static void Analyze([NotNull] IMethodDeclaration methodDeclaration, [NotNull] IHighlightingConsumer consumer)
{
if (!methodDeclaration.IsAsync || !methodDeclaration.IsVoidMethodDeclaration())
{
return; // not an "async void" method
}
var method = methodDeclaration.DeclaredElement;
if (method == null)
{
return; // cannot analyze
}
if (method.GetImmediateSuperMembers().Any())
{
consumer.AddHighlighting(
new AvoidAsyncVoidHighlighting("'void' method overridden or implemented as 'async void'.", methodDeclaration));
return;
}
// find usages
var psiServices = method.GetPsiServices();
Debug.Assert(SearchDomainFactory.Instance != null);
var solutionSearchDomain = SearchDomainFactory.Instance.CreateSearchDomain(psiServices.Solution, false);
var references = psiServices.Finder.FindReferences(method, solutionSearchDomain, NullProgressIndicator.Create());
if (IsPublicSurfaceArea(method))
{
if (references.Length > 0)
{
consumer.AddHighlighting(
new AvoidAsyncVoidHighlighting("'async void' public surface area method with detected usages.", methodDeclaration));
}
else
{
var implicitUseAnnotationProvider = psiServices.GetCodeAnnotationsCache().GetProvider <ImplicitUseAnnotationProvider>();
var useKindFlags = implicitUseAnnotationProvider.IsImplicitlyUsed(method);
if (useKindFlags == null)
{
// [UsedImplicitly] annotation not applied
consumer.AddHighlighting(
new AvoidAsyncVoidHighlighting("'async void' public surface area method without detected usages.", methodDeclaration));
}
}
}
else
{
var count = references.Count(reference => !reference.AssertNotNull().IsEventTarget());
if (count > 0)
{
consumer.AddHighlighting(
new AvoidAsyncVoidHighlighting(
string.Format(
"'async void' method used {0} time{1} not as a direct event handler.",
count.ToString(),
count == 1 ? "" : "s"),
methodDeclaration));
}
}
}