I don't know how to get information about what actually went wrong from the bot output. @annevk Do you know the right person to ask?

Firefox stability check timed out, feel free to ignore it. An admin can admin-merge it once its approved :).

@stephenmcgruer Would you care to review it while you're here? 😄

I don't understand why .then() isn't catching these exceptions. Isn't that the whole point of promises?

I don't understand why .then() isn't catching these exceptions. Isn't that the whole point of promises?

.then() does catch the exceptions. They get converted to rejected promises, however the rejected promises aren't handled anywhere. They don't cause the test to finish, they are just lost.

I see. This is a rather weird setup.

@jgraham can you review this?

I agree, it's weird.

I think this could be much nicer if we changed these tests to use promise_test instead of async_test (in a follow-up PR). Then do_interface_attribute_asserts could simply return a promise, and we wouldn't need to repeat this thing everywhere:

// do_interface_attribute_asserts must be the last thing we do,
// since it will call done() on a_test.
this.do_interface_attribute_asserts(self, member, a_test);

That said, I'm not very familiar with the code, so maybe I've missed something. 😅