private void ComputeCodeFix(
CodeFixContext context,
Diagnostic diagnostic,
VariableDeclaratorSyntax variableDeclarator,
ISymbol symbol,
SemanticModel semanticModel)
{
if (symbol is IMethodSymbol methodSymbol)
{
ImmutableArray <IParameterSymbol> parameters = methodSymbol.Parameters;
if (parameters.Length <= 16)
{
ITypeSymbol returnType = methodSymbol.ReturnType;
if (SupportsExplicitDeclaration(returnType, parameters))
{
INamedTypeSymbol typeSymbol = ConstructActionOrFunc(returnType, parameters, semanticModel);
var variableDeclaration = (VariableDeclarationSyntax)variableDeclarator.Parent;
CodeAction codeAction = CodeActionFactory.ChangeType(
context.Document,
variableDeclaration.Type,
typeSymbol,
semanticModel,
equivalenceKey: GetEquivalenceKey(diagnostic, SymbolDisplay.ToDisplayString(typeSymbol)));
context.RegisterCodeFix(codeAction, diagnostic);
}
}
}
}
internal static async Task ChangeTypeAsync(
RefactoringContext context,
ForEachStatementSyntax forEachStatement)
{
TypeSyntax type = forEachStatement.Type;
if (type?.Span.Contains(context.Span) != true)
{
return;
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
TypeAnalysis analysis = CSharpTypeAnalysis.AnalyzeType(forEachStatement, semanticModel);
if (analysis.IsExplicit)
{
if (analysis.SupportsImplicit &&
context.IsRefactoringEnabled(RefactoringIdentifiers.ChangeExplicitTypeToVar))
{
context.RegisterRefactoring(CodeActionFactory.ChangeTypeToVar(context.Document, type, equivalenceKey: RefactoringIdentifiers.ChangeExplicitTypeToVar));
}
if (!forEachStatement.ContainsDiagnostics &&
context.IsRefactoringEnabled(RefactoringIdentifiers.ChangeTypeAccordingToExpression))
{
ChangeTypeAccordingToExpression(context, forEachStatement, semanticModel);
}
}
else if (analysis.SupportsExplicit &&
context.IsRefactoringEnabled(RefactoringIdentifiers.ChangeVarToExplicitType))
{
context.RegisterRefactoring(CodeActionFactory.ChangeType(context.Document, type, analysis.Symbol, semanticModel, equivalenceKey: RefactoringIdentifiers.ChangeVarToExplicitType));
}
}
private static void ChangeTypeAccordingToExpression(
RefactoringContext context,
ForEachStatementSyntax forEachStatement,
SemanticModel semanticModel)
{
ForEachStatementInfo info = semanticModel.GetForEachStatementInfo(forEachStatement);
ITypeSymbol elementType = info.ElementType;
if (elementType?.IsErrorType() != false)
{
return;
}
Conversion conversion = info.ElementConversion;
if (conversion.IsIdentity)
{
return;
}
if (!conversion.IsImplicit)
{
return;
}
context.RegisterRefactoring(CodeActionFactory.ChangeType(context.Document, forEachStatement.Type, elementType, semanticModel, equivalenceKey: RefactoringIdentifiers.ChangeTypeAccordingToExpression));
}
public static async Task ComputeRefactoringsAsync(
RefactoringContext context,
DeclarationExpressionSyntax declarationExpression)
{
if (declarationExpression.Type?.Span.Contains(context.Span) == true &&
context.IsAnyRefactoringEnabled(
RefactoringIdentifiers.ChangeExplicitTypeToVar,
RefactoringIdentifiers.ChangeVarToExplicitType))
{
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
TypeAnalysis analysis = CSharpTypeAnalysis.AnalyzeType(declarationExpression, semanticModel, context.CancellationToken);
if (analysis.IsExplicit)
{
if (analysis.SupportsImplicit &&
context.IsRefactoringEnabled(RefactoringIdentifiers.ChangeExplicitTypeToVar))
{
context.RegisterRefactoring(CodeActionFactory.ChangeTypeToVar(context.Document, declarationExpression.Type, equivalenceKey: RefactoringIdentifiers.ChangeExplicitTypeToVar));
}
}
else if (analysis.SupportsExplicit &&
context.IsRefactoringEnabled(RefactoringIdentifiers.ChangeVarToExplicitType))
{
TypeSyntax type = declarationExpression.Type;
var localSymbol = (ILocalSymbol)semanticModel.GetDeclaredSymbol(declarationExpression.Designation, context.CancellationToken);
ITypeSymbol typeSymbol = localSymbol.Type;
context.RegisterRefactoring(CodeActionFactory.ChangeType(context.Document, type, typeSymbol, semanticModel, equivalenceKey: RefactoringIdentifiers.ChangeVarToExplicitType));
}
}
}
public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);
if (!TryFindFirstAncestorOrSelf(
root,
context.Span,
out SyntaxNode node,
predicate: f => f.IsKind(SyntaxKind.ForEachStatement, SyntaxKind.ForEachVariableStatement, SyntaxKind.DeclarationExpression)))
{
return;
}
Document document = context.Document;
Diagnostic diagnostic = context.Diagnostics[0];
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
TypeSyntax type;
ITypeSymbol typeSymbol;
switch (node)
{
case ForEachStatementSyntax forEachStatement:
{
type = forEachStatement.Type;
typeSymbol = semanticModel.GetTypeSymbol(type, context.CancellationToken);
break;
}
case ForEachVariableStatementSyntax forEachVariableStatement:
{
var declarationExpression = (DeclarationExpressionSyntax)forEachVariableStatement.Variable;
type = declarationExpression.Type;
typeSymbol = semanticModel.GetTypeSymbol(declarationExpression, context.CancellationToken);
break;
}
case DeclarationExpressionSyntax declarationExpression:
{
type = declarationExpression.Type;
typeSymbol = semanticModel.GetTypeSymbol(declarationExpression, context.CancellationToken);
break;
}
default:
{
throw new InvalidOperationException();
}
}
CodeAction codeAction = CodeActionFactory.ChangeType(document, type, typeSymbol, semanticModel, equivalenceKey: GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
private void RegisterCodeFix(CodeFixContext context, TypeSyntax type, ITypeSymbol typeSymbol, SemanticModel semanticModel)
{
foreach (Diagnostic diagnostic in context.Diagnostics)
{
CodeAction codeAction = CodeActionFactory.ChangeType(context.Document, type, typeSymbol, semanticModel, equivalenceKey: GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
}
public static CodeFixRegistrationResult ChangeType(
CodeFixContext context,
Diagnostic diagnostic,
TypeSyntax type,
ITypeSymbol newTypeSymbol,
SemanticModel semanticModel,
string additionalKey = null)
{
CodeAction codeAction = CodeActionFactory.ChangeType(context.Document, type, newTypeSymbol, semanticModel, equivalenceKey: EquivalenceKey.Create(diagnostic, additionalKey));
context.RegisterCodeFix(codeAction, diagnostic);
return(new CodeFixRegistrationResult(true));
}
public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);
if (!TryFindFirstAncestorOrSelf(root, context.Span, out ForEachStatementSyntax forEachStatement))
{
return;
}
Diagnostic diagnostic = context.Diagnostics[0];
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
TypeSyntax type = forEachStatement.Type;
ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(type, context.CancellationToken);
CodeAction codeAction = CodeActionFactory.ChangeType(context.Document, type, typeSymbol, semanticModel, equivalenceKey: GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
private static void ChangeTypeAccordingToExpression(
RefactoringContext context,
VariableDeclarationSyntax variableDeclaration,
ITypeSymbol typeSymbol,
SemanticModel semanticModel)
{
foreach (VariableDeclaratorSyntax variableDeclarator in variableDeclaration.Variables)
{
ExpressionSyntax value = variableDeclarator.Initializer?.Value;
if (value == null)
{
return;
}
Conversion conversion = semanticModel.ClassifyConversion(value, typeSymbol);
if (conversion.IsIdentity)
{
return;
}
if (!conversion.IsImplicit)
{
return;
}
}
ITypeSymbol newTypeSymbol = semanticModel.GetTypeSymbol(variableDeclaration.Variables[0].Initializer.Value, context.CancellationToken);
if (newTypeSymbol == null)
{
return;
}
context.RegisterRefactoring(CodeActionFactory.ChangeType(context.Document, variableDeclaration.Type, newTypeSymbol, semanticModel, equivalenceKey: RefactoringIdentifiers.ChangeTypeAccordingToExpression));
}
public static void ChangeTypeOrReturnType(
CodeFixContext context,
Diagnostic diagnostic,
SyntaxNode node,
ITypeSymbol newTypeSymbol,
SemanticModel semanticModel,
string additionalKey = null)
{
if (newTypeSymbol.IsErrorType())
{
return;
}
TypeSyntax type = CSharpUtility.GetTypeOrReturnType(node);
if (type == null)
{
return;
}
CodeAction codeAction = CodeActionFactory.ChangeType(context.Document, type, newTypeSymbol, semanticModel, equivalenceKey: EquivalenceKey.Create(diagnostic, additionalKey));
context.RegisterCodeFix(codeAction, diagnostic);
}
public override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);
if (!TryFindFirstAncestorOrSelf(
root,
context.Span,
out SyntaxNode node,
predicate: f => f.IsKind(
SyntaxKind.VariableDeclaration,
SyntaxKind.ForEachStatement,
SyntaxKind.Parameter,
SyntaxKind.DeclarationPattern,
SyntaxKind.DeclarationExpression,
SyntaxKind.LocalFunctionStatement)))
{
return;
}
if (node.IsKind(SyntaxKind.ForEachStatement, SyntaxKind.Parameter, SyntaxKind.DeclarationPattern, SyntaxKind.DeclarationExpression, SyntaxKind.LocalFunctionStatement))
{
return;
}
var variableDeclaration = (VariableDeclarationSyntax)node;
foreach (Diagnostic diagnostic in context.Diagnostics)
{
switch (diagnostic.Id)
{
case CompilerDiagnosticIdentifiers.CS0819_ImplicitlyTypedVariablesCannotHaveMultipleDeclarators:
case CompilerDiagnosticIdentifiers.CS0822_ImplicitlyTypedVariablesCannotBeConstant:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.UseExplicitTypeInsteadOfVar, context.Document, root.SyntaxTree))
{
return;
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
TypeSyntax type = variableDeclaration.Type;
ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(type, context.CancellationToken);
if (typeSymbol?.SupportsExplicitDeclaration() == true)
{
CodeAction codeAction = CodeActionFactory.ChangeType(context.Document, type, typeSymbol, semanticModel, equivalenceKey: GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
break;
}
case CompilerDiagnosticIdentifiers.CS0128_LocalVariableOrFunctionIsAlreadyDefinedInThisScope:
case CompilerDiagnosticIdentifiers.CS0136_LocalOrParameterCannotBeDeclaredInThisScopeBecauseThatNameIsUsedInEnclosingScopeToDefineLocalOrParameter:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.ReplaceVariableDeclarationWithAssignment, context.Document, root.SyntaxTree))
{
return;
}
if (variableDeclaration.Parent is not LocalDeclarationStatementSyntax localDeclaration)
{
return;
}
VariableDeclaratorSyntax variableDeclarator = variableDeclaration.Variables.SingleOrDefault(shouldThrow: false);
if (variableDeclarator == null)
{
break;
}
ExpressionSyntax value = variableDeclarator.Initializer?.Value;
if (value == null)
{
break;
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
VariableDeclaratorSyntax variableDeclarator2 = FindVariableDeclarator(
variableDeclarator.Identifier.ValueText,
semanticModel.GetEnclosingSymbolSyntax(localDeclaration.SpanStart, context.CancellationToken));
if (variableDeclarator2?.SpanStart < localDeclaration.SpanStart)
{
CodeAction codeAction = CodeAction.Create(
"Replace variable declaration with assignment",
ct =>
{
ExpressionStatementSyntax newNode = CSharpFactory.SimpleAssignmentStatement(
SyntaxFactory.IdentifierName(variableDeclarator.Identifier),
value);
newNode = newNode
.WithTriviaFrom(localDeclaration)
.WithFormatterAnnotation();
return(context.Document.ReplaceNodeAsync(localDeclaration, newNode, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
break;
}
}
}
}
public static async Task ComputeRefactoringsAsync(RefactoringContext context, VariableDeclarationSyntax variableDeclaration)
{
TypeSyntax type = variableDeclaration.Type;
if (type?.Span.Contains(context.Span) == true &&
context.IsAnyRefactoringEnabled(
RefactoringIdentifiers.ChangeExplicitTypeToVar,
RefactoringIdentifiers.ChangeVarToExplicitType,
RefactoringIdentifiers.ChangeTypeAccordingToExpression))
{
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
TypeAnalysis analysis = CSharpTypeAnalysis.AnalyzeType(variableDeclaration, semanticModel, context.CancellationToken);
if (analysis.IsExplicit)
{
if (analysis.SupportsImplicit &&
context.IsRefactoringEnabled(RefactoringIdentifiers.ChangeExplicitTypeToVar))
{
context.RegisterRefactoring(CodeActionFactory.ChangeTypeToVar(context.Document, type, equivalenceKey: RefactoringIdentifiers.ChangeExplicitTypeToVar));
}
if (!variableDeclaration.ContainsDiagnostics &&
context.IsRefactoringEnabled(RefactoringIdentifiers.ChangeTypeAccordingToExpression))
{
ChangeTypeAccordingToExpression(context, variableDeclaration, analysis.Symbol, semanticModel);
}
}
else if (analysis.SupportsExplicit &&
context.IsRefactoringEnabled(RefactoringIdentifiers.ChangeVarToExplicitType))
{
ITypeSymbol typeSymbol = analysis.Symbol;
VariableDeclaratorSyntax variableDeclarator = variableDeclaration.Variables.SingleOrDefault(shouldThrow: false);
if (variableDeclarator?.Initializer?.Value != null)
{
if (typeSymbol.OriginalDefinition.EqualsOrInheritsFromTaskOfT())
{
Func <CancellationToken, Task <Document> > createChangedDocument = DocumentRefactoringFactory.ChangeTypeAndAddAwait(
context.Document,
variableDeclaration,
variableDeclarator,
typeSymbol,
semanticModel,
context.CancellationToken);
if (createChangedDocument != null)
{
ITypeSymbol typeArgument = ((INamedTypeSymbol)typeSymbol).TypeArguments[0];
context.RegisterRefactoring(
$"Change type to '{SymbolDisplay.ToMinimalDisplayString(typeArgument, semanticModel, type.SpanStart)}' and add 'await'",
createChangedDocument,
EquivalenceKey.Join(RefactoringIdentifiers.ChangeVarToExplicitType, "AddAwait"));
}
}
typeSymbol = semanticModel.GetTypeSymbol(variableDeclarator.Initializer.Value, context.CancellationToken);
if (typeSymbol != null)
{
context.RegisterRefactoring(CodeActionFactory.ChangeType(context.Document, type, typeSymbol, semanticModel, equivalenceKey: RefactoringIdentifiers.ChangeVarToExplicitType));
}
}
}
}
}
