internal static void WaitForBackgroundToComplete <TData, TTag>(this AsyncTagger <TData, TTag> asyncTagger, TestableSynchronizationContext synchronizationContext)
where TTag : ITag
{
while (asyncTagger.AsyncBackgroundRequestData.HasValue)
{
synchronizationContext.RunAll();
Thread.Yield();
}
}
public void GetTags()
{
Create("dog", "cat", "fish", "dog");
_asyncTaggerSource.SetBackgroundFunc(span => TestUtils.GetDogTags(span));
_asyncTagger.GetTags(_textBuffer.GetLineRange(0).Extent);
Assert.True(_asyncTagger.AsyncBackgroundRequestData.HasValue);
// Background is done. Because we control the synchronization context though the foreground
// thread still sees it as active and hence will continue to queue data on it
_asyncTagger.AsyncBackgroundRequestData.Value.Task.Wait();
Assert.True(_asyncTagger.AsyncBackgroundRequestData.HasValue);
_asyncTagger.GetTags(_textBuffer.GetLineRange(3).Extent);
// Clear the queue, the missing work will be seen and immedieatly requeued
TestableSynchronizationContext.RunAll();
Assert.True(_asyncTagger.AsyncBackgroundRequestData.HasValue);
WaitForBackgroundToComplete();
var tags = _asyncTagger.GetTags(_textBuffer.GetExtent());
Assert.Equal(
new[] { _textBuffer.GetLineSpan(0, 3), _textBuffer.GetLineSpan(3, 3) },
tags.Select(x => x.Span));
}