public static async Task ComputeRefactoringsAsync(RefactoringContext context, CastExpressionSyntax castExpression)
{
if (context.IsRefactoringEnabled(RefactoringIdentifiers.ReplaceCastWithAs) &&
context.Span.IsEmptyAndContainedInSpanOrBetweenSpans(castExpression))
{
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(castExpression.Type, context.CancellationToken);
if (typeSymbol?.IsErrorType() == false &&
typeSymbol.IsReferenceTypeOrNullableType())
{
Document document = context.Document;
context.RegisterRefactoring(
"Replace cast with 'as'",
cancellationToken =>
{
BinaryExpressionSyntax newNode = CSharpFactory.AsExpression(castExpression.Expression.WithTriviaFrom(castExpression.Type), castExpression.Type.WithTriviaFrom(castExpression.Expression))
.WithTriviaFrom(castExpression)
.WithFormatterAnnotation();
return(document.ReplaceNodeAsync(castExpression, newNode, cancellationToken));
},
RefactoringIdentifiers.ReplaceCastWithAs);
}
}
}
private static Task <Document> RefactorAsync(
Document document,
CastExpressionSyntax castExpression,
CancellationToken cancellationToken)
{
ExpressionSyntax expression = castExpression.Expression;
TypeSyntax type = castExpression.Type;
BinaryExpressionSyntax newNode = CSharpFactory.AsExpression(expression.WithTriviaFrom(type), type.WithTriviaFrom(expression))
.WithTriviaFrom(castExpression)
.WithFormatterAnnotation();
return(document.ReplaceNodeAsync(castExpression, newNode, cancellationToken));
}