private static void CheckUsingDeclaration(SyntaxNodeAnalysisContext context, UsingDirectiveSyntax usingDirective)
{
if (!usingDirective.Parent.IsKind(SyntaxKind.NamespaceDeclaration))
{
// Usings outside of a namespace are always qualified.
return;
}
if (!usingDirective.StaticKeyword.IsKind(SyntaxKind.None))
{
// using static types is not considered.
return;
}
if (usingDirective.HasNamespaceAliasQualifier())
{
// global qualified namespaces are OK.
return;
}
var symbol = context.SemanticModel.GetSymbolInfo(usingDirective.Name, context.CancellationToken).Symbol;
if (symbol == null)
{
// if there is no symbol, do not proceed.
return;
}
if (symbol is INamedTypeSymbol typeSymbol &&
typeSymbol.IsTupleType())
{
symbol = typeSymbol.TupleUnderlyingType();
}
string symbolString = symbol.ToQualifiedString(usingDirective.Name);
string usingString = UsingDirectiveSyntaxToCanonicalString(usingDirective);
if ((symbolString != usingString) && !usingDirective.StartsWithAlias(context.SemanticModel, context.CancellationToken))
{
switch (symbol.Kind)
{
case SymbolKind.Namespace:
context.ReportDiagnostic(Diagnostic.Create(DescriptorNamespace, usingDirective.GetLocation(), symbolString));
break;
case SymbolKind.NamedType:
var containingNamespace = ((NamespaceDeclarationSyntax)usingDirective.Parent).Name.ToString();
if (containingNamespace != symbol.ContainingNamespace.ToString())
{
context.ReportDiagnostic(Diagnostic.Create(DescriptorType, usingDirective.GetLocation(), symbolString));
}
break;
}
}
}
