public async Task Execute() { await Publisher.PublishAsync(nameof(CancellationTokenSubscriberTest), "Test Message"); await HandledMessages.WaitOneMessage(CancellationToken); // Explicitly stop Bootstrapper to prove the cancellation token works. var bootstrapper = Container.GetRequiredService <Bootstrapper>(); await bootstrapper.StopAsync(CancellationToken.None); var(message, token) = HandledMessages .OfType <(string Message, CancellationToken Token)>() .Single(); Assert.Equal("Test Message", message); Assert.True(token.IsCancellationRequested); }