public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
SyntaxNode node = root.FindNode(context.Span);
SyntaxNode binaryExpressionSyntax = GetBinaryExpression(node);
if (!IsEqualsOperator(binaryExpressionSyntax) && !IsNotEqualsOperator(binaryExpressionSyntax))
{
return;
}
SemanticModel model = await context.Document.GetSemanticModelAsync(context.CancellationToken).ConfigureAwait(false);
INamedTypeSymbol systemSingleType = model.Compilation.GetTypeByMetadataName("System.Single");
INamedTypeSymbol systemDoubleType = model.Compilation.GetTypeByMetadataName("System.Double");
if (systemSingleType == null || systemDoubleType == null)
{
return;
}
FixResolution resolution = TryGetFixResolution(binaryExpressionSyntax, model, systemSingleType, systemDoubleType);
if (resolution != null)
{
var action = CodeAction.Create(MicrosoftNetCoreAnalyzersResources.TestForNaNCorrectlyMessage,
async ct => await ConvertToMethodInvocation(context, resolution).ConfigureAwait(false),
equivalenceKey: MicrosoftNetCoreAnalyzersResources.TestForNaNCorrectlyMessage);
context.RegisterCodeFix(action, context.Diagnostics);
}
}
public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
SyntaxNode node = root.FindNode(context.Span);
SyntaxNode binaryExpressionSyntax = GetBinaryExpression(node);
if (!IsEqualsOperator(binaryExpressionSyntax) && !IsNotEqualsOperator(binaryExpressionSyntax))
{
return;
}
SemanticModel model = await context.Document.GetSemanticModelAsync(context.CancellationToken).ConfigureAwait(false);
FixResolution resolution = TryGetFixResolution(binaryExpressionSyntax, model);
if (resolution != null)
{
var methodInvocationAction = CodeAction.Create(MicrosoftNetCoreAnalyzersResources.TestForEmptyStringsUsingStringLengthMessage,
async ct => await ConvertToMethodInvocation(context, resolution).ConfigureAwait(false),
equivalenceKey: "TestForEmptyStringCorrectlyUsingIsNullOrEmpty");
context.RegisterCodeFix(methodInvocationAction, context.Diagnostics);
var stringLengthAction = CodeAction.Create(MicrosoftNetCoreAnalyzersResources.TestForEmptyStringsUsingStringLengthMessage,
async ct => await ConvertToStringLengthComparison(context, resolution).ConfigureAwait(false),
equivalenceKey: "TestForEmptyStringCorrectlyUsingStringLength");
context.RegisterCodeFix(stringLengthAction, context.Diagnostics);
}
}
private static async Task <Document> ConvertToMethodInvocation(CodeFixContext context, FixResolution fixResolution)
{
DocumentEditor editor = await DocumentEditor.CreateAsync(context.Document, context.CancellationToken).ConfigureAwait(false);
SyntaxNode typeNameSyntax = editor.Generator.TypeExpression(SpecialType.System_String);
SyntaxNode nullOrEmptyMemberSyntax = editor.Generator.MemberAccessExpression(typeNameSyntax, "IsNullOrEmpty");
SyntaxNode nullOrEmptyInvocationSyntax = editor.Generator.InvocationExpression(nullOrEmptyMemberSyntax, fixResolution.ComparisonOperand.WithoutTrailingTrivia());
SyntaxNode replacementSyntax = fixResolution.UsesEqualsOperator ? nullOrEmptyInvocationSyntax : editor.Generator.LogicalNotExpression(nullOrEmptyInvocationSyntax);
SyntaxNode replacementAnnotatedSyntax = replacementSyntax.WithAdditionalAnnotations(Formatter.Annotation).WithTriviaFrom(fixResolution.BinaryExpressionSyntax);
editor.ReplaceNode(fixResolution.BinaryExpressionSyntax, replacementAnnotatedSyntax);
return(editor.GetChangedDocument());
}
private async Task <Document> ConvertToStringLengthComparison(CodeFixContext context, FixResolution fixResolution)
{
DocumentEditor editor = await DocumentEditor.CreateAsync(context.Document, context.CancellationToken).ConfigureAwait(false);
SyntaxNode leftOperand = GetLeftOperand(fixResolution.BinaryExpressionSyntax);
SyntaxNode rightOperand = GetRightOperand(fixResolution.BinaryExpressionSyntax);
// Take the below example:
// if (f == String.Empty) ...
// The comparison operand, f, will now become 'f.Length' and a the other operand will become '0'
SyntaxNode zeroLengthSyntax = editor.Generator.LiteralExpression(0);
if (leftOperand == fixResolution.ComparisonOperand)
{
leftOperand = editor.Generator.MemberAccessExpression(leftOperand, "Length");
rightOperand = zeroLengthSyntax.WithTriviaFrom(rightOperand);
}
else
{
leftOperand = zeroLengthSyntax;
rightOperand = editor.Generator.MemberAccessExpression(rightOperand.WithoutTrivia(), "Length");
}
SyntaxNode replacementSyntax = fixResolution.UsesEqualsOperator ?
editor.Generator.ValueEqualsExpression(leftOperand, rightOperand) :
editor.Generator.ValueNotEqualsExpression(leftOperand, rightOperand);
SyntaxNode replacementAnnotatedSyntax = replacementSyntax.WithAdditionalAnnotations(Formatter.Annotation);
editor.ReplaceNode(fixResolution.BinaryExpressionSyntax, replacementAnnotatedSyntax);
return(editor.GetChangedDocument());
}
private async Task <Document> ConvertToMethodInvocation(CodeFixContext context, FixResolution fixResolution)
{
DocumentEditor editor = await DocumentEditor.CreateAsync(context.Document, context.CancellationToken).ConfigureAwait(false);
SyntaxNode typeNameSyntax = editor.Generator.TypeExpression(fixResolution.FloatingSystemType);
SyntaxNode nanMemberSyntax = editor.Generator.MemberAccessExpression(typeNameSyntax, "IsNaN");
SyntaxNode nanMemberInvocationSyntax = editor.Generator.InvocationExpression(nanMemberSyntax, fixResolution.ComparisonOperand);
SyntaxNode replacementSyntax = fixResolution.UsesEqualsOperator ? nanMemberInvocationSyntax : editor.Generator.LogicalNotExpression(nanMemberInvocationSyntax);
SyntaxNode replacementAnnotatedSyntax = replacementSyntax.WithAdditionalAnnotations(Formatter.Annotation);
editor.ReplaceNode(fixResolution.BinaryExpressionSyntax, replacementAnnotatedSyntax);
return(editor.GetChangedDocument());
}
private async Task<Document> ConvertToMethodInvocation(CodeFixContext context, FixResolution fixResolution)
{
DocumentEditor editor = await DocumentEditor.CreateAsync(context.Document, context.CancellationToken).ConfigureAwait(false);
SyntaxNode typeNameSyntax = editor.Generator.TypeExpression(fixResolution.FloatingSystemType);
SyntaxNode nanMemberSyntax = editor.Generator.MemberAccessExpression(typeNameSyntax, "IsNaN");
SyntaxNode nanMemberInvocationSyntax = editor.Generator.InvocationExpression(nanMemberSyntax, fixResolution.ComparisonOperand);
SyntaxNode replacementSyntax = fixResolution.UsesEqualsOperator ? nanMemberInvocationSyntax : editor.Generator.LogicalNotExpression(nanMemberInvocationSyntax);
SyntaxNode replacementAnnotatedSyntax = replacementSyntax.WithAdditionalAnnotations(Formatter.Annotation);
editor.ReplaceNode(fixResolution.BinaryExpressionSyntax, replacementAnnotatedSyntax);
return editor.GetChangedDocument();
}
