private static Task <Document> SimplifyDefaultExpressionAsync(
Document document,
DefaultExpressionSyntax defaultExpression,
CancellationToken cancellationToken)
{
LiteralExpressionSyntax defaultLiteral = CSharpFactory.DefaultLiteralExpression().WithTrailingTrivia(defaultExpression.GetTrailingTrivia());
return(document.ReplaceNodeAsync(defaultExpression, defaultLiteral, cancellationToken));
}
public override SyntaxNode VisitDefaultExpression(DefaultExpressionSyntax node)
{
if (Options.UseDefaultLiteral)
{
Debug.Assert(node.IsParentKind(SyntaxKind.EqualsValueClause) &&
node.Parent.IsParentKind(SyntaxKind.Parameter), node.ToString());
if (node.IsParentKind(SyntaxKind.EqualsValueClause) &&
node.Parent.IsParentKind(SyntaxKind.Parameter))
{
return(CSharpFactory.DefaultLiteralExpression());
}
}
return(base.VisitDefaultExpression(node));
}
public override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);
if (!TryFindFirstAncestorOrSelf(root, context.Span, out IdentifierNameSyntax identifierName))
{
return;
}
Document document = context.Document;
CancellationToken cancellationToken = context.CancellationToken;
foreach (Diagnostic diagnostic in context.Diagnostics)
{
switch (diagnostic.Id)
{
case CompilerDiagnosticIdentifiers.UseOfUnassignedLocalVariable:
{
if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.InitializeLocalVariableWithDefaultValue))
{
return;
}
SemanticModel semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
if (!(semanticModel.GetSymbol(identifierName, cancellationToken) is ILocalSymbol localSymbol))
{
break;
}
ITypeSymbol typeSymbol = localSymbol.Type;
if (typeSymbol.Kind == SymbolKind.ErrorType)
{
break;
}
if (!(localSymbol.GetSyntax(cancellationToken) is VariableDeclaratorSyntax variableDeclarator))
{
break;
}
CodeAction codeAction = CodeAction.Create(
$"Initialize '{identifierName.Identifier.ValueText}' with default value",
ct =>
{
SyntaxToken identifier = variableDeclarator.Identifier;
var variableDeclaration = (VariableDeclarationSyntax)variableDeclarator.Parent;
ExpressionSyntax value = typeSymbol.GetDefaultValueSyntax(variableDeclaration.Type.WithoutTrivia(), document.GetDefaultSyntaxOptions());
if (value.IsKind(SyntaxKind.DefaultExpression) &&
document.SupportsLanguageFeature(CSharpLanguageFeature.DefaultLiteral))
{
value = CSharpFactory.DefaultLiteralExpression().WithTriviaFrom(value);
}
EqualsValueClauseSyntax newEqualsValue = EqualsValueClause(value)
.WithLeadingTrivia(TriviaList(Space))
.WithTrailingTrivia(identifier.TrailingTrivia);
VariableDeclaratorSyntax newNode = variableDeclarator
.WithInitializer(newEqualsValue)
.WithIdentifier(identifier.WithoutTrailingTrivia());
return(document.ReplaceNodeAsync(variableDeclarator, newNode, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case CompilerDiagnosticIdentifiers.NameDoesNotExistInCurrentContext:
{
if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddVariableType))
{
return;
}
if (!(identifierName.Parent is ArgumentSyntax argument))
{
break;
}
if (argument.RefOrOutKeyword.Kind() != SyntaxKind.OutKeyword)
{
break;
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
foreach (ITypeSymbol typeSymbol in DetermineParameterTypeHelper.DetermineParameterTypes(argument, semanticModel, cancellationToken))
{
if (typeSymbol.Kind == SymbolKind.TypeParameter)
{
continue;
}
string typeName = SymbolDisplay.ToMinimalDisplayString(typeSymbol, semanticModel, identifierName.SpanStart, SymbolDisplayFormats.DisplayName);
CodeAction codeAction = CodeAction.Create(
$"Add variable type '{typeName}'",
ct =>
{
DeclarationExpressionSyntax newNode = DeclarationExpression(
typeSymbol.ToTypeSyntax(),
SingleVariableDesignation(identifierName.Identifier.WithoutTrivia()).WithLeadingTrivia(Space));
newNode = newNode
.WithTriviaFrom(identifierName)
.WithFormatterAnnotation();
return(document.ReplaceNodeAsync(identifierName, newNode, ct));
},
GetEquivalenceKey(diagnostic, typeName));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
break;
}
}
}
}
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;
}
SyntaxKind kind = token.Kind();
foreach (Diagnostic diagnostic in context.Diagnostics)
{
switch (diagnostic.Id)
{
case CompilerDiagnosticIdentifiers.OperatorCannotBeAppliedToOperand:
{
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.IsNullableType())
{
if (typeSymbol.IsValueType)
{
if (Settings.IsEnabled(diagnostic.Id, 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.IsEnabled(diagnostic.Id, 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);
}
}
}
}
break;
}
case CompilerDiagnosticIdentifiers.PartialModifierCanOnlyAppearImmediatelyBeforeClassStructInterfaceOrVoid:
{
if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.OrderModifiers))
{
break;
}
ModifiersCodeFixRegistrator.MoveModifier(context, diagnostic, token.Parent, token);
break;
}
case CompilerDiagnosticIdentifiers.ValueCannotBeUsedAsDefaultParameter:
{
if (!(token.Parent is ParameterSyntax parameter))
{
break;
}
ExpressionSyntax value = parameter.Default?.Value;
if (value == null)
{
break;
}
if (value.IsKind(SyntaxKind.NullLiteralExpression))
{
if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue))
{
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
CodeFixRegistrator.ReplaceNullWithDefaultValue(context, diagnostic, value, semanticModel);
}
}
else if (!value.IsKind(SyntaxKind.DefaultExpression, SyntaxKind.DefaultLiteralExpression))
{
if (Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeParameterType))
{
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(value, context.CancellationToken);
if (!typeSymbol.IsKind(SymbolKind.ErrorType))
{
CodeFixRegistrator.ChangeType(context, diagnostic, parameter.Type, typeSymbol, semanticModel);
}
}
}
break;
}
case CompilerDiagnosticIdentifiers.ObjectOfTypeConvertibleToTypeIsRequired:
{
if (!Settings.IsEnabled(diagnostic.Id, 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.GetDefaultValueSyntax(context.Document.GetDefaultSyntaxOptions());
if (expression.IsKind(SyntaxKind.DefaultExpression) &&
context.Document.SupportsLanguageFeature(CSharpLanguageFeature.DefaultLiteral))
{
expression = CSharpFactory.DefaultLiteralExpression().WithTriviaFrom(expression);
}
ReturnStatementSyntax newNode = returnStatement.WithExpression(expression);
return(context.Document.ReplaceNodeAsync(returnStatement, newNode, cancellationToken));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case CompilerDiagnosticIdentifiers.TypeExpected:
{
if (!Settings.IsEnabled(diagnostic.Id, 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.ToMinimalDisplayString(convertedType, semanticModel, defaultExpression.SpanStart, SymbolDisplayFormats.Default)}'",
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.IsEnabled(diagnostic.Id, 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.IsEnabled(diagnostic.Id, 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;
}
case CompilerDiagnosticIdentifiers.OptionalParametersMustAppearAfterAllRequiredParameters:
{
if (!Settings.IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddDefaultValueToParameter))
{
break;
}
if (!(token.Parent is BaseParameterListSyntax parameterList))
{
break;
}
SeparatedSyntaxList <ParameterSyntax> parameters = parameterList.Parameters;
ParameterSyntax parameter = null;
for (int i = 0; i < parameters.Count; i++)
{
ParameterSyntax p = parameters[i];
if (p.FullSpan.End <= token.SpanStart)
{
parameter = p;
}
else
{
break;
}
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
IParameterSymbol parameterSymbol = semanticModel.GetDeclaredSymbol(parameter, context.CancellationToken);
ITypeSymbol typeSymbol = parameterSymbol.Type;
if (typeSymbol.Kind == SymbolKind.ErrorType)
{
break;
}
CodeAction codeAction = CodeAction.Create(
"Add default value",
cancellationToken =>
{
ExpressionSyntax defaultValue = typeSymbol.GetDefaultValueSyntax(context.Document.GetDefaultSyntaxOptions());
ParameterSyntax newParameter = parameter
.WithDefault(EqualsValueClause(defaultValue).WithTrailingTrivia(parameter.GetTrailingTrivia()))
.WithoutTrailingTrivia()
.WithFormatterAnnotation();
return(context.Document.ReplaceNodeAsync(parameter, newParameter, cancellationToken));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
}
}
}
public override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);
if (!TryFindToken(root, context.Span.Start, out SyntaxToken token))
{
return;
}
SyntaxKind kind = token.Kind();
Diagnostic diagnostic = context.Diagnostics[0];
Document document = context.Document;
switch (diagnostic.Id)
{
case CompilerDiagnosticIdentifiers.CS0023_OperatorCannotBeAppliedToOperand:
{
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.IsNullableType())
{
if (typeSymbol.IsValueType)
{
if (IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveConditionalAccess, document, root.SyntaxTree))
{
CodeAction codeAction = CodeAction.Create(
"Remove '?' operator",
ct => document.WithTextChangeAsync(token.Span, "", ct),
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
}
else if (typeSymbol.IsReferenceType)
{
if (IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddArgumentList, document, root.SyntaxTree) &&
conditionalAccess.WhenNotNull is MemberBindingExpressionSyntax memberBindingExpression)
{
ConditionalAccessExpressionSyntax newNode = conditionalAccess.WithWhenNotNull(
InvocationExpression(
memberBindingExpression.WithoutTrailingTrivia(),
ArgumentList().WithTrailingTrivia(memberBindingExpression.GetTrailingTrivia())));
CodeAction codeAction = CodeAction.Create(
"Add argument list",
ct => document.ReplaceNodeAsync(conditionalAccess, newNode, ct),
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
}
}
}
break;
}
case CompilerDiagnosticIdentifiers.CS0267_PartialModifierCanOnlyAppearImmediatelyBeforeClassStructInterfaceOrVoid:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.OrderModifiers, document, root.SyntaxTree))
{
break;
}
ModifiersCodeFixRegistrator.MoveModifier(context, diagnostic, token.Parent, token);
break;
}
case CompilerDiagnosticIdentifiers.CS1750_ValueCannotBeUsedAsDefaultParameter:
{
if (token.Parent is not ParameterSyntax parameter)
{
break;
}
ExpressionSyntax value = parameter.Default?.Value;
if (value == null)
{
break;
}
if (value.IsKind(SyntaxKind.NullLiteralExpression))
{
if (IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue, document, root.SyntaxTree))
{
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
CodeFixRegistrator.ReplaceNullWithDefaultValue(context, diagnostic, value, semanticModel);
}
}
else if (!value.IsKind(SyntaxKind.DefaultExpression, SyntaxKind.DefaultLiteralExpression))
{
if (IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeParameterType, document, root.SyntaxTree))
{
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(value, context.CancellationToken);
if (!typeSymbol.IsKind(SymbolKind.ErrorType))
{
CodeFixRegistrator.ChangeType(context, diagnostic, parameter.Type, typeSymbol, semanticModel);
}
}
}
break;
}
case CompilerDiagnosticIdentifiers.CS0126_ObjectOfTypeConvertibleToTypeIsRequired:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReturnDefaultValue, document, root.SyntaxTree))
{
break;
}
if (!token.IsKind(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",
ct =>
{
ExpressionSyntax expression = typeSymbol.GetDefaultValueSyntax(document.GetDefaultSyntaxOptions());
if (expression.IsKind(SyntaxKind.DefaultExpression) &&
document.SupportsLanguageFeature(CSharpLanguageFeature.DefaultLiteral))
{
expression = CSharpFactory.DefaultLiteralExpression().WithTriviaFrom(expression);
}
ReturnStatementSyntax newNode = returnStatement.WithExpression(expression);
return(document.ReplaceNodeAsync(returnStatement, newNode, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case CompilerDiagnosticIdentifiers.CS1031_TypeExpected:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddMissingType, document, root.SyntaxTree))
{
break;
}
if (!token.IsKind(SyntaxKind.CloseParenToken))
{
break;
}
if (token.Parent is not DefaultExpressionSyntax defaultExpression)
{
break;
}
if (defaultExpression.Type is not 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.ToMinimalDisplayString(convertedType, semanticModel, defaultExpression.SpanStart, SymbolDisplayFormats.DisplayName)}'",
ct =>
{
TypeSyntax newType = convertedType.ToTypeSyntax()
.WithTriviaFrom(identifierName)
.WithFormatterAndSimplifierAnnotation();
return(document.ReplaceNodeAsync(identifierName, newType, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case CompilerDiagnosticIdentifiers.CS1597_SemicolonAfterMethodOrAccessorBlockIsNotValid:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveSemicolon, document, root.SyntaxTree))
{
break;
}
if (!token.IsKind(SyntaxKind.SemicolonToken))
{
break;
}
switch (token.Parent)
{
case MethodDeclarationSyntax methodDeclaration:
{
BlockSyntax body = methodDeclaration.Body;
if (body == null)
{
break;
}
CodeAction codeAction = CodeAction.Create(
"Remove semicolon",
ct =>
{
SyntaxTriviaList trivia = body
.GetTrailingTrivia()
.EmptyIfWhitespace()
.AddRange(token.LeadingTrivia.EmptyIfWhitespace())
.AddRange(token.TrailingTrivia);
MethodDeclarationSyntax newNode = methodDeclaration
.WithBody(body.WithTrailingTrivia(trivia))
.WithSemicolonToken(default(SyntaxToken));
return(document.ReplaceNodeAsync(methodDeclaration, newNode, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case PropertyDeclarationSyntax propertyDeclaration:
{
AccessorListSyntax accessorList = propertyDeclaration.AccessorList;
if (accessorList == null)
{
break;
}
CodeAction codeAction = CodeAction.Create(
"Remove semicolon",
ct =>
{
SyntaxTriviaList trivia = accessorList
.GetTrailingTrivia()
.EmptyIfWhitespace()
.AddRange(token.LeadingTrivia.EmptyIfWhitespace())
.AddRange(token.TrailingTrivia);
PropertyDeclarationSyntax newNode = propertyDeclaration
.WithAccessorList(accessorList.WithTrailingTrivia(trivia))
.WithSemicolonToken(default(SyntaxToken));
return(document.ReplaceNodeAsync(propertyDeclaration, newNode, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case AccessorDeclarationSyntax accessorDeclaration:
{
BlockSyntax body = accessorDeclaration.Body;
if (body == null)
{
break;
}
CodeAction codeAction = CodeAction.Create(
"Remove semicolon",
ct =>
{
SyntaxTriviaList trivia = body
.GetTrailingTrivia()
.EmptyIfWhitespace()
.AddRange(token.LeadingTrivia.EmptyIfWhitespace())
.AddRange(token.TrailingTrivia);
AccessorDeclarationSyntax newNode = accessorDeclaration
.WithBody(body.WithTrailingTrivia(trivia))
.WithSemicolonToken(default(SyntaxToken));
return(document.ReplaceNodeAsync(accessorDeclaration, newNode, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
}
break;
}
case CompilerDiagnosticIdentifiers.CS0030_CannotConvertType:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.ChangeForEachType, document, root.SyntaxTree))
{
break;
}
if (!token.IsKind(SyntaxKind.ForEachKeyword))
{
break;
}
if (token.Parent is not 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;
}
case CompilerDiagnosticIdentifiers.CS1737_OptionalParametersMustAppearAfterAllRequiredParameters:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddDefaultValueToParameter, document, root.SyntaxTree))
{
break;
}
if (token.Parent is not BaseParameterListSyntax parameterList)
{
break;
}
SeparatedSyntaxList <ParameterSyntax> parameters = parameterList.Parameters;
ParameterSyntax parameter = null;
for (int i = 0; i < parameters.Count; i++)
{
ParameterSyntax p = parameters[i];
if (p.FullSpan.End <= token.SpanStart)
{
parameter = p;
}
else
{
break;
}
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
IParameterSymbol parameterSymbol = semanticModel.GetDeclaredSymbol(parameter, context.CancellationToken);
ITypeSymbol typeSymbol = parameterSymbol.Type;
if (typeSymbol.Kind == SymbolKind.ErrorType)
{
break;
}
CodeAction codeAction = CodeAction.Create(
"Add default value",
ct =>
{
ExpressionSyntax defaultValue = typeSymbol.GetDefaultValueSyntax(document.GetDefaultSyntaxOptions());
ParameterSyntax newParameter = parameter
.WithDefault(EqualsValueClause(defaultValue).WithTrailingTrivia(parameter.GetTrailingTrivia()))
.WithoutTrailingTrivia()
.WithFormatterAnnotation();
return(document.ReplaceNodeAsync(parameter, newParameter, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case CompilerDiagnosticIdentifiers.CS8632_AnnotationForNullableReferenceTypesShouldOnlyBeUsedWithinNullableAnnotationsContext:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveAnnotationForNullableReferenceTypes, document, root.SyntaxTree))
{
break;
}
if (!token.IsKind(SyntaxKind.QuestionToken))
{
return;
}
CodeAction codeAction = CodeAction.Create(
"Remove 'nullable' annotation",
ct =>
{
var textChange = new TextChange(token.Span, "");
return(document.WithTextChangeAsync(textChange, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case CompilerDiagnosticIdentifiers.CS8602_DereferenceOfPossiblyNullReference:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.UseNullForgivingOperator, document, root.SyntaxTree))
{
break;
}
Debug.Assert(token.IsKind(SyntaxKind.IdentifierToken), token.Kind().ToString());
if (!token.IsKind(SyntaxKind.IdentifierToken))
{
return;
}
if (!token.IsParentKind(SyntaxKind.IdentifierName))
{
return;
}
SyntaxNode node = token.Parent
.WalkUp(f => f.IsKind(SyntaxKind.SimpleMemberAccessExpression, SyntaxKind.InvocationExpression, SyntaxKind.ElementAccessExpression))
.Parent;
if (node.IsKind(SyntaxKind.ExpressionStatement) &&
token.SpanStart == node.SpanStart)
{
CodeAction codeAction = CodeAction.Create(
"Use null propagation operator",
ct =>
{
var textChange = new TextChange(new TextSpan(token.Span.End, 0), "?");
return(document.WithTextChangeAsync(textChange, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
return;
}
case CompilerDiagnosticIdentifiers.CS8604_PossibleNullReferenceArgumentForParameter:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.UseNullForgivingOperator, document, root.SyntaxTree))
{
break;
}
Debug.Assert(token.IsKind(SyntaxKind.IdentifierToken), token.Kind().ToString());
if (!token.IsKind(SyntaxKind.IdentifierToken))
{
return;
}
if (!token.IsParentKind(SyntaxKind.IdentifierName))
{
return;
}
CodeAction codeAction = CodeAction.Create(
"Use null-forgiving operator",
ct =>
{
var identifierName = (IdentifierNameSyntax)token.Parent;
PostfixUnaryExpressionSyntax newExpression = SuppressNullableWarningExpression(identifierName.WithoutTrivia())
.WithTriviaFrom(identifierName);
return(document.ReplaceNodeAsync(identifierName, newExpression, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
return;
}
case CompilerDiagnosticIdentifiers.CS8618_NonNullableMemberIsUninitialized:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.UseNullForgivingOperator, document, root.SyntaxTree))
{
break;
}
Debug.Assert(token.IsKind(SyntaxKind.IdentifierToken), token.Kind().ToString());
if (!token.IsKind(SyntaxKind.IdentifierToken))
{
return;
}
if (token.IsParentKind(SyntaxKind.PropertyDeclaration))
{
CodeAction codeAction = CodeAction.Create(
"Use null-forgiving operator",
ct =>
{
var property = (PropertyDeclarationSyntax)token.Parent;
PropertyDeclarationSyntax newProperty = property
.WithoutTrailingTrivia()
.WithInitializer(EqualsValueClause(SuppressNullableWarningExpression(NullLiteralExpression())))
.WithSemicolonToken(SemicolonToken().WithTrailingTrivia(property.GetTrailingTrivia()));
return(document.ReplaceNodeAsync(property, newProperty, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
else
{
SyntaxDebug.Assert(
(token.IsParentKind(SyntaxKind.VariableDeclarator) &&
token.Parent.IsParentKind(SyntaxKind.VariableDeclaration) &&
token.Parent.Parent.IsParentKind(SyntaxKind.FieldDeclaration, SyntaxKind.EventFieldDeclaration)) ||
token.IsParentKind(SyntaxKind.ConstructorDeclaration),
token);
if (token.IsParentKind(SyntaxKind.VariableDeclarator) &&
token.Parent.IsParentKind(SyntaxKind.VariableDeclaration) &&
token.Parent.Parent.IsParentKind(SyntaxKind.FieldDeclaration))
{
CodeAction codeAction = CodeAction.Create(
"Use null-forgiving operator",
ct =>
{
var declarator = (VariableDeclaratorSyntax)token.Parent;
VariableDeclaratorSyntax newDeclarator = declarator
.WithoutTrailingTrivia()
.WithInitializer(
EqualsValueClause(SuppressNullableWarningExpression(NullLiteralExpression()))
.WithTrailingTrivia(declarator.GetTrailingTrivia()));
return(document.ReplaceNodeAsync(declarator, newDeclarator, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
}
break;
}
case CompilerDiagnosticIdentifiers.CS8403_MethodWithIteratorBlockMustBeAsyncToReturnIAsyncEnumerableOfT:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.AddAsyncModifier, document, root.SyntaxTree))
{
break;
}
SyntaxDebug.Assert(token.IsKind(SyntaxKind.IdentifierToken), token);
SyntaxDebug.Assert(token.IsParentKind(SyntaxKind.MethodDeclaration, SyntaxKind.LocalFunctionStatement), token.Parent);
if (token.IsParentKind(SyntaxKind.MethodDeclaration, SyntaxKind.LocalFunctionStatement))
{
ModifiersCodeFixRegistrator.AddModifier(
context,
diagnostic,
token.Parent,
SyntaxKind.AsyncKeyword,
additionalKey: CodeFixIdentifiers.AddAsyncModifier);
}
break;
}
}
}