4 ms·

Wouldn't using the second parameter of .then() to catch exceptions work instead of .catch()? http://stackoverflow.com/a/33278420 http://stackoverflow.com/a/332

• pornel 9y ago
  It doesn't matter. The problem is that `callback(null)` throws, and in the `Promise` land this will never result in an uncaught exception. An exception directly inside any `Promise` callback produces another `Promise` in the chain instead. You could at best use `setTimeout` or `nextTick` to escape from `Promise`'s call stack and throw there.
  • mariusc23 9y ago
    Good point! I thought of solving the callback getting called twice problem and didn't think of the bigger picture that mocha needs to catch the assertion error. I like the setTimeout/nextTick trick (well, ideally use Promises and async/await instead).
• Touche 9y ago
  Yes, but if the success handler throws you won't catch it. For example: promise.then(function(){ throw new Error('Oh no, not caught'); }, function(err){ }); But this will catch it: promise.then(function(){ throw new Error('Oh no!'); }).catch(function(err){ // Caught it ;) }); As will this: promise.then(function(){ throw new Error('Oh no!'); }).then(null, function(err){ // Caught it ;) }); Point being that your error handling need to be absolute last, and not paired with a success handler.