public abstract TDeclaration ReplaceBodyWithExpressionClause(TDeclaration declaration, ArrowExpressionClauseSyntax arrow);
protected abstract TDeclaration WithExpressionBody(TDeclaration declaration, ArrowExpressionClauseSyntax expressionBody);
protected override ConversionOperatorDeclarationSyntax WithExpressionBody(ConversionOperatorDeclarationSyntax declaration, ArrowExpressionClauseSyntax expressionBody) => declaration.WithExpressionBody(expressionBody);
public override void VisitArrowExpressionClause(ArrowExpressionClauseSyntax node)
{
}
private static void AnalyzeMethodDeclaration(SyntaxNodeAnalysisContext context, INamedTypeSymbol taskOfTSymbol)
{
var methodDeclaration = (MethodDeclarationSyntax)context.Node;
if (methodDeclaration.Modifiers.Contains(SyntaxKind.AsyncKeyword))
{
return;
}
if ((methodDeclaration.ReturnType as GenericNameSyntax)?.TypeArgumentList?.Arguments.Count != 1)
{
return;
}
ArrowExpressionClauseSyntax expressionBody = methodDeclaration.ExpressionBody;
if (expressionBody != null)
{
ExpressionSyntax expression = expressionBody.Expression?.WalkDownParentheses();
if (expression?.IsKind(
SyntaxKind.NullLiteralExpression,
SyntaxKind.DefaultExpression,
SyntaxKind.DefaultLiteralExpression,
SyntaxKind.ConditionalAccessExpression) != true)
{
return;
}
if (!IsReturnTypeConstructedFromTaskOfT())
{
return;
}
ReportDiagnostic(context, expression);
}
else
{
BlockSyntax body = methodDeclaration.Body;
if (body == null)
{
return;
}
if (!IsReturnTypeConstructedFromTaskOfT())
{
return;
}
AnalyzeBlock(context, body);
}
bool IsReturnTypeConstructedFromTaskOfT()
{
return(context.SemanticModel
.GetDeclaredSymbol(methodDeclaration, context.CancellationToken)?
.ReturnType
.OriginalDefinition
.Equals(taskOfTSymbol) == true);
}
}
private static ExpressionSyntax GetExpressionToCheck(BlockSyntax blockSyntax, ArrowExpressionClauseSyntax expressionBodySyntax,
bool hasReturnValue)
{
return(hasReturnValue
? GetExpressionFromBodyOptions(blockSyntax, expressionBodySyntax)
: (GetSingleStatement(blockSyntax) as ExpressionStatementSyntax)?.Expression);
}
protected override IndexerDeclarationSyntax WithExpressionBody(IndexerDeclarationSyntax declaration, ArrowExpressionClauseSyntax expressionBody) => declaration.WithExpressionBody(expressionBody);
internal override bool TryGetSpeculativeSemanticModelCore(SyntaxTreeSemanticModel parentModel, int position, ArrowExpressionClauseSyntax expressionBody, out SemanticModel speculativeModel)
{
speculativeModel = null;
return(false);
}
private static void HandleArrowExpressionClause(SyntaxNodeAnalysisContext context)
{
ArrowExpressionClauseSyntax arrowExpressionClause = (ArrowExpressionClauseSyntax)context.Node;
CheckToken(context, arrowExpressionClause.ArrowToken, true, true, true);
}
private void VisitAccessorListOrExpressionBody(AccessorListSyntax accessorList, ArrowExpressionClauseSyntax expressionBody)
{
Visit(accessorList);
Visit(expressionBody);
}
public override void VisitArrowExpressionClause(ArrowExpressionClauseSyntax node)
{
throw new NotSupportedException();
}
private void VisitBodyOrExpressionBody(BlockSyntax body, ArrowExpressionClauseSyntax expressionBody)
{
Visit(body);
Visit(expressionBody);
}
public override void VisitArrowExpressionClause(ArrowExpressionClauseSyntax node)
{
this.AddReturnValue(node.Expression);
}
private static ExpressionSyntax GetExpressionFromBodyOptions(BlockSyntax blockSyntax, ArrowExpressionClauseSyntax expressionBodySyntax)
{
return(blockSyntax == null
? expressionBodySyntax?.Expression
: (GetSingleStatement(blockSyntax) as ReturnStatementSyntax)?.Expression);
}
protected override PropertyDeclarationSyntax WithExpressionBody(PropertyDeclarationSyntax declaration, ArrowExpressionClauseSyntax expressionBody) => declaration.WithExpressionBody(expressionBody);
internal override bool TryGetSpeculativeSemanticModelCore(SyntaxTreeSemanticModel parentModel, int position, ArrowExpressionClauseSyntax expressionBody, out SemanticModel speculativeModel)
{
throw ExceptionUtilities.Unreachable;
}
public override void VisitArrowExpressionClause(ArrowExpressionClauseSyntax node)
{
VisitNodeToBind(node.Expression);
}
private static LiteralExpressionSyntax GetNullLiteralOrDefault(ArrowExpressionClauseSyntax expressionBody)
{
return(expressionBody.Expression.IsKind(SyntaxKind.NullLiteralExpression)
? (LiteralExpressionSyntax)expressionBody.Expression
: null);
}
