public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
if (!Settings.IsAnyCodeFixEnabled(
CodeFixIdentifiers.AddComparisonWithBooleanLiteral,
CodeFixIdentifiers.CreateSingletonArray,
CodeFixIdentifiers.UseUncheckedExpression,
CodeFixIdentifiers.RemoveConstModifier,
CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue))
{
return;
}
SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);
var expression = root.FindNode(context.Span, getInnermostNodeForTie: true) as ExpressionSyntax;
Debug.Assert(expression != null, $"{nameof(expression)} is null");
if (expression == null)
{
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 (Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddComparisonWithBooleanLiteral) &&
type?.IsNullableOf(SpecialType.System_Boolean) == true)
{
if (convertedType?.IsBoolean() == true ||
AddComparisonWithBooleanLiteralRefactoring.IsCondition(expression))
{
CodeAction codeAction = CodeAction.Create(
AddComparisonWithBooleanLiteralRefactoring.GetTitle(expression),
cancellationToken => AddComparisonWithBooleanLiteralRefactoring.RefactorAsync(context.Document, expression, cancellationToken),
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
}
if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.CreateSingletonArray) &&
type?.IsErrorType() == false &&
!type.Equals(convertedType) &&
convertedType.IsArrayType())
{
var arrayType = (IArrayTypeSymbol)convertedType;
if (semanticModel.IsImplicitConversion(expression, arrayType.ElementType))
{
CodeAction codeAction = CodeAction.Create(
"Create singleton array",
cancellationToken => CreateSingletonArrayRefactoring.RefactorAsync(context.Document, expression, arrayType.ElementType, semanticModel, cancellationToken),
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
}
break;
}
case CompilerDiagnosticIdentifiers.ConstantValueCannotBeConverted:
{
if (!Settings.IsCodeFixEnabled(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:
{
if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveConstModifier))
{
break;
}
LocalDeclarationStatementSyntax localDeclarationStatement = GetLocalDeclarationStatement(expression);
if (localDeclarationStatement == null)
{
break;
}
SyntaxTokenList modifiers = localDeclarationStatement.Modifiers;
if (!modifiers.Contains(SyntaxKind.ConstKeyword))
{
break;
}
CodeAction codeAction = CodeAction.Create(
"Remove 'const' modifier",
cancellationToken =>
{
LocalDeclarationStatementSyntax newNode = localDeclarationStatement.RemoveModifier(SyntaxKind.ConstKeyword);
return(context.Document.ReplaceNodeAsync(localDeclarationStatement, newNode, cancellationToken));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case CompilerDiagnosticIdentifiers.CannotConvertNullToTypeBecauseItIsNonNullableValueType:
{
if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue))
{
break;
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
ITypeSymbol typeSymbol = semanticModel.GetTypeInfo(expression, context.CancellationToken).ConvertedType;
if (typeSymbol?.SupportsExplicitDeclaration() == true)
{
CodeAction codeAction = CodeAction.Create(
"Replace 'null' with default value",
cancellationToken =>
{
ExpressionSyntax newNode = typeSymbol.ToDefaultValueSyntax(semanticModel, expression.SpanStart);
return(context.Document.ReplaceNodeAsync(expression, newNode, cancellationToken));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
break;
}
}
}
}
public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.AddComparisonWithBooleanLiteral) &&
!Settings.IsCodeFixEnabled(CodeFixIdentifiers.CreateSingletonArray) &&
!Settings.IsCodeFixEnabled(CodeFixIdentifiers.UseUncheckedExpression) &&
!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveConstModifier) &&
!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue) &&
!Settings.IsCodeFixEnabled(CodeFixIdentifiers.UseCoalesceExpression) &&
!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveConditionThatIsAlwaysEqualToTrueOrFalse))
{
return;
}
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?.IsNamedType() == true)
{
var namedType = (INamedTypeSymbol)type;
if (namedType.ConstructedFrom.SpecialType == SpecialType.System_Nullable_T)
{
if (convertedType?.IsBoolean() == true ||
AddComparisonWithBooleanLiteralRefactoring.IsCondition(expression))
{
if (Settings.IsCodeFixEnabled(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 (namedType.TypeArguments[0].Equals(convertedType))
{
if (Settings.IsCodeFixEnabled(CodeFixIdentifiers.UseCoalesceExpression))
{
CodeAction codeAction = CodeAction.Create(
"Use coalesce expression",
cancellationToken =>
{
ExpressionSyntax defaultValue = convertedType.ToDefaultValueSyntax(semanticModel, expression.SpanStart);
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.IsCodeFixEnabled(CodeFixIdentifiers.CreateSingletonArray) &&
type?.IsErrorType() == false &&
!type.Equals(convertedType) &&
convertedType.IsArrayType())
{
var arrayType = (IArrayTypeSymbol)convertedType;
if (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.IsCodeFixEnabled(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:
{
if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveConstModifier))
{
break;
}
LocalDeclarationStatementSyntax localDeclarationStatement = GetLocalDeclarationStatement(expression);
if (localDeclarationStatement == null)
{
break;
}
SyntaxTokenList modifiers = localDeclarationStatement.Modifiers;
if (!modifiers.Contains(SyntaxKind.ConstKeyword))
{
break;
}
CodeAction codeAction = CodeAction.Create(
"Remove 'const' modifier",
cancellationToken =>
{
LocalDeclarationStatementSyntax newNode = localDeclarationStatement.RemoveModifier(SyntaxKind.ConstKeyword);
return(context.Document.ReplaceNodeAsync(localDeclarationStatement, newNode, cancellationToken));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
case CompilerDiagnosticIdentifiers.CannotConvertNullToTypeBecauseItIsNonNullableValueType:
{
if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.ReplaceNullLiteralExpressionWithDefaultValue))
{
break;
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
ITypeSymbol typeSymbol = semanticModel.GetTypeInfo(expression, context.CancellationToken).ConvertedType;
if (typeSymbol?.SupportsExplicitDeclaration() == true)
{
CodeAction codeAction = CodeAction.Create(
"Replace 'null' with default value",
cancellationToken =>
{
ExpressionSyntax newNode = typeSymbol.ToDefaultValueSyntax(semanticModel, expression.SpanStart);
return(context.Document.ReplaceNodeAsync(expression, newNode, cancellationToken));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
break;
}
case CompilerDiagnosticIdentifiers.ResultOfExpressionIsAlwaysConstantSinceValueIsNeverEqualToNull:
{
if (!Settings.IsCodeFixEnabled(CodeFixIdentifiers.RemoveConditionThatIsAlwaysEqualToTrueOrFalse))
{
break;
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
if (!NullCheckExpression.TryCreate(expression, semanticModel, out NullCheckExpression nullCheck, context.CancellationToken))
{
break;
}
if (nullCheck.Kind != NullCheckKind.EqualsToNull &&
nullCheck.Kind != NullCheckKind.NotEqualsToNull)
{
break;
}
CodeAction codeAction = CodeAction.Create(
"Remove condition",
cancellationToken =>
{
SyntaxNode newRoot = RemoveHelper.RemoveCondition(root, expression, nullCheck.Kind == NullCheckKind.NotEqualsToNull);
return(Task.FromResult(context.Document.WithSyntaxRoot(newRoot)));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
break;
}
}
}
}