private void MoveConstraint(
CodeFixContext context,
Diagnostic diagnostic,
TypeParameterConstraintInfo constraintInfo,
int index)
{
CodeAction codeAction = CodeAction.Create(
$"Move constraint '{constraintInfo.Constraint}'",
ct =>
{
SeparatedSyntaxList <TypeParameterConstraintSyntax> newConstraints = constraintInfo.Constraints
.Remove(constraintInfo.Constraint)
.Insert(index, constraintInfo.Constraint);
TypeParameterConstraintClauseSyntax newNode = constraintInfo.ConstraintClause
.WithConstraints(newConstraints)
.WithFormatterAnnotation();
return(context.Document.ReplaceNodeAsync(constraintInfo.ConstraintClause, newNode, ct));
},
GetEquivalenceKey(diagnostic));
context.RegisterCodeFix(codeAction, diagnostic);
}
public override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.GetSyntaxRootAsync().ConfigureAwait(false);
if (!TryFindFirstAncestorOrSelf(root, context.Span, out TypeParameterConstraintSyntax constraint))
{
return;
}
foreach (Diagnostic diagnostic in context.Diagnostics)
{
switch (diagnostic.Id)
{
case CompilerDiagnosticIdentifiers.CS0401_NewConstraintMustBeLastConstraintSpecified:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.MoveConstraint, context.Document, root.SyntaxTree))
{
break;
}
TypeParameterConstraintInfo constraintInfo = SyntaxInfo.TypeParameterConstraintInfo(constraint);
if (!constraintInfo.Success)
{
break;
}
MoveConstraint(context, diagnostic, constraintInfo, constraintInfo.Constraints.Count - 1);
break;
}
case CompilerDiagnosticIdentifiers.CS0405_DuplicateConstraintForTypeParameter:
{
if (IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveConstraint, context.Document, root.SyntaxTree))
{
RemoveConstraint(context, diagnostic, constraint);
}
break;
}
case CompilerDiagnosticIdentifiers.CS0449_ClassOrStructConstraintMustComeBeforeAnyOtherConstraints:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.MoveConstraint, context.Document, root.SyntaxTree))
{
break;
}
TypeParameterConstraintInfo constraintInfo = SyntaxInfo.TypeParameterConstraintInfo(constraint);
if (!constraintInfo.Success)
{
break;
}
if (constraintInfo.IsDuplicateConstraint)
{
RemoveConstraint(context, diagnostic, constraint);
}
else
{
MoveConstraint(context, diagnostic, constraintInfo, 0);
}
break;
}
case CompilerDiagnosticIdentifiers.CS0450_CannotSpecifyBothConstraintClassAndClassOrStructConstraint:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveConstraint, context.Document, root.SyntaxTree))
{
break;
}
TypeParameterConstraintInfo constraintInfo = SyntaxInfo.TypeParameterConstraintInfo(constraint);
if (!constraintInfo.Success)
{
break;
}
RemoveConstraint(context, diagnostic, constraint);
TypeParameterConstraintSyntax classConstraint = constraintInfo.Constraints.Find(SyntaxKind.ClassConstraint);
if (classConstraint != null)
{
RemoveConstraint(context, diagnostic, classConstraint);
}
TypeParameterConstraintSyntax structConstraint = constraintInfo.Constraints.Find(SyntaxKind.StructConstraint);
if (structConstraint != null)
{
RemoveConstraint(context, diagnostic, structConstraint);
}
break;
}
case CompilerDiagnosticIdentifiers.CS0451_NewConstraintCannotBeUsedWithStructConstraint:
{
if (!IsEnabled(diagnostic.Id, CodeFixIdentifiers.RemoveConstraint, context.Document, root.SyntaxTree))
{
break;
}
RemoveConstraint(context, diagnostic, constraint);
TypeParameterConstraintInfo constraintInfo = SyntaxInfo.TypeParameterConstraintInfo(constraint);
if (!constraintInfo.Success)
{
break;
}
TypeParameterConstraintSyntax structConstraint = constraintInfo.Constraints.Find(SyntaxKind.StructConstraint);
RemoveConstraint(context, diagnostic, structConstraint);
break;
}
}
}
}
