Test Helpers

[penguoir]

When I write tests that check if a notification is being sent, I can easily check whether the code enqueues a Noticed::EventJob. But it's not easy to check which notification the code enqueues.

This recently became a problem because I had one method that enqueued the wrong notification and my tests didn't catch it.

# In the code:
def notify_user
  WrongNotifier.deliver
end

# In the test:
assert_enqueued_jobs only: Noticed::EventJob
# Passes!

I think it would be a good idea to add a simpler helper similar to ActiveJob::TestHelper which allows for testing the notification being sent.

Happy to spend some time here if needed!

[penguoir]

Am I missing anything obvious here? Or am I ok to start working on a PR?