Don’t let Ember.js swallow errors in your promises

Update: 25/07/2013 : The solution described below does not work with RC6 .. You will need to get ember-latest.

Are you finding that errors occurring in your promise handlers are being swallowed silently by Ember.js ? I had written some code that looked like this:

The problem was that I was calling this.getXXX while in the scope of the then() function, which is globally scoped. This was easily fixed by passing a reference to controller scope, but normally these kind of mistakes are logged to the console.

Turns out the then() callback function was being executed by Ember.js in a try/catch block, with the error being passed to the default reject handler which was swallowing the error.

Luckily @teddyzeenny was in the IRC channel to offer some advice. Heres a code snippet that you can add to your Ember.js application to make sure these errors get logged to the console.