private IEnumerable <IGrouping <SyntaxNode, Diagnostic> > GetDiagnosticsGroupedByMember(
ImmutableArray <Diagnostic> diagnostics,
ISyntaxFactsService syntaxFacts,
SyntaxNode root,
out string diagnosticId,
out UnusedValuePreference preference,
out bool removeAssignments)
{
diagnosticId = diagnostics[0].Id;
var success = AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.TryGetUnusedValuePreference(diagnostics[0], out preference);
Debug.Assert(success);
removeAssignments = AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.GetIsRemovableAssignmentDiagnostic(diagnostics[0]);
#if DEBUG
foreach (var diagnostic in diagnostics)
{
Debug.Assert(diagnosticId == diagnostic.Id);
Debug.Assert(AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.TryGetUnusedValuePreference(diagnostic, out var diagnosticPreference) &&
diagnosticPreference == preference);
Debug.Assert(removeAssignments == AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.GetIsRemovableAssignmentDiagnostic(diagnostic));
}
#endif
return(GetDiagnosticsGroupedByMember(diagnostics, syntaxFacts, root));
}
private static string GetEquivalenceKey(Diagnostic diagnostic)
{
if (!AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.TryGetUnusedValuePreference(diagnostic, out var preference))
{
return(string.Empty);
}
var isRemovableAssignment = AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.GetIsRemovableAssignmentDiagnostic(diagnostic);
return(GetEquivalenceKey(preference, isRemovableAssignment));
}
public sealed override Task RegisterCodeFixesAsync(CodeFixContext context)
{
var diagnostic = context.Diagnostics[0];
if (!AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.TryGetUnusedValuePreference(diagnostic, out var preference))
{
return(Task.CompletedTask);
}
var isRemovableAssignment = AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.GetIsRemovableAssignmentDiagnostic(diagnostic);
string title;
if (isRemovableAssignment)
{
// Recommend removing the redundant constant value assignment.
title = FeaturesResources.Remove_redundant_assignment;
}
else
{
// Recommend using discard/unused local for redundant non-constant assignment.
switch (preference)
{
case UnusedValuePreference.DiscardVariable:
if (IsForEachIterationVariableDiagnostic(diagnostic, context.Document, context.CancellationToken))
{
// Do not offer a fix to replace unused foreach iteration variable with discard.
// User should probably replace it with a for loop based on the collection length.
return(Task.CompletedTask);
}
title = FeaturesResources.Use_discard_underscore;
break;
case UnusedValuePreference.UnusedLocalVariable:
title = FeaturesResources.Use_discarded_local;
break;
default:
return(Task.CompletedTask);
}
}
context.RegisterCodeFix(
new MyCodeAction(
title,
c => FixAsync(context.Document, diagnostic, c),
equivalenceKey: GetEquivalenceKey(preference, isRemovableAssignment)),
diagnostic);
return(Task.CompletedTask);
}
public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
var diagnostic = context.Diagnostics[0];
if (!AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.TryGetUnusedValuePreference(diagnostic, out var preference))
{
return;
}
var isRemovableAssignment = AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.GetIsRemovableAssignmentDiagnostic(diagnostic);
string title;
if (isRemovableAssignment)
{
// Recommend removing the redundant constant value assignment.
title = FeaturesResources.Remove_redundant_assignment;
}
else
{
// Recommend using discard/unused local for redundant non-constant assignment.
switch (preference)
{
case UnusedValuePreference.DiscardVariable:
if (IsForEachIterationVariableDiagnostic(diagnostic, context.Document, context.CancellationToken))
{
// Do not offer a fix to replace unused foreach iteration variable with discard.
// User should probably replace it with a for loop based on the collection length.
return;
}
title = FeaturesResources.Use_discard_underscore;
// Check if this is compound assignment which is not parented by an expression statement,
// for example "return x += M();" OR "=> x ??= new C();"
// If so, we will be replacing this compound assignment with the underlying binary operation.
// For the above examples, it will be "return x + M();" AND "=> x ?? new C();" respectively.
// For these cases, we want to show the title as "Remove redundant assignment" instead of "Use discard _".
var syntaxFacts = context.Document.GetLanguageService <ISyntaxFactsService>();
var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
var node = root.FindNode(context.Span, getInnermostNodeForTie: true);
if (syntaxFacts.IsLeftSideOfCompoundAssignment(node) &&
!syntaxFacts.IsExpressionStatement(node.Parent))
{
title = FeaturesResources.Remove_redundant_assignment;
}
break;
case UnusedValuePreference.UnusedLocalVariable:
title = FeaturesResources.Use_discarded_local;
break;
default:
return;
}
}
context.RegisterCodeFix(
new MyCodeAction(
title,
c => FixAsync(context.Document, diagnostic, c),
equivalenceKey: GetEquivalenceKey(preference, isRemovableAssignment)),
diagnostic);
return;
}
