Promises don't reject when the same promise is returned from a .then resolve

[wescravens]

Example:

var firebase = new Firebase(...)
var baseRef = newFireproof(firebase);

function addPost (post) {
  var newPostRef = baseRef.child('post').push(post);
  newPostRef.then(function () {
    newPostRef.child('childRef').set('value', 'something');
    return newPostRef; // If promise and x refer to the same object, reject promise with a TypeError as the reason.
  });
}

addPost({...}).then(function (newPostRef) {
  // use newPostRef
});

[wescravens]

It is entirely possible that this issue could be with the Babel Promise polyfill since that's what I'm using for Promises. I will try to isolate whether that is the case.

[wescravens]

I seems that Babel handles this correctly so the issue is likely because of .push returning a ref with a .then method and being handled as thenable according to A+. Since the ref contains the promise, but is not identical to the promise object, it throws off the promise resolution procedure. My recommendation would be for the return from push to return the ref with a promise property containing the .then method similar to how ngResource works.

var newRef = ref.push({...});
console.log(newRef);
/*
{
  _ref: Firebase {},
  promise: Promise {
    then: function (ok, fail) {...}
  }
}
*/

Example

[goldibex]

Thanks @wescravens. Could you propose an approach that wouldn't break existing code that depends on the current behavior of ref.push()?

[wescravens]

The only solution I have that doesn't break existing functionality is described in issue #21