public async override Task RegisterCodeFixesAsync(CodeFixContext context)
{
var document = context.Document;
var cancellationToken = context.CancellationToken;
var span = context.Span;
var diagnostics = context.Diagnostics;
var model = await document.GetSemanticModelAsync(cancellationToken);
var root = await document.GetSyntaxRootAsync(cancellationToken);
var diagnostic = diagnostics.First();
var node = root.FindNode(context.Span) as IfStatementSyntax;
if (node == null)
{
return;
}
int foundCasts;
foreach (var fix in UseAsAndNullCheckCodeRefactoringProvider.ScanIfElse(model, document, root, node, node.Condition.SkipParens() as BinaryExpressionSyntax, out foundCasts))
{
context.RegisterCodeFix(fix, diagnostic);
}
}
internal static bool CheckIfElse(SemanticModel ctx, SyntaxNode root, IfStatementSyntax ifElseStatement, out BinaryExpressionSyntax isExpression)
{
isExpression = null;
var embeddedStatment = ifElseStatement.Statement;
TypeInfo rr;
ExpressionSyntax castToType;
List <SyntaxNode> foundCasts;
var innerCondition = ifElseStatement.Condition.SkipParens();
if (innerCondition != null && innerCondition.IsKind(SyntaxKind.LogicalNotExpression))
{
var c2 = ((PrefixUnaryExpressionSyntax)innerCondition).Operand.SkipParens();
if (c2.IsKind(SyntaxKind.IsExpression))
{
isExpression = c2 as BinaryExpressionSyntax;
castToType = isExpression.Right;
rr = ctx.GetTypeInfo(castToType);
if (rr.Type == null || !rr.Type.IsReferenceType)
{
return(false);
}
SyntaxNode searchStmt = embeddedStatment;
if (UseAsAndNullCheckCodeRefactoringProvider.IsControlFlowChangingStatement(searchStmt))
{
searchStmt = ifElseStatement.Parent;
foundCasts = searchStmt.DescendantNodesAndSelf(n => !UseAsAndNullCheckCodeRefactoringProvider.IsCast(ctx, n, rr.Type)).Where(arg => arg.SpanStart >= ifElseStatement.SpanStart && UseAsAndNullCheckCodeRefactoringProvider.IsCast(ctx, arg, rr.Type)).ToList();
foundCasts.AddRange(ifElseStatement.Condition.DescendantNodesAndSelf(n => !UseAsAndNullCheckCodeRefactoringProvider.IsCast(ctx, n, rr.Type)).Where(arg => arg.SpanStart > c2.Span.End && UseAsAndNullCheckCodeRefactoringProvider.IsCast(ctx, arg, rr.Type)));
}
else
{
foundCasts = new List <SyntaxNode>();
}
return(foundCasts.Count > 0);
}
return(false);
}
isExpression = innerCondition as BinaryExpressionSyntax;
if (isExpression == null)
{
return(false);
}
castToType = isExpression.Right;
rr = ctx.GetTypeInfo(castToType);
if (rr.Type == null || !rr.Type.IsReferenceType)
{
return(false);
}
foundCasts = embeddedStatment.DescendantNodesAndSelf(n => !UseAsAndNullCheckCodeRefactoringProvider.IsCast(ctx, n, rr.Type)).Where(arg => UseAsAndNullCheckCodeRefactoringProvider.IsCast(ctx, arg, rr.Type)).ToList();
foundCasts.AddRange(ifElseStatement.Condition.DescendantNodesAndSelf(n => !UseAsAndNullCheckCodeRefactoringProvider.IsCast(ctx, n, rr.Type)).Where(arg => arg.SpanStart > innerCondition.Span.End && UseAsAndNullCheckCodeRefactoringProvider.IsCast(ctx, arg, rr.Type)));
return(foundCasts.Count > 0);
}