public static ISet<INamespaceSymbol> GetUsingNamespacesInScope(this SemanticModel semanticModel, SyntaxNode location)
{
// Avoiding linq here for perf reasons. This is used heavily in the AddImport service
HashSet<INamespaceSymbol> result = null;
foreach (var @using in location.GetEnclosingUsingDirectives())
{
if (@using.Alias == null)
{
var symbolInfo = semanticModel.GetSymbolInfo(@using.Name);
if (symbolInfo.Symbol != null && symbolInfo.Symbol.Kind == SymbolKind.Namespace)
{
result = result ?? new HashSet<INamespaceSymbol>();
result.Add((INamespaceSymbol)symbolInfo.Symbol);
}
}
}
return (ISet<INamespaceSymbol>)result ?? ImmutableHashSet<INamespaceSymbol>.Empty;
}
private static IList<UsingDirectiveSyntax> GetUsingDirectivesToAdd(
SyntaxNode contextLocation, XElement snippetNode, XElement importsNode, CancellationToken cancellationToken)
{
var namespaceXmlName = XName.Get("Namespace", snippetNode.Name.NamespaceName);
var existingUsings = contextLocation.GetEnclosingUsingDirectives();
var newUsings = new List<UsingDirectiveSyntax>();
foreach (var import in importsNode.Elements(XName.Get("Import", snippetNode.Name.NamespaceName)))
{
var namespaceElement = import.Element(namespaceXmlName);
if (namespaceElement == null)
{
continue;
}
var namespaceToImport = namespaceElement.Value.Trim();
if (string.IsNullOrEmpty(namespaceToImport))
{
continue;
}
var candidateUsing = SyntaxFactory.ParseCompilationUnit("using " + namespaceToImport + ";").DescendantNodes().OfType<UsingDirectiveSyntax>().FirstOrDefault();
if (candidateUsing == null)
{
continue;
}
if (!existingUsings.Any(u => u.IsEquivalentTo(candidateUsing, topLevel: false)))
{
newUsings.Add(candidateUsing.WithAdditionalAnnotations(Formatter.Annotation).WithAppendedTrailingTrivia(SyntaxFactory.CarriageReturnLineFeed));
}
}
return newUsings;
}
