public static bool IsDefaultSwitchLabel(SwitchLabelSyntax node)
{
// default:
if (node.IsKind(SyntaxKind.DefaultSwitchLabel))
{
return(true);
}
if (node.IsKind(SyntaxKind.CasePatternSwitchLabel, out CasePatternSwitchLabelSyntax? @case))
{
// case _:
if (@case.Pattern.IsKind(SyntaxKind.DiscardPattern))
{
return(@case.WhenClause == null);
}
// case var _:
// case var x:
if (@case.Pattern.IsKind(SyntaxKind.VarPattern, out VarPatternSyntax? varPattern) &&
varPattern.Designation.IsKind(SyntaxKind.DiscardDesignation, SyntaxKind.SingleVariableDesignation))
{
return(@case.WhenClause == null);
}
}
return(false);
}
public static void Analyze(SyntaxNodeAnalysisContext context, SwitchSectionSyntax switchSection)
{
SyntaxList <SwitchLabelSyntax> labels = switchSection.Labels;
for (int i = 0; i < labels.Count - 1; i++)
{
SwitchLabelSyntax label = labels[i];
if (label.IsKind(SyntaxKind.DefaultSwitchLabel))
{
TextSpan span = TextSpan.FromBounds(label.Span.End, labels.Last().Span.Start);
if (!switchSection.ContainsDirectives(span))
{
context.ReportDiagnostic(
DiagnosticDescriptors.DefaultLabelShouldBeLastLabelInSwitchSection,
label);
}
}
}
}