public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken)
.ConfigureAwait(false);
Diagnostic diagnostic = context.Diagnostics.First();
TextSpan diagnosticSpan = diagnostic.Location.SourceSpan;
var argumentListNode = root.FindNode(diagnosticSpan)
.Ancestors()
.OfType <ArgumentListSyntax>()
.FirstOrDefault();
var firstParameterIdentifier = argumentListNode.Arguments
.First()
.Expression as IdentifierNameSyntax;
string firstParameterName = firstParameterIdentifier.Identifier.ValueText;
string fixTitle = $"Change second argument to {firstParameterName}";
context.RegisterCodeFix(
diagnostic: diagnostic,
action: CodeAction.Create(
title: fixTitle,
equivalenceKey: fixTitle,
createChangedDocument: cancellationToken =>
AnalyzerHelpers.ChangeArgumentAsync(
context.Document,
argumentListNode,
firstParameterName,
cancellationToken)));
}
public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken)
.ConfigureAwait(false);
Diagnostic diagnostic = context.Diagnostics.First();
TextSpan diagnosticSpan = diagnostic.Location.SourceSpan;
// Find the method that contains the EnsureArg call.
var containingMethod = root.FindNode(diagnosticSpan)
.Ancestors()
.OfType <MemberDeclarationSyntax>()
.FirstOrDefault();
if (containingMethod == null)
{
return;
}
var argumentListNode = root.FindNode(diagnosticSpan)
.Ancestors()
.OfType <ArgumentListSyntax>()
.FirstOrDefault();
var methodParameters = AnalyzerHelpers.GetParameters(containingMethod);
foreach (string parameterName in methodParameters)
{
string fixTitle = $"Change first argument to {parameterName}";
context.RegisterCodeFix(
diagnostic: diagnostic,
action: CodeAction.Create(
title: fixTitle,
equivalenceKey: fixTitle,
createChangedDocument: cancellationToken =>
AnalyzerHelpers.ChangeArgumentAsync(
context.Document,
argumentListNode,
parameterName,
cancellationToken)));
}
}
private void AnalyzeNode(SyntaxNodeAnalysisContext context)
{
if (!context.Node.IsKind(SyntaxKind.InvocationExpression))
{
return;
}
var invocationExpr = context.Node as InvocationExpressionSyntax;
if (!IsNodeEnsureArgCall(context, invocationExpr))
{
return;
}
var argumentList = invocationExpr.ArgumentList as ArgumentListSyntax;
if ((argumentList?.Arguments.Count ?? 0) < 1)
{
return;
}
var firstArgumentNameSyntax = argumentList.Arguments[0].Expression as IdentifierNameSyntax;
if (firstArgumentNameSyntax == null)
{
return;
}
var methodDeclaration = context.Node
.Ancestors()
.OfType <MemberDeclarationSyntax>()
.FirstOrDefault();
string firstArgumentName = firstArgumentNameSyntax.Identifier.ValueText;
if (methodDeclaration != null)
{
var methodParameters = AnalyzerHelpers.GetParameters(methodDeclaration);
if (!methodParameters.Contains(firstArgumentName))
{
var diagnostic =
Diagnostic.Create(
Rule1,
firstArgumentNameSyntax.GetLocation(),
firstArgumentName,
GetMethodName(methodDeclaration));
context.ReportDiagnostic(diagnostic);
}
}
if (argumentList.Arguments.Count >= 2)
{
ExpressionSyntax secondArgument = argumentList.Arguments[1].Expression;
string secondParameterText = null;
Location diagnosticLocation = null;
// String Literal e.g. Ensure.Arg(a, "b");
if (secondArgument.IsKind(SyntaxKind.StringLiteralExpression))
{
var stringLiteral = secondArgument as LiteralExpressionSyntax;
secondParameterText = stringLiteral.Token.ValueText;
diagnosticLocation = stringLiteral.GetLocation();
if (secondParameterText == firstArgumentName)
{
var diagnostic =
Diagnostic.Create(
Rule3,
diagnosticLocation,
secondParameterText);
context.ReportDiagnostic(diagnostic);
}
}
// Detect if using nameof operator e.g. Ensure.Arg(a, nameof(b));
if (secondArgument.IsKind(SyntaxKind.InvocationExpression))
{
var invocationExpression = secondArgument as InvocationExpressionSyntax;
var nameOfIdentifier = invocationExpression.ChildNodes().FirstOrDefault() as IdentifierNameSyntax;
if (nameOfIdentifier.Identifier.ValueText == "nameof")
{
// Definitely nameof operater, keep digging to get to the identifier argument.
var nameOfIdentifierArgument = invocationExpression.DescendantNodes()
.OfType <ArgumentListSyntax>()
.FirstOrDefault()
?.Arguments
.FirstOrDefault()
?.Expression as IdentifierNameSyntax;
secondParameterText = nameOfIdentifierArgument?.Identifier.ValueText;
diagnosticLocation = invocationExpression.GetLocation();
}
}
if (secondParameterText != firstArgumentName)
{
var diagnostic =
Diagnostic.Create(
Rule2,
diagnosticLocation,
secondParameterText,
firstArgumentName);
context.ReportDiagnostic(diagnostic);
}
}
var methodIdentifier = invocationExpr.Parent
.ChildNodes()
.OfType <IdentifierNameSyntax>()
.FirstOrDefault();
if (methodIdentifier == null)
{
var diagnostic = Diagnostic.Create(
Rule4,
invocationExpr.GetLocation());
context.ReportDiagnostic(diagnostic);
}
}