodeFixRegistrator.ReplaceNullWithDefaultValue(context, diagnostic, value, semanticModel);
                    break;
                }

                case CompilerDiagnosticIdentifiers.ObjectOfTypeConvertibleToTypeIsRequired:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReturnDefaultValue))
                    {
                        break;
                    }

                    if (token.Kind() != SyntaxKind.ReturnKeyword)
                    {
                        break;
                    }

                    if (!token.IsParentKind(SyntaxKind.ReturnStatement))
                    {
                        break;
                    }

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

                    ISymbol symbol = semanticModel.GetEnclosingSymbol(token.SpanStart, context.CancellationToken);

                    if (symbol == null)
                    {
                        break;
                    }

                    SymbolKind symbolKind = symbol.Kind;

                    ITypeSymbol typeSymbol = null;

                    if (symbolKind == SymbolKind.Method)
                    {
                        var methodSymbol = (IMethodSymbol)symbol;

                        typeSymbol = methodSymbol.ReturnType;

                        if (methodSymbol.IsAsync &&
                            (typeSymbol is INamedTypeSymbol namedTypeSymbol))
                        {
                            ImmutableArray <ITypeSymbol> typeArguments = namedTypeSymbol.TypeArguments;

                            if (typeArguments.Any())
                            {
                                typeSymbol = typeArguments[0];
                            }
                        }
                    }
                    else if (symbolKind == SymbolKind.Property)
                    {
                        typeSymbol = ((IPropertySymbol)symbol).Type;
                    }
                    else
                    {
                        Debug.Fail(symbolKind.ToString());
                    }

                    if (typeSymbol == null)
                    {
                        break;
                    }

                    if (typeSymbol.Kind == SymbolKind.ErrorType)
                    {
                        break;
                    }

                    if (!typeSymbol.SupportsExplicitDeclaration())
                    {
                        break;
                    }

                    var returnStatement = (ReturnStatementSyntax)token.Parent;

                    CodeAction codeAction = CodeAction.Create(
                        "Return default value",
                        cancellationToken =>
                        {
                            ExpressionSyntax expression = typeSymbol.ToDefaultValueSyntax(semanticModel, returnStatement.SpanStart);

                            ReturnStatementSyntax newNode = returnStatement.WithExpression(expression);

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

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

                case CompilerDiagnosticIdentifiers.TypeExpected:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddMissingType))
                    {
                        break;
                    }

                    if (token.Kind() != SyntaxKind.CloseParenToken)
                    {
                        break;
                    }

                    if (!(token.Parent is DefaultExpressionSyntax defaultExpression))
                    {
                        break;
                    }

                    if (!(defaultExpression.Type is IdentifierNameSyntax identifierName))
                    {
                        break;
                    }

                    if (!identifierName.IsMissing)
                    {
                        break;
                    }

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

                    TypeInfo typeInfo = semanticModel.GetTypeInfo(defaultExpression, context.CancellationToken);

                    ITypeSymbol convertedType = typeInfo.ConvertedType;

                    if (convertedType?.SupportsExplicitDeclaration() != true)
                    {
                        break;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        $"Add type '{SymbolDisplay.GetMinimalString(convertedType, semanticModel, defaultExpression.SpanStart)}'",
                        cancellationToken =>
                        {
                            TypeSyntax newNode = convertedType.ToMinimalTypeSyntax(semanticModel, defaultExpression.SpanStart);

                            newNode = newNode
                                      .WithTriviaFrom(identifierName)
                                      .WithFormatterAnnotation();

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

                    context.RegisterCodeFix(codeAction, diagnostic);
                    break;
                }
                }
            }
        }
Example #23
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.CS1591_MissingXmlCommentForPubliclyVisibleTypeOrMember:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddDocumentationComment, context.Document, root.SyntaxTree))
                    {
                        break;
                    }

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

                    context.RegisterCodeFix(codeAction, diagnostic);

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

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

                case CompilerDiagnosticIdentifiers.CS0508_MethodReturnTypeMustMatchOverriddenMethodReturnType:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeMethodReturnType, context.Document, root.SyntaxTree))
                    {
                        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.CS0766_PartialMethodsMustHaveVoidReturnType:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeMethodReturnType, context.Document, root.SyntaxTree))
                    {
                        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'",
                        ct =>
                        {
                            return(context.Document.Solution().ReplaceNodesAsync(
                                       new MethodDeclarationSyntax[] { methodDeclaration, otherPart },
                                       (node, _) => node.WithReturnType(CSharpFactory.VoidType().WithTriviaFrom(node.ReturnType)),
                                       ct));
                        },
                        GetEquivalenceKey(diagnostic));

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

                case CompilerDiagnosticIdentifiers.CS1715_MemberTypeMustMatchOverriddenMemberType:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.MemberTypeMustMatchOverriddenMemberType, context.Document, root.SyntaxTree))
                    {
                        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.CS0260_MissingPartialModifier:
                case CompilerDiagnosticIdentifiers.CS0751_PartialMethodMustBeDeclaredInPartialClassOrPartialStruct:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddPartialModifier, context.Document, root.SyntaxTree))
                    {
                        break;
                    }

                    SyntaxNode node = null;

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

                        break;
                    }

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

                    SyntaxDebug.Assert(node != null, memberDeclaration);

                    if (node == null)
                    {
                        break;
                    }

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

                case CompilerDiagnosticIdentifiers.CS0513_MemberIsAbstractButItIsContainedInNonAbstractClass:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.MakeContainingClassAbstract, context.Document, root.SyntaxTree))
                    {
                        break;
                    }

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

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

                    break;
                }

                case CompilerDiagnosticIdentifiers.CS0132_StaticConstructorMustBeParameterless:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveParametersFromStaticConstructor, context.Document, root.SyntaxTree))
                    {
                        break;
                    }

                    var constructorDeclaration = (ConstructorDeclarationSyntax)memberDeclaration;

                    CodeAction codeAction = CodeAction.Create(
                        "Remove parameters",
                        ct =>
                        {
                            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, ct));
                        },
                        GetEquivalenceKey(diagnostic));

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

                case CompilerDiagnosticIdentifiers.CS0541_ExplicitInterfaceDeclarationCanOnlyBeDeclaredInClassOrStruct:
                case CompilerDiagnosticIdentifiers.CS0525_InterfacesCannotContainFields:
                case CompilerDiagnosticIdentifiers.CS0567_InterfacesCannotContainOperators:
                case CompilerDiagnosticIdentifiers.CS0524_InterfacesCannotDeclareTypes:
                case CompilerDiagnosticIdentifiers.CS0575_OnlyClassTypesCanContainDestructors:
                case CompilerDiagnosticIdentifiers.CS0568_StructsCannotContainExplicitParameterlessConstructors:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveMemberDeclaration, context.Document, root.SyntaxTree))
                    {
                        break;
                    }

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

                case CompilerDiagnosticIdentifiers.CS0574_NameOfDestructorMustMatchNameOfClass:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RenameDestructorToMatchClassName, context.Document, root.SyntaxTree))
                    {
                        break;
                    }

                    if (memberDeclaration is not DestructorDeclarationSyntax destructorDeclaration)
                    {
                        break;
                    }

                    if (memberDeclaration.Parent is not ClassDeclarationSyntax classDeclaration)
                    {
                        break;
                    }

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

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

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

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

                case CompilerDiagnosticIdentifiers.CS8139_CannotChangeTupleElementNameWhenOverridingInheritedMember:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RenameTupleElement, context.Document, root.SyntaxTree))
                    {
                        break;
                    }

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

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

                        if (methodSymbol.ReturnType is not INamedTypeSymbol tupleType)
                        {
                            break;
                        }

                        if (!tupleType.IsTupleType)
                        {
                            break;
                        }

                        if (methodSymbol.OverriddenMethod?.ReturnType is not 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 not INamedTypeSymbol tupleType)
                        {
                            break;
                        }

                        if (!tupleType.IsTupleType)
                        {
                            break;
                        }

                        if (propertySymbol.OverriddenProperty?.Type is not 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.CS3000_MethodsWithVariableArgumentsAreNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3001_ArgumentTypeIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3002_ReturnTypeIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3003_TypeOfVariableIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3005_IdentifierDifferingOnlyInCaseIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3006_OverloadedMethodDifferingOnlyInRefOrOutOrInArrayRankIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3007_OverloadedMethodDifferingOnlyByUnnamedArrayTypesIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3008_IdentifierIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3009_BaseTypeIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3016_ArraysAsAttributeArgumentsIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3024_ConstraintTypeIsNotCLSCompliant:
                case CompilerDiagnosticIdentifiers.CS3027_TypeIsNotCLSCompliantBecauseBaseInterfaceIsNotCLSCompliant:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.MarkDeclarationAsNonCLSCompliant, context.Document, root.SyntaxTree))
                    {
                        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.CS0539_ExplicitInterfaceDeclarationIsNotMemberOfInterface:
                {
                    if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddParameterToExplicitlyImplementedInterfaceMember, context.Document, root.SyntaxTree))
                    {
                        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;
                }
                }
            }
        }
Example #24
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddArgumentList) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReorderModifiers) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReturnDefaultValue) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddMissingType) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveSemicolon) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveConditionalAccess) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeForEachType))
            {
                return;
            }

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

            if (!TryFindToken(root, context.Span.Start, out SyntaxToken token))
            {
                return;
            }

            SyntaxKind kind = token.Kind();

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.OperatorCannotBeAppliedToOperandOfType:
                {
                    if (kind == SyntaxKind.QuestionToken &&
                        token.Parent is ConditionalAccessExpressionSyntax conditionalAccess)
                    {
                        SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                        ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(conditionalAccess.Expression, context.CancellationToken);

                        if (typeSymbol?.IsErrorType() == false &&
                            !typeSymbol.IsConstructedFrom(SpecialType.System_Nullable_T))
                        {
                            if (typeSymbol.IsValueType)
                            {
                                if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveConditionalAccess))
                                {
                                    CodeAction codeAction = CodeAction.Create(
                                        "Remove '?' operator",
                                        cancellationToken =>
                                        {
                                            var textChange = new TextChange(token.Span, "");
                                            return(context.Document.WithTextChangeAsync(textChange, cancellationToken));
                                        },
                                        GetEquivalenceKey(diagnostic));

                                    context.RegisterCodeFix(codeAction, diagnostic);
                                }
                            }
                            else if (typeSymbol.IsReferenceType)
                            {
                                if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddArgumentList) &&
                                    conditionalAccess.WhenNotNull is MemberBindingExpressionSyntax memberBindingExpression)
                                {
                                    ConditionalAccessExpressionSyntax newNode = conditionalAccess.WithWhenNotNull(
                                        InvocationExpression(
                                            memberBindingExpression.WithoutTrailingTrivia(),
                                            ArgumentList().WithTrailingTrivia(memberBindingExpression.GetTrailingTrivia())));

                                    CodeAction codeAction = CodeAction.Create(
                                        "Add argument list",
                                        cancellationToken => context.Document.ReplaceNodeAsync(conditionalAccess, newNode, cancellationToken),
                                        GetEquivalenceKey(diagnostic));

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

                        if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddArgumentList))
                        {
                            break;
                        }

                        if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveConditionalAccess))
                        {
                        }
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.PartialModifierCanOnlyAppearImmediatelyBeforeClassStructInterfaceOrVoid:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReorderModifiers))
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.MoveModifier(context, diagnostic, token.Parent, token);
                    break;
                }

                case CompilerDiagnosticIdentifiers.ValueCannotBeUsedAsDefaultParameter:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue))
                    {
                        break;
                    }

                    if (!(token.Parent is ParameterSyntax parameter))
                    {
                        break;
                    }

                    ExpressionSyntax value = parameter.Default?.Value;

                    if (value == null)
                    {
                        break;
                    }

                    if (value.Kind() != SyntaxKind.NullLiteralExpression)
                    {
                        break;
                    }

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

                    CodeFixRegistrator.ReplaceNullWithDefaultValue(context, diagnostic, value, semanticModel);
                    break;
                }

                case CompilerDiagnosticIdentifiers.ObjectOfTypeConvertibleToTypeIsRequired:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReturnDefaultValue))
                    {
                        break;
                    }

                    if (token.Kind() != SyntaxKind.ReturnKeyword)
                    {
                        break;
                    }

                    if (!token.IsParentKind(SyntaxKind.ReturnStatement))
                    {
                        break;
                    }

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

                    ISymbol symbol = semanticModel.GetEnclosingSymbol(token.SpanStart, context.CancellationToken);

                    if (symbol == null)
                    {
                        break;
                    }

                    SymbolKind symbolKind = symbol.Kind;

                    ITypeSymbol typeSymbol = null;

                    if (symbolKind == SymbolKind.Method)
                    {
                        var methodSymbol = (IMethodSymbol)symbol;

                        typeSymbol = methodSymbol.ReturnType;

                        if (methodSymbol.IsAsync &&
                            (typeSymbol is INamedTypeSymbol namedTypeSymbol))
                        {
                            ImmutableArray <ITypeSymbol> typeArguments = namedTypeSymbol.TypeArguments;

                            if (typeArguments.Any())
                            {
                                typeSymbol = typeArguments[0];
                            }
                        }
                    }
                    else if (symbolKind == SymbolKind.Property)
                    {
                        typeSymbol = ((IPropertySymbol)symbol).Type;
                    }
                    else
                    {
                        Debug.Fail(symbolKind.ToString());
                    }

                    if (typeSymbol == null)
                    {
                        break;
                    }

                    if (typeSymbol.Kind == SymbolKind.ErrorType)
                    {
                        break;
                    }

                    if (!typeSymbol.SupportsExplicitDeclaration())
                    {
                        break;
                    }

                    var returnStatement = (ReturnStatementSyntax)token.Parent;

                    CodeAction codeAction = CodeAction.Create(
                        "Return default value",
                        cancellationToken =>
                        {
                            ExpressionSyntax expression = typeSymbol.ToDefaultValueSyntax(semanticModel, returnStatement.SpanStart);

                            ReturnStatementSyntax newNode = returnStatement.WithExpression(expression);

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

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

                case CompilerDiagnosticIdentifiers.TypeExpected:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddMissingType))
                    {
                        break;
                    }

                    if (token.Kind() != SyntaxKind.CloseParenToken)
                    {
                        break;
                    }

                    if (!(token.Parent is DefaultExpressionSyntax defaultExpression))
                    {
                        break;
                    }

                    if (!(defaultExpression.Type is IdentifierNameSyntax identifierName))
                    {
                        break;
                    }

                    if (!identifierName.IsMissing)
                    {
                        break;
                    }

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

                    TypeInfo typeInfo = semanticModel.GetTypeInfo(defaultExpression, context.CancellationToken);

                    ITypeSymbol convertedType = typeInfo.ConvertedType;

                    if (convertedType?.SupportsExplicitDeclaration() != true)
                    {
                        break;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        $"Add type '{SymbolDisplay.GetMinimalString(convertedType, semanticModel, defaultExpression.SpanStart)}'",
                        cancellationToken =>
                        {
                            TypeSyntax newNode = convertedType.ToMinimalTypeSyntax(semanticModel, defaultExpression.SpanStart);

                            newNode = newNode
                                      .WithTriviaFrom(identifierName)
                                      .WithFormatterAnnotation();

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

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

                case CompilerDiagnosticIdentifiers.SemicolonAfterMethodOrAccessorBlockIsNotValid:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveSemicolon))
                    {
                        break;
                    }

                    if (token.Kind() != SyntaxKind.SemicolonToken)
                    {
                        break;
                    }

                    switch (token.Parent)
                    {
                    case MethodDeclarationSyntax methodDeclaration:
                    {
                        BlockSyntax body = methodDeclaration.Body;

                        if (body == null)
                        {
                            break;
                        }

                        CodeAction codeAction = CodeAction.Create(
                            "Remove semicolon",
                            cancellationToken =>
                                {
                                    SyntaxTriviaList trivia = body
                                                              .GetTrailingTrivia()
                                                              .EmptyIfWhitespace()
                                                              .AddRange(token.LeadingTrivia.EmptyIfWhitespace())
                                                              .AddRange(token.TrailingTrivia);

                                    MethodDeclarationSyntax newNode = methodDeclaration
                                                                      .WithBody(body.WithTrailingTrivia(trivia))
                                                                      .WithSemicolonToken(default(SyntaxToken));

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

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

                    case PropertyDeclarationSyntax propertyDeclaration:
                    {
                        AccessorListSyntax accessorList = propertyDeclaration.AccessorList;

                        if (accessorList == null)
                        {
                            break;
                        }

                        CodeAction codeAction = CodeAction.Create(
                            "Remove semicolon",
                            cancellationToken =>
                                {
                                    SyntaxTriviaList trivia = accessorList
                                                              .GetTrailingTrivia()
                                                              .EmptyIfWhitespace()
                                                              .AddRange(token.LeadingTrivia.EmptyIfWhitespace())
                                                              .AddRange(token.TrailingTrivia);

                                    PropertyDeclarationSyntax newNode = propertyDeclaration
                                                                        .WithAccessorList(accessorList.WithTrailingTrivia(trivia))
                                                                        .WithSemicolonToken(default(SyntaxToken));

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

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

                    case AccessorDeclarationSyntax accessorDeclaration:
                    {
                        BlockSyntax body = accessorDeclaration.Body;

                        if (body == null)
                        {
                            break;
                        }

                        CodeAction codeAction = CodeAction.Create(
                            "Remove semicolon",
                            cancellationToken =>
                                {
                                    SyntaxTriviaList trivia = body
                                                              .GetTrailingTrivia()
                                                              .EmptyIfWhitespace()
                                                              .AddRange(token.LeadingTrivia.EmptyIfWhitespace())
                                                              .AddRange(token.TrailingTrivia);

                                    AccessorDeclarationSyntax newNode = accessorDeclaration
                                                                        .WithBody(body.WithTrailingTrivia(trivia))
                                                                        .WithSemicolonToken(default(SyntaxToken));

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

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

                    break;
                }

                case CompilerDiagnosticIdentifiers.CannotConvertType:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeForEachType))
                    {
                        break;
                    }

                    if (token.Kind() != SyntaxKind.ForEachKeyword)
                    {
                        break;
                    }

                    if (!(token.Parent is ForEachStatementSyntax forEachStatement))
                    {
                        break;
                    }

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

                    ForEachStatementInfo info = semanticModel.GetForEachStatementInfo(forEachStatement);

                    ITypeSymbol typeSymbol = info.ElementType;

                    if (typeSymbol.SupportsExplicitDeclaration())
                    {
                        CodeFixRegistrator.ChangeType(context, diagnostic, forEachStatement.Type, typeSymbol, semanticModel, CodeFixIdentifiers.ChangeForEachType);
                    }

                    CodeFixRegistrator.ChangeTypeToVar(context, diagnostic, forEachStatement.Type, CodeFixIdentifiers.ChangeTypeToVar);
                    break;
                }
                }
            }
        }
Example #25
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeAccessibility) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddStaticModifier) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveThisModifier) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.MakeContainingClassNonStatic) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddPartialModifier) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveOutModifier) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveRefModifier) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddModifierAbstract))
            {
                return;
            }

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

            if (!TryFindToken(root, context.Span.Start, out SyntaxToken token))
            {
                return;
            }

            SyntaxNode node = token.Parent;

            if (!node.Kind().SupportsModifiers())
            {
                node = node.FirstAncestor(f => f.Kind().SupportsModifiers());
            }

            Debug.Assert(node != null, $"{nameof(node)} is null");

            if (node == null)
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.ModifierIsNotValidForThisItem:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        break;
                    }

                    SyntaxTokenList modifiers = node.GetModifiers();

                    if (modifiers.Contains(token))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, token);
                        break;
                    }
                    else if (IsInterfaceMemberOrExplicitInterfaceImplementation(node))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifiers(context, diagnostic, node, modifiers, f =>
                            {
                                switch (f.Kind())
                                {
                                case SyntaxKind.PublicKeyword:
                                case SyntaxKind.ProtectedKeyword:
                                case SyntaxKind.InternalKeyword:
                                case SyntaxKind.PrivateKeyword:
                                case SyntaxKind.StaticKeyword:
                                case SyntaxKind.VirtualKeyword:
                                case SyntaxKind.OverrideKeyword:
                                case SyntaxKind.AbstractKeyword:
                                    {
                                        return(true);
                                    }
                                }

                                return(false);
                            });
                    }
                    else if (node.IsKind(SyntaxKind.IndexerDeclaration))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.StaticKeyword);
                    }
                    else if (node.IsKind(SyntaxKind.PropertyDeclaration))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.AsyncKeyword);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.MoreThanOneProtectionModifier:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, token);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.AccessibilityModifiersMayNotBeUsedOnAccessorsInInterface:
                case CompilerDiagnosticIdentifiers.AccessModifiersAreNotAllowedOnStaticConstructors:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveAccessModifiers(context, diagnostic, node);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.ModifiersCannotBePlacedOnEventAccessorDeclarations:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifiers(context, diagnostic, node);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.OnlyMethodsClassesStructsOrInterfacesMayBePartial:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.PartialKeyword);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.ClassCannotBeBothStaticAndSealed:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.StaticKeyword, additionalKey: nameof(SyntaxKind.StaticKeyword));
                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.SealedKeyword, additionalKey: nameof(SyntaxKind.SealedKeyword));
                    break;
                }

                case CompilerDiagnosticIdentifiers.FieldCanNotBeBothVolatileAndReadOnly:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        break;
                    }

                    var fieldDeclaration = (FieldDeclarationSyntax)node;

                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, fieldDeclaration, SyntaxKind.VolatileKeyword, additionalKey: nameof(SyntaxKind.VolatileKeyword));
                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, fieldDeclaration, SyntaxKind.ReadOnlyKeyword, additionalKey: nameof(SyntaxKind.ReadOnlyKeyword));
                    break;
                }

                case CompilerDiagnosticIdentifiers.NewProtectedMemberDeclaredInSealedClass:
                case CompilerDiagnosticIdentifiers.StaticClassesCannotContainProtectedMembers:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeAccessibility))
                    {
                        ModifiersCodeFixRegistrator.ChangeAccessibility(context, diagnostic, node, _publicOrInternalOrPrivate);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.VirtualOrAbstractmembersCannotBePrivate:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeAccessibility))
                    {
                        ModifiersCodeFixRegistrator.ChangeAccessibility(context, diagnostic, node, _publicOrInternalOrProtected);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.AbstractPropertiesCannotHavePrivateAccessors:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveAccessModifiers(context, diagnostic, node, additionalKey: CodeFixIdentifiers.RemoveInvalidModifier);
                    }

                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeAccessibility))
                    {
                        ModifiersCodeFixRegistrator.ChangeAccessibility(context, diagnostic, node, _publicOrInternalOrProtected);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.StaticMemberCannotBeMarkedOverrideVirtualOrAbstract:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        break;
                    }

                    if (!node.IsParentKind(SyntaxKind.ClassDeclaration) ||
                        !((ClassDeclarationSyntax)node.Parent).Modifiers.Contains(SyntaxKind.StaticKeyword))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.StaticKeyword, additionalKey: nameof(SyntaxKind.StaticKeyword));
                    }

                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.OverrideKeyword, additionalKey: nameof(SyntaxKind.OverrideKeyword));
                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.VirtualKeyword, additionalKey: nameof(SyntaxKind.VirtualKeyword));
                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.AbstractKeyword, additionalKey: nameof(SyntaxKind.AbstractKeyword));
                    break;
                }

                case CompilerDiagnosticIdentifiers.AsyncModifierCanOnlyBeUsedInMethodsThatHaveBody:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.AsyncKeyword);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.PartialMethodCannotHaveAccessModifiersOrVirtualAbstractOverrideNewSealedOrExternModifiers:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.RemoveModifiers(context, diagnostic, node, f =>
                        {
                            switch (f.Kind())
                            {
                            case SyntaxKind.PublicKeyword:
                            case SyntaxKind.ProtectedKeyword:
                            case SyntaxKind.InternalKeyword:
                            case SyntaxKind.PrivateKeyword:
                            case SyntaxKind.VirtualKeyword:
                            case SyntaxKind.AbstractKeyword:
                            case SyntaxKind.OverrideKeyword:
                            case SyntaxKind.NewKeyword:
                            case SyntaxKind.SealedKeyword:
                            case SyntaxKind.ExternKeyword:
                                {
                                    return(true);
                                }
                            }

                            return(false);
                        });

                    break;
                }

                case CompilerDiagnosticIdentifiers.ExtensionMethodMustBeStatic:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddStaticModifier))
                    {
                        AddStaticModifier(context, diagnostic, node, CodeFixIdentifiers.AddStaticModifier);
                    }

                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveThisModifier))
                    {
                        var methodDeclaration = (MethodDeclarationSyntax)node;

                        ParameterSyntax parameter = methodDeclaration.ParameterList.Parameters.First();

                        SyntaxToken modifier = parameter.Modifiers.Find(SyntaxKind.ThisKeyword);

                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, parameter, modifier, additionalKey: CodeFixIdentifiers.RemoveThisModifier);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.ExtensionMethodMustBeDefinedInNonGenericStaticClass:
                {
                    if (!node.IsKind(SyntaxKind.ClassDeclaration))
                    {
                        return;
                    }

                    var classDeclaration = (ClassDeclarationSyntax)node;

                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddStaticModifier) &&
                        !classDeclaration.IsStatic())
                    {
                        AddStaticModifier(context, diagnostic, node, CodeFixIdentifiers.AddStaticModifier);
                    }

                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveThisModifier))
                    {
                        IEnumerable <ParameterSyntax> thisParameters = classDeclaration.Members
                                                                       .Where(f => f.IsKind(SyntaxKind.MethodDeclaration))
                                                                       .Cast <MethodDeclarationSyntax>()
                                                                       .Select(f => f.ParameterList?.Parameters.FirstOrDefault())
                                                                       .Where(f => f?.Modifiers.Contains(SyntaxKind.ThisKeyword) == true);

                        ModifiersCodeFixRegistrator.RemoveModifier(
                            context,
                            diagnostic,
                            thisParameters,
                            SyntaxKind.ThisKeyword,
                            title: "Remove 'this' modifier from extension methods",
                            additionalKey: CodeFixIdentifiers.RemoveThisModifier);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.NoDefiningDeclarationFoundForImplementingDeclarationOfPartialMethod:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.PartialKeyword);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.MethodHasParameterModifierThisWhichIsNotOnFirstParameter:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveThisModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, token.Parent, token);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.CannotDeclareInstanceMembersInStaticClass:
                case CompilerDiagnosticIdentifiers.StaticClassesCannotHaveInstanceConstructors:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddStaticModifier))
                    {
                        AddStaticModifier(context, diagnostic, node, CodeFixIdentifiers.AddStaticModifier);
                    }

                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.MakeContainingClassNonStatic))
                    {
                        var classDeclaration = (ClassDeclarationSyntax)node.Parent;

                        ModifiersCodeFixRegistrator.RemoveModifier(
                            context,
                            diagnostic,
                            classDeclaration,
                            classDeclaration.Modifiers.Find(SyntaxKind.StaticKeyword),
                            title: "Make containing class non-static",
                            additionalKey: CodeFixIdentifiers.MakeContainingClassNonStatic);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.ElementsDefinedInNamespaceCannotBeExplicitlyDeclaredAsPrivateProtectedOrProtectedInternal:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeAccessibility))
                    {
                        ModifiersCodeFixRegistrator.ChangeAccessibility(context, diagnostic, node, _publicOrInternal);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.NamespaceAlreadyContainsDefinition:
                case CompilerDiagnosticIdentifiers.TypeAlreadyContainsDefinition:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddPartialModifier))
                    {
                        break;
                    }

                    if (!node.IsKind(
                            SyntaxKind.ClassDeclaration,
                            SyntaxKind.StructDeclaration,
                            SyntaxKind.InterfaceDeclaration,
                            SyntaxKind.MethodDeclaration))
                    {
                        return;
                    }

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

                    ISymbol symbol = semanticModel.GetDeclaredSymbol(node, context.CancellationToken);

                    ImmutableArray <SyntaxReference> syntaxReferences = symbol.DeclaringSyntaxReferences;

                    if (syntaxReferences.Length <= 1)
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.AddModifier(
                        context,
                        diagnostic,
                        ImmutableArray.CreateRange(syntaxReferences, f => f.GetSyntax(context.CancellationToken)),
                        SyntaxKind.PartialKeyword);

                    break;
                }

                case CompilerDiagnosticIdentifiers.NoSuitableMethodFoundToOverride:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveInvalidModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.OverrideKeyword);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.AsyncMethodsCannotHaveRefOrOutParameters:
                case CompilerDiagnosticIdentifiers.IteratorsCannotHaveRefOrOutParameters:
                case CompilerDiagnosticIdentifiers.ReadOnlyFieldCannotBePassedAsRefOrOutValue:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveRefModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.RefKeyword, additionalKey: nameof(SyntaxKind.RefKeyword));
                    }

                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveOutModifier))
                    {
                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, node, SyntaxKind.OutKeyword, additionalKey: nameof(SyntaxKind.OutKeyword));
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.CannotHaveInstancePropertyOrFieldInitializersInStruct:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddStaticModifier))
                    {
                        AddStaticModifier(context, diagnostic, node);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.MemberMustDeclareBodyBecauseItIsNotMarkedAbstractExternOrPartial:
                {
                    if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddModifierAbstract) &&
                        node.Kind() == SyntaxKind.MethodDeclaration &&
                        (node.Parent as ClassDeclarationSyntax)?.Modifiers.Contains(SyntaxKind.AbstractKeyword) == true)
                    {
                        ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, node, SyntaxKind.AbstractKeyword);
                    }

                    break;
                }
                }
            }
        }
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddDocumentationComment) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.ChangeMethodReturnType) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.MemberTypeMustMatchOverriddenMemberType) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddPartialModifier) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.MakeContainingClassAbstract) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveParametersFromStaticConstructor) &&
                !Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveMemberDeclaration))
            {
                return;
            }

            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.IsCodeFixEnabled(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.IsCodeFixEnabled(CodeFixIdentifiers.ChangeMethodReturnType))
                    {
                        break;
                    }

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

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

                    ITypeSymbol typeSymbol = methodSymbol.OverriddenMethod.ReturnType;

                    if (typeSymbol?.IsErrorType() == false)
                    {
                        CodeAction codeAction = CodeAction.Create(
                            $"Change return type to '{SymbolDisplay.GetMinimalString(typeSymbol, semanticModel, memberDeclaration.SpanStart)}'",
                            cancellationToken => MemberTypeMustMatchOverriddenMemberTypeRefactoring.RefactorAsync(context.Document, memberDeclaration, typeSymbol, semanticModel, cancellationToken),
                            GetEquivalenceKey(diagnostic));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.PartialMethodsMustHaveVoidReturnType:
                {
                    if (!Settings.IsCodeFixEnabled(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, rewrittenNode) => node.WithReturnType(CSharpFactory.VoidType().WithTriviaFrom(node.ReturnType)),
                                       cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

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

                case CompilerDiagnosticIdentifiers.MemberTypeMustMatchOverriddenMemberType:
                {
                    if (!Settings.IsCodeFixEnabled(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.First();

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

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

                    if (typeSymbol?.IsErrorType() == false)
                    {
                        string title = $"Change type to '{SymbolDisplay.GetMinimalString(typeSymbol, semanticModel, memberDeclaration.SpanStart)}'";

                        CodeAction codeAction = CodeAction.Create(
                            title,
                            cancellationToken => MemberTypeMustMatchOverriddenMemberTypeRefactoring.RefactorAsync(context.Document, memberDeclaration, typeSymbol, semanticModel, cancellationToken),
                            GetEquivalenceKey(diagnostic));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.MissingPartialModifier:
                case CompilerDiagnosticIdentifiers.PartialMethodMustBeDeclaredWithinPartialClassOrPartialStruct:
                {
                    if (!Settings.IsCodeFixEnabled(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:
                    {
                        node = memberDeclaration;
                        break;
                    }
                    }

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

                    if (node == null)
                    {
                        break;
                    }

                    ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, node, SyntaxKind.PartialKeyword);
                    break;
                }

                case CompilerDiagnosticIdentifiers.MemberIsAbstractButItIsContainedInNonAbstractClass:
                {
                    if (!Settings.IsCodeFixEnabled(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.IsCodeFixEnabled(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:
                {
                    if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveMemberDeclaration))
                    {
                        break;
                    }

                    CodeFixRegistrator.RemoveMember(context, diagnostic, memberDeclaration);
                    break;
                }
                }
            }
        }
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            if (!Settings.IsAnyEnabled(
                    CodeFixIdentifiers.WrapInUnsafeStatement,
                    CodeFixIdentifiers.MakeContainingDeclarationUnsafe))
            {
                return;
            }

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

            if (!TryFindNode(root, context.Span, out SyntaxNode node))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.PointersAndFixedSizeBuffersMayOnlyBeUsedInUnsafeContext:
                {
                    bool fStatement         = false;
                    bool fMemberDeclaration = false;

                    foreach (SyntaxNode ancestor in node.AncestorsAndSelf())
                    {
                        if (fStatement &&
                            fMemberDeclaration)
                        {
                            break;
                        }

                        if (!fStatement &&
                            ancestor is StatementSyntax)
                        {
                            fStatement = true;

                            if (!Settings.IsEnabled(CodeFixIdentifiers.WrapInUnsafeStatement))
                            {
                                continue;
                            }

                            var statement = (StatementSyntax)ancestor;

                            if (statement.IsKind(SyntaxKind.Block) &&
                                statement.Parent is StatementSyntax)
                            {
                                statement = (StatementSyntax)statement.Parent;
                            }

                            if (statement.IsKind(SyntaxKind.UnsafeStatement))
                            {
                                break;
                            }

                            CodeAction codeAction = CodeAction.Create(
                                "Wrap in unsafe block",
                                cancellationToken =>
                                {
                                    BlockSyntax block = (statement.IsKind(SyntaxKind.Block))
                                                ? (BlockSyntax)statement
                                                : SyntaxFactory.Block(statement);

                                    UnsafeStatementSyntax unsafeStatement = SyntaxFactory.UnsafeStatement(block).WithFormatterAnnotation();

                                    return(context.Document.ReplaceNodeAsync(statement, unsafeStatement, cancellationToken));
                                },
                                GetEquivalenceKey(diagnostic, CodeFixIdentifiers.WrapInUnsafeStatement));

                            context.RegisterCodeFix(codeAction, diagnostic);
                        }
                        else if (!fMemberDeclaration &&
                                 ancestor is MemberDeclarationSyntax)
                        {
                            fMemberDeclaration = true;

                            if (!Settings.IsEnabled(CodeFixIdentifiers.MakeContainingDeclarationUnsafe))
                            {
                                continue;
                            }

                            if (!CSharpFacts.CanHaveModifiers(ancestor.Kind()))
                            {
                                continue;
                            }

                            ModifiersCodeFixRegistrator.AddModifier(
                                context,
                                diagnostic,
                                ancestor,
                                SyntaxKind.UnsafeKeyword,
                                title: "Make containing declaration unsafe",
                                additionalKey: CodeFixIdentifiers.MakeContainingDeclarationUnsafe);
                        }
                    }

                    break;
                }
                }
            }
        }
Example #28
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 DiagnosticIdentifiers.RemoveRedundantOverridingMember:
                {
                    CodeAction codeAction = CodeActionFactory.RemoveMemberDeclaration(context.Document, memberDeclaration, equivalenceKey: GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.AddAccessibilityModifiersOrViceVersa:
                {
                    if (diagnostic.Properties.TryGetValue(nameof(Accessibility), out string accessibilityText))
                    {
                        var accessibility = (Accessibility)Enum.Parse(typeof(Accessibility), accessibilityText);

                        CodeAction codeAction = CodeAction.Create(
                            "Add accessibility modifiers",
                            ct =>
                            {
                                MemberDeclarationSyntax newNode = SyntaxAccessibility.WithExplicitAccessibility(memberDeclaration, accessibility);

                                return(context.Document.ReplaceNodeAsync(memberDeclaration, newNode, ct));
                            },
                            GetEquivalenceKey(diagnostic));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }
                    else
                    {
                        CodeAction codeAction = CodeAction.Create(
                            "Remove accessibility modifiers",
                            ct =>
                            {
                                MemberDeclarationSyntax newNode = SyntaxAccessibility.WithoutExplicitAccessibility(memberDeclaration);

                                return(context.Document.ReplaceNodeAsync(memberDeclaration, newNode, ct));
                            },
                            GetEquivalenceKey(diagnostic));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }

                    break;
                }

                case DiagnosticIdentifiers.RemoveRedundantSealedModifier:
                {
                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, memberDeclaration, SyntaxKind.SealedKeyword);
                    break;
                }

                case DiagnosticIdentifiers.AvoidSemicolonAtEndOfDeclaration:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Remove unnecessary semicolon",
                        cancellationToken => AvoidSemicolonAtEndOfDeclarationRefactoring.RefactorAsync(context.Document, memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.OrderModifiers:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Order modifiers",
                        ct => OrderModifiersAsync(context.Document, memberDeclaration, ct),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.MakeFieldReadOnly:
                {
                    var fieldDeclaration = (FieldDeclarationSyntax)memberDeclaration;

                    SeparatedSyntaxList <VariableDeclaratorSyntax> declarators = fieldDeclaration.Declaration.Variables;

                    string title = (declarators.Count == 1)
                                ? $"Make '{declarators[0].Identifier.ValueText}' read-only"
                                : "Make fields read-only";

                    ModifiersCodeFixRegistrator.AddModifier(context, diagnostic, fieldDeclaration, SyntaxKind.ReadOnlyKeyword, title: title);
                    break;
                }

                case DiagnosticIdentifiers.UseConstantInsteadOfField:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Use constant instead of field",
                        cancellationToken => UseConstantInsteadOfFieldRefactoring.RefactorAsync(context.Document, (FieldDeclarationSyntax)memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.UseReadOnlyAutoProperty:
                {
                    CodeAction codeAction = CodeAction.Create(
                        "Use read-only auto-property",
                        cancellationToken => UseReadOnlyAutoPropertyAsync(context.Document, (PropertyDeclarationSyntax)memberDeclaration, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.ConvertCommentToDocumentationComment:
                {
                    CodeAction codeAction = CodeAction.Create(
                        ConvertCommentToDocumentationCommentRefactoring.Title,
                        cancellationToken => ConvertCommentToDocumentationCommentRefactoring.RefactorAsync(context.Document, memberDeclaration, context.Span, cancellationToken),
                        GetEquivalenceKey(diagnostic));

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

                case DiagnosticIdentifiers.MakeMethodExtensionMethod:
                {
                    var methodDeclaration = (MethodDeclarationSyntax)memberDeclaration;

                    CodeAction codeAction = CodeAction.Create(
                        "Make method an extension method",
                        cancellationToken =>
                        {
                            ParameterSyntax parameter = methodDeclaration.ParameterList.Parameters[0];

                            ParameterSyntax newParameter = ModifierList.Insert(parameter, SyntaxKind.ThisKeyword);

                            return(context.Document.ReplaceNodeAsync(parameter, newParameter, cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);
                    break;
                }
                }
            }
        }
Example #29
0
        public override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindNode(root, context.Span, out ExpressionSyntax expression))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.CannotImplicitlyConvertTypeExplicitConversionExists:
                {
                    SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                    TypeInfo typeInfo = semanticModel.GetTypeInfo(expression, context.CancellationToken);

                    ITypeSymbol type          = typeInfo.Type;
                    ITypeSymbol convertedType = typeInfo.ConvertedType;

                    if ((type is INamedTypeSymbol namedType) &&
                        namedType.IsNullableType())
                    {
                        if (convertedType?.SpecialType == SpecialType.System_Boolean ||
                            AddComparisonWithBooleanLiteralRefactoring.IsCondition(expression))
                        {
                            if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddComparisonWithBooleanLiteral))
                            {
                                CodeAction codeAction = CodeAction.Create(
                                    AddComparisonWithBooleanLiteralRefactoring.GetTitle(expression),
                                    cancellationToken => AddComparisonWithBooleanLiteralRefactoring.RefactorAsync(context.Document, expression, cancellationToken),
                                    GetEquivalenceKey(diagnostic, CodeFixIdentifiers.AddComparisonWithBooleanLiteral));

                                context.RegisterCodeFix(codeAction, diagnostic);
                            }
                        }
                        else if (SymbolEqualityComparer.Default.Equals(namedType.TypeArguments[0], convertedType))
                        {
                            if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.UseCoalesceExpression))
                            {
                                CodeAction codeAction = CodeAction.Create(
                                    "Use coalesce expression",
                                    cancellationToken =>
                                    {
                                        ExpressionSyntax defaultValue = convertedType.GetDefaultValueSyntax(context.Document.GetDefaultSyntaxOptions());

                                        ExpressionSyntax newNode = CoalesceExpression(expression.WithoutTrivia(), defaultValue)
                                                                   .WithTriviaFrom(expression)
                                                                   .Parenthesize()
                                                                   .WithFormatterAnnotation();

                                        return(context.Document.ReplaceNodeAsync(expression, newNode, cancellationToken));
                                    },
                                    GetEquivalenceKey(diagnostic, CodeFixIdentifiers.UseCoalesceExpression));

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

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeMemberTypeAccordingToReturnExpression) &&
                        expression.IsParentKind(SyntaxKind.ReturnStatement, SyntaxKind.YieldReturnStatement))
                    {
                        ChangeMemberTypeRefactoring.ComputeCodeFix(context, diagnostic, expression, semanticModel);
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddCastExpression))
                    {
                        CodeFixRegistrator.AddCastExpression(context, diagnostic, expression, convertedType, semanticModel);
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeTypeAccordingToInitializer))
                    {
                        ChangeTypeAccordingToInitializerRefactoring.ComputeCodeFix(context, diagnostic, expression, semanticModel);
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.CreateSingletonArray) &&
                        type?.IsErrorType() == false &&
                        !SymbolEqualityComparer.Default.Equals(type, convertedType) &&
                        (convertedType is IArrayTypeSymbol arrayType) &&
                        semanticModel.IsImplicitConversion(expression, arrayType.ElementType))
                    {
                        CodeAction codeAction = CodeAction.Create(
                            "Create singleton array",
                            cancellationToken => CreateSingletonArrayRefactoring.RefactorAsync(context.Document, expression, arrayType.ElementType, semanticModel, cancellationToken),
                            GetEquivalenceKey(diagnostic, CodeFixIdentifiers.CreateSingletonArray));

                        context.RegisterCodeFix(codeAction, diagnostic);
                    }

                    break;
                }

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

                    CodeAction codeAction = CodeAction.Create(
                        "Use 'unchecked'",
                        cancellationToken =>
                        {
                            CheckedExpressionSyntax newNode = CSharpFactory.UncheckedExpression(expression.WithoutTrivia());

                            newNode = newNode.WithTriviaFrom(expression);

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

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

                case CompilerDiagnosticIdentifiers.ExpressionBeingAssignedMustBeConstant:
                {
                    SyntaxNode parent = expression.Parent;

                    if (parent?.IsKind(SyntaxKind.EqualsValueClause) != true)
                    {
                        break;
                    }

                    parent = parent.Parent;

                    if (parent?.IsKind(SyntaxKind.VariableDeclarator) != true)
                    {
                        break;
                    }

                    parent = parent.Parent;

                    if (!(parent is VariableDeclarationSyntax variableDeclaration))
                    {
                        break;
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveConstModifier) &&
                        variableDeclaration.Parent is LocalDeclarationStatementSyntax localDeclarationStatement)
                    {
                        SyntaxTokenList modifiers = localDeclarationStatement.Modifiers;

                        if (!modifiers.Contains(SyntaxKind.ConstKeyword))
                        {
                            break;
                        }

                        ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, localDeclarationStatement, SyntaxKind.ConstKeyword);
                    }
                    else if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceConstantWithField) &&
                             variableDeclaration.Variables.Count == 1 &&
                             (variableDeclaration.Parent is FieldDeclarationSyntax fieldDeclaration) &&
                             fieldDeclaration.Modifiers.Contains(SyntaxKind.ConstKeyword))
                    {
                        CodeAction codeAction = CodeAction.Create(
                            ReplaceConstantWithFieldRefactoring.Title,
                            cancellationToken => ReplaceConstantWithFieldRefactoring.RefactorAsync(context.Document, fieldDeclaration, cancellationToken),
                            GetEquivalenceKey(diagnostic));

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

                    break;
                }

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

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

                    CodeFixRegistrator.ReplaceNullWithDefaultValue(context, diagnostic, expression, semanticModel);
                    break;
                }

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

                    NullCheckExpressionInfo nullCheck = SyntaxInfo.NullCheckExpressionInfo(expression, allowedStyles: NullCheckStyles.ComparisonToNull);

                    if (!nullCheck.Success)
                    {
                        break;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        "Remove condition",
                        cancellationToken =>
                        {
                            cancellationToken.ThrowIfCancellationRequested();

                            SyntaxNode newRoot = RemoveCondition(root, expression, nullCheck.Style == NullCheckStyles.NotEqualsToNull);

                            cancellationToken.ThrowIfCancellationRequested();

                            return(Task.FromResult(context.Document.WithSyntaxRoot(newRoot)));
                        },
                        GetEquivalenceKey(diagnostic));

                    context.RegisterCodeFix(codeAction, diagnostic);

                    break;
                }

                case CompilerDiagnosticIdentifiers.OnlyAssignmentCallIncrementDecrementAndNewObjectExpressionsCanBeUsedAsStatement:
                {
                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveParentheses) &&
                        expression is ParenthesizedExpressionSyntax parenthesizedExpression &&
                        parenthesizedExpression?.IsMissing == false)
                    {
                        CodeAction codeAction = CodeActionFactory.RemoveParentheses(context.Document, parenthesizedExpression, equivalenceKey: GetEquivalenceKey(diagnostic));

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

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

                    if (expression.Parent is ArrowExpressionClauseSyntax arrowExpresssionClause)
                    {
                        if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeMemberTypeAccordingToReturnExpression))
                        {
                            break;
                        }

                        ChangeMemberTypeRefactoring.ComputeCodeFix(context, diagnostic, expression, semanticModel);
                    }
                    else if (expression.Parent is ExpressionStatementSyntax expressionStatement)
                    {
                        if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddArgumentList) &&
                            expression.IsKind(
                                SyntaxKind.IdentifierName,
                                SyntaxKind.SimpleMemberAccessExpression))
                        {
                            SyntaxNode invocationExpression = InvocationExpression(expression);

                            if (semanticModel.GetSpeculativeMethodSymbol(expression.SpanStart, invocationExpression) != null)
                            {
                                CodeAction codeAction = CodeAction.Create(
                                    "Add argument list",
                                    cancellationToken => context.Document.ReplaceNodeAsync(expression, invocationExpression, cancellationToken),
                                    GetEquivalenceKey(diagnostic, CodeFixIdentifiers.AddArgumentList));

                                context.RegisterCodeFix(codeAction, diagnostic);
                            }
                        }

                        if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceComparisonWithAssignment) &&
                            expression.IsKind(SyntaxKind.EqualsExpression))
                        {
                            BinaryExpressionInfo info = SyntaxInfo.BinaryExpressionInfo(expression);

                            if (!info.Success)
                            {
                                break;
                            }

                            ITypeSymbol leftTypeSymbol = semanticModel.GetTypeSymbol(info.Left, context.CancellationToken);

                            if (leftTypeSymbol?.IsErrorType() != false)
                            {
                                break;
                            }

                            if (!semanticModel.IsImplicitConversion(info.Right, leftTypeSymbol))
                            {
                                break;
                            }

                            CodeAction codeAction = CodeAction.Create(
                                "Replace comparison with assignment",
                                cancellationToken =>
                                {
                                    AssignmentExpressionSyntax simpleAssignment = SimpleAssignmentExpression(info.Left, info.Right).WithTriviaFrom(expression);
                                    return(context.Document.ReplaceNodeAsync(expression, simpleAssignment, cancellationToken));
                                },
                                GetEquivalenceKey(diagnostic, CodeFixIdentifiers.ReplaceComparisonWithAssignment));

                            context.RegisterCodeFix(codeAction, diagnostic);
                        }

                        if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceConditionalExpressionWithIfElse) &&
                            (expression is ConditionalExpressionSyntax conditionalExpression) &&
                            conditionalExpression.Condition != null)
                        {
                            ExpressionSyntax whenTrue  = conditionalExpression.WhenTrue;
                            ExpressionSyntax whenFalse = conditionalExpression.WhenFalse;

                            if (whenTrue != null &&
                                whenFalse != null &&
                                semanticModel.GetTypeSymbol(whenTrue, context.CancellationToken)?.SpecialType == SpecialType.System_Void &&
                                semanticModel.GetTypeSymbol(whenFalse, context.CancellationToken)?.SpecialType == SpecialType.System_Void)
                            {
                                CodeAction codeAction = CodeAction.Create(
                                    "Replace ?: with if-else",
                                    cancellationToken =>
                                    {
                                        IfStatementSyntax newNode = IfStatement(
                                            conditionalExpression.Condition.WalkDownParentheses(),
                                            Block(ExpressionStatement(whenTrue)),
                                            ElseClause(Block(ExpressionStatement(whenFalse))));

                                        newNode = newNode
                                                  .WithTriviaFrom(expressionStatement)
                                                  .WithFormatterAnnotation();

                                        return(context.Document.ReplaceNodeAsync(expressionStatement, newNode, cancellationToken));
                                    },
                                    GetEquivalenceKey(diagnostic, CodeFixIdentifiers.ReplaceConditionalExpressionWithIfElse));

                                context.RegisterCodeFix(codeAction, diagnostic);
                            }
                        }

                        if (semanticModel.GetSymbol(expression, context.CancellationToken)?.IsErrorType() != false)
                        {
                            break;
                        }

                        ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(expression, context.CancellationToken);

                        if (typeSymbol?.IsErrorType() != false)
                        {
                            break;
                        }

                        if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.IntroduceLocalVariable) &&
                            !expressionStatement.IsEmbedded())
                        {
                            bool addAwait = typeSymbol.OriginalDefinition.EqualsOrInheritsFromTaskOfT() &&
                                            semanticModel.GetEnclosingSymbol(expressionStatement.SpanStart, context.CancellationToken).IsAsyncMethod();

                            CodeAction codeAction = CodeAction.Create(
                                IntroduceLocalVariableRefactoring.GetTitle(expression),
                                cancellationToken => IntroduceLocalVariableRefactoring.RefactorAsync(context.Document, expressionStatement, typeSymbol, addAwait, semanticModel, cancellationToken),
                                GetEquivalenceKey(diagnostic, CodeFixIdentifiers.IntroduceLocalVariable));

                            context.RegisterCodeFix(codeAction, diagnostic);
                        }

                        if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.IntroduceField))
                        {
                            CodeAction codeAction = CodeAction.Create(
                                $"Introduce field for '{expression}'",
                                cancellationToken => IntroduceFieldRefactoring.RefactorAsync(context.Document, expressionStatement, typeSymbol, semanticModel, cancellationToken),
                                GetEquivalenceKey(diagnostic, CodeFixIdentifiers.IntroduceField));

                            context.RegisterCodeFix(codeAction, diagnostic);
                        }
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.CannotImplicitlyConvertType:
                {
                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceYieldReturnWithForEach) &&
                        expression.IsParentKind(SyntaxKind.YieldReturnStatement))
                    {
                        SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                        ReplaceYieldReturnWithForEachRefactoring.ComputeCodeFix(context, diagnostic, expression, semanticModel);
                        break;
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeMemberTypeAccordingToReturnExpression) &&
                        expression.IsParentKind(SyntaxKind.ReturnStatement, SyntaxKind.YieldReturnStatement, SyntaxKind.ArrowExpressionClause))
                    {
                        SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                        ChangeMemberTypeRefactoring.ComputeCodeFix(context, diagnostic, expression, semanticModel);
                        break;
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeTypeAccordingToInitializer))
                    {
                        SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                        CodeFixRegistrationResult result = ChangeTypeAccordingToInitializerRefactoring.ComputeCodeFix(context, diagnostic, expression, semanticModel);

                        if (!result.Success)
                        {
                            RemoveAssignmentOfVoidExpression(context, diagnostic, expression, semanticModel);
                        }

                        break;
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceStringLiteralWithCharacterLiteral) &&
                        expression?.Kind() == SyntaxKind.StringLiteralExpression)
                    {
                        var literalExpression = (LiteralExpressionSyntax)expression;

                        if (literalExpression.Token.ValueText.Length == 1)
                        {
                            SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                            if (semanticModel.GetTypeInfo(expression, context.CancellationToken).ConvertedType?.SpecialType == SpecialType.System_Char)
                            {
                                CodeAction codeAction = CodeAction.Create(
                                    "Replace string literal with character literal",
                                    cancellationToken => ReplaceStringLiteralWithCharacterLiteralRefactoring.RefactorAsync(context.Document, literalExpression, cancellationToken),
                                    GetEquivalenceKey(diagnostic, CodeFixIdentifiers.ReplaceStringLiteralWithCharacterLiteral));

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

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.UseYieldReturnInsteadOfReturn) &&
                        expression.IsParentKind(SyntaxKind.ReturnStatement))
                    {
                        var returnStatement = (ReturnStatementSyntax)expression.Parent;

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

                        ISymbol containingSymbol = semanticModel.GetEnclosingSymbol(returnStatement.SpanStart, context.CancellationToken);

                        if (containingSymbol?.Kind == SymbolKind.Method &&
                            ((IMethodSymbol)containingSymbol).ReturnType.OriginalDefinition.IsIEnumerableOrIEnumerableOfT())
                        {
                            CodeAction codeAction = CodeAction.Create(
                                "Use yield return instead of return",
                                cancellationToken => UseYieldReturnInsteadOfReturnRefactoring.RefactorAsync(context.Document, returnStatement, SyntaxKind.YieldReturnStatement, semanticModel, cancellationToken),
                                GetEquivalenceKey(diagnostic, CodeFixIdentifiers.UseYieldReturnInsteadOfReturn));

                            context.RegisterCodeFix(codeAction, diagnostic);
                        }
                    }

                    break;
                }

                case CompilerDiagnosticIdentifiers.LeftHandSideOfAssignmentMustBeVariablePropertyOrIndexer:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveConstModifier))
                    {
                        return;
                    }

                    if (!expression.IsKind(SyntaxKind.IdentifierName))
                    {
                        return;
                    }

                    if (!expression.IsParentKind(SyntaxKind.SimpleAssignmentExpression))
                    {
                        return;
                    }

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

                    SymbolInfo symbolInfo = semanticModel.GetSymbolInfo(expression, context.CancellationToken);

                    if (symbolInfo.CandidateReason != CandidateReason.NotAVariable)
                    {
                        return;
                    }

                    if (!(symbolInfo.CandidateSymbols.SingleOrDefault(shouldThrow: false) is ILocalSymbol localSymbol))
                    {
                        return;
                    }

                    if (!localSymbol.IsConst)
                    {
                        return;
                    }

                    SyntaxNode node = localSymbol.GetSyntaxOrDefault(context.CancellationToken);

                    if (!node.IsKind(SyntaxKind.VariableDeclarator))
                    {
                        return;
                    }

                    node = node.Parent;

                    if (!node.IsKind(SyntaxKind.VariableDeclaration))
                    {
                        return;
                    }

                    node = node.Parent;

                    if (!(node is LocalDeclarationStatementSyntax localDeclaration))
                    {
                        return;
                    }

                    SyntaxToken constModifier = localDeclaration.Modifiers.Find(SyntaxKind.ConstKeyword);

                    if (!constModifier.IsKind(SyntaxKind.ConstKeyword))
                    {
                        return;
                    }

                    ModifiersCodeFixRegistrator.RemoveModifier(context, diagnostic, localDeclaration, constModifier);

                    break;
                }

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

                    SimpleAssignmentExpressionInfo simpleAssignment = SyntaxInfo.SimpleAssignmentExpressionInfo(expression.Parent);

                    if (!simpleAssignment.Success)
                    {
                        return;
                    }

                    if (simpleAssignment.Left != expression)
                    {
                        return;
                    }

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

                    SymbolInfo symbolInfo = semanticModel.GetSymbolInfo(expression, context.CancellationToken);

                    if (symbolInfo.CandidateReason != CandidateReason.NotAVariable)
                    {
                        return;
                    }

                    if (!(symbolInfo.CandidateSymbols.SingleOrDefault(shouldThrow: false) is IFieldSymbol fieldSymbol))
                    {
                        return;
                    }

                    if (fieldSymbol.DeclaredAccessibility != Accessibility.Private)
                    {
                        return;
                    }

                    if (!(fieldSymbol.GetSyntax().Parent.Parent is FieldDeclarationSyntax fieldDeclaration))
                    {
                        return;
                    }

                    TypeDeclarationSyntax containingTypeDeclaration = fieldDeclaration.FirstAncestor <TypeDeclarationSyntax>();

                    if (!expression.Ancestors().Any(f => f == containingTypeDeclaration))
                    {
                        return;
                    }

                    ModifiersCodeFixRegistrator.RemoveModifier(
                        context,
                        diagnostic,
                        fieldDeclaration,
                        SyntaxKind.ReadOnlyKeyword,
                        title: $"Make '{fieldSymbol.Name}' writable");

                    break;
                }
                }
            }
        }
Example #30
0
        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
        {
            SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);

            if (!TryFindFirstAncestorOrSelf(root, context.Span, out ArgumentSyntax argument))
            {
                return;
            }

            foreach (Diagnostic diagnostic in context.Diagnostics)
            {
                switch (diagnostic.Id)
                {
                case CompilerDiagnosticIdentifiers.ArgumentMustBePassedWithRefOrOutKeyword:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddOutModifierToArgument))
                    {
                        return;
                    }

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

                    IParameterSymbol parameter = semanticModel.DetermineParameter(argument, allowCandidate: true, cancellationToken: context.CancellationToken);

                    if (parameter == null)
                    {
                        return;
                    }

                    SyntaxToken refOrOutKeyword = default;

                    if (parameter.RefKind == RefKind.Out)
                    {
                        refOrOutKeyword = Token(SyntaxKind.OutKeyword);
                    }
                    else if (parameter.RefKind == RefKind.Ref)
                    {
                        refOrOutKeyword = Token(SyntaxKind.RefKeyword);
                    }
                    else
                    {
                        return;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        $"Add '{SyntaxFacts.GetText(refOrOutKeyword.Kind())}' modifier",
                        cancellationToken =>
                        {
                            ArgumentSyntax newArgument = argument
                                                         .WithRefOrOutKeyword(refOrOutKeyword)
                                                         .WithFormatterAnnotation();

                            return(context.Document.ReplaceNodeAsync(argument, newArgument, cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

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

                case CompilerDiagnosticIdentifiers.ArgumentShouldNotBePassedWithRefOrOutKeyword:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveRefModifier))
                    {
                        return;
                    }

                    CodeAction codeAction = CodeAction.Create(
                        "Remove 'ref' modifier",
                        cancellationToken =>
                        {
                            ArgumentSyntax newArgument = argument
                                                         .WithRefOrOutKeyword(default(SyntaxToken))
                                                         .PrependToLeadingTrivia(argument.RefOrOutKeyword.GetAllTrivia())
                                                         .WithFormatterAnnotation();

                            return(context.Document.ReplaceNodeAsync(argument, newArgument, cancellationToken));
                        },
                        GetEquivalenceKey(diagnostic));

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

                case CompilerDiagnosticIdentifiers.CannotConvertArgumentType:
                {
                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue))
                    {
                        ExpressionSyntax expression = argument.Expression;

                        if (expression.Kind() == SyntaxKind.NullLiteralExpression &&
                            argument.Parent is ArgumentListSyntax argumentList)
                        {
                            SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                            ImmutableArray <IParameterSymbol> parameterSymbols = FindParameters(argumentList, semanticModel, context.CancellationToken);

                            if (!parameterSymbols.IsDefault)
                            {
                                int index = argumentList.Arguments.IndexOf(argument);

                                IParameterSymbol parameterSymbol = parameterSymbols[index];

                                ITypeSymbol typeSymbol = parameterSymbol.Type;

                                if (typeSymbol.IsValueType)
                                {
                                    CodeFixRegistrator.ReplaceNullWithDefaultValue(
                                        context,
                                        diagnostic,
                                        expression,
                                        typeSymbol,
                                        CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue);
                                }
                            }
                        }
                    }

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddArgumentList))
                    {
                        ExpressionSyntax expression = argument.Expression;

                        if (expression.IsKind(
                                SyntaxKind.IdentifierName,
                                SyntaxKind.GenericName,
                                SyntaxKind.SimpleMemberAccessExpression))
                        {
                            InvocationExpressionSyntax invocationExpression = InvocationExpression(
                                expression.WithoutTrailingTrivia(),
                                ArgumentList().WithTrailingTrivia(expression.GetTrailingTrivia()));

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

                            if (semanticModel.GetSpeculativeMethodSymbol(expression.SpanStart, invocationExpression) != null)
                            {
                                CodeAction codeAction = CodeAction.Create(
                                    "Add argument list",
                                    cancellationToken =>
                                    {
                                        ArgumentSyntax newNode = argument.WithExpression(invocationExpression);

                                        return(context.Document.ReplaceNodeAsync(argument, newNode, cancellationToken));
                                    },
                                    GetEquivalenceKey(diagnostic, CodeFixIdentifiers.AddArgumentList));

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

                    if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.CreateSingletonArray))
                    {
                        ExpressionSyntax expression = argument.Expression;

                        if (expression?.IsMissing == false)
                        {
                            SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);

                            ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(expression);

                            if (typeSymbol?.IsErrorType() == false)
                            {
                                foreach (ITypeSymbol typeSymbol2 in DetermineParameterTypeHelper.DetermineParameterTypes(argument, semanticModel, context.CancellationToken))
                                {
                                    if (!typeSymbol.Equals(typeSymbol2) &&
                                        typeSymbol2 is IArrayTypeSymbol arrayType &&
                                        semanticModel.IsImplicitConversion(expression, arrayType.ElementType))
                                    {
                                        CodeAction codeAction = CodeAction.Create(
                                            "Create singleton array",
                                            cancellationToken => CreateSingletonArrayRefactoring.RefactorAsync(context.Document, expression, arrayType.ElementType, semanticModel, cancellationToken),
                                            GetEquivalenceKey(diagnostic, CodeFixIdentifiers.CreateSingletonArray));

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

                    break;
                }

                case CompilerDiagnosticIdentifiers.ReadOnlyFieldCannotBePassedAsRefOrOutValue:
                {
                    if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.MakeFieldWritable))
                    {
                        return;
                    }

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

                    SymbolInfo symbolInfo = semanticModel.GetSymbolInfo(argument.Expression, context.CancellationToken);

                    if (symbolInfo.CandidateReason != CandidateReason.NotAVariable)
                    {
                        return;
                    }

                    if (!(symbolInfo.CandidateSymbols.SingleOrDefault(shouldThrow: false) is IFieldSymbol fieldSymbol))
                    {
                        return;
                    }

                    if (fieldSymbol.DeclaredAccessibility != Accessibility.Private)
                    {
                        return;
                    }

                    if (!(fieldSymbol.GetSyntax().Parent.Parent is FieldDeclarationSyntax fieldDeclaration))
                    {
                        return;
                    }

                    TypeDeclarationSyntax containingTypeDeclaration = fieldDeclaration.FirstAncestor <TypeDeclarationSyntax>();

                    if (!argument.Ancestors().Any(f => f == containingTypeDeclaration))
                    {
                        return;
                    }

                    ModifiersCodeFixRegistrator.RemoveModifier(
                        context,
                        diagnostic,
                        fieldDeclaration,
                        SyntaxKind.ReadOnlyKeyword,
                        title: $"Make '{fieldSymbol.Name}' writable",
                        additionalKey: CodeFixIdentifiers.MakeFieldWritable);

                    break;
                }
                }
            }
        }