976810 - Async errors in Promise.then() in unit test getting lost

Status: RESOLVED INVALID

(Add-on SDK Graveyard :: General, defect)

Description

[willmarquardt]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:27.0) Gecko/20100101 Firefox/27.0 (Beta/Release)
Build ID: 20140212131424

Steps to reproduce:

Created a test module with the following code

exports["test rest get article"] = function(assert, done) {
  rest.get('article', articleUrl).then(function(article) {
    fakeVar.length;
    console.log('Should see console.error above');
    done();
  }
}


Actual results:

Test failed after it timed out with nothing printed to the console.


Expected results:

Test should have failed immediately (after rest.get() ) with both the error and the log printed to the console.

Comment 1

[Dave Townsend [:mossop]]

The code you've entered is invalid, it's missing a closing bracket. Even if it weren't when an exception is thrown in a promise handler it becomes a rejected promise which you aren't handling. As this is all async code it's difficult to impossible for the test harness to handle this automatically except by timing out.

You need to do something like this:

exports["test rest get article"] = function(assert, done) {
  rest.get('article', articleUrl).then(function(article) {
    fakeVar.length;
    console.log('Should see console.error above');
  }).then(done, function(error) {
    assert.fail(error);
    done();
  });
}

Comment 2

[willmarquardt]

Awesome, thanks for the helpful code. Sorry for posting as a bug.

Comment 3

[Matteo Ferretti [:zer0] [:matteo]]

Never be sorry to post a bug, it's better have people willing to help us to fix issues that discover all of them by ourselves. :)

Comment 4

[David Teller [:Yoric] - still alive but not very active]

Side-note: bug 998277 might actually help here.