Simple class for tests involving a SynchronizationContext
Recently I had to test a class which heavily depended upon a SynchronizationContext. This threw me off for about half an hour as I didn't want to write multi-threaded unit tests. Multi-threaded code is difficult enough without adding needless threads.
The solution I came up with is simple and gives the unit test a large degree of control over the execution of posted delegates. The resulting tests were much easier to code and understand.
public sealed class TestSynchronizationContext : SynchronizationContext {
private List<Tuple<SendOrPostCallback, object>> m_pending
= new List<Tuple<SendOrPostCallback, object>>();
public override void Send(SendOrPostCallback d, object state) {
d(state);
}
public override void Post(SendOrPostCallback d, object state) {
m_pending.Add(Tuple.Create(d, state));
}
public void RunAllPosted() {
m_pending.ForEach(x => x.First(x.Second));
}
}
