Ember.js Testing async action in controller - ember.js

Question

I've a controller with an action that invoke a method that do some async stuff and return a promise.
export default Ember.Controller.extend({
_upload: function() {
// return a promise
},
actions: {
save: function(item) {
this._upload(item).then(function(response) {
// Handle success
}, function(error) {
// Handle error
}
}
}
});
I would like to unit test the code under Handle success and Handle error.
In my unit test I've mocked the _uploadMethod using
controller.set("_upload", function() {
return new Ember.RSVP.Promise(function(resolve) {
resolve({name: "image1"});
});
});
And then I invoke the action and assert that the success handler has done is job
controller.send("save", "item");
assert.equal(controller.get("selected.item"), "item");
The problem is that the assertion fails because it's run before the promise is resolved and all the stuff in success handler is completed.
How can I wait the promise to resolve before the assertion is checked?

Answer 1

What if you try this instead:
controller.set("_upload", function() {
const promise = new Ember.RSVP.Promise(function(resolve) {
resolve({name: "image1"});
});
promise.then(() => Ember.run.next(() => {
assert.equal(controller.get("selected.item"), "item");
}));
return promise;
});
controller.send("save", "item");
A bit hacky way, but it might work.

Answer 2

To test async methods, you can use the test helper waitUntil to wait for the expected return of the method, like the code below.
controller.send('changeStepAsyncActionExample');
await waitUntil(() => {
return 'what you expect to the Promise resolve';
}, { timeout: 4000, timeoutMessage: 'Your timeout message' });
// If not timeout, the helper below will be executed
assert.ok(true, 'The promise was executed correctly');