public async Task InvokesHandler() { var log = new FilterLog { }; var logsHandled = new List <FilterLog>(); _matcher .Setup(m => m.IsMatch(log)).Returns(true); _handler .Setup(m => m.HandleAsync(_eventSubscription, _eventAbis, log)) .Returns <IEventSubscription, EventABI[], FilterLog[]>((subscription, abi, l) => { logsHandled.AddRange(l); return(Task.CompletedTask); }); await _eventSubscription.ExecuteAsync(log); Assert.Single(logsHandled, log); }