Ember.set & Ember.setProperties fail to set properties "enumerable"

[herom]

I'm currently using Ember 2.4.3 and wanted to upgrade, but the behaviour of Ember.set and Ember.setProperties in 2.7.0 onwards seems a bit buggy to me.

To reproduce the "bad" behaviour, do the following:

const Test = Ember.Object.extend({
  myProp: null,
  didChangeMyProp: Ember.on('init', Ember.observer('myProp', function () {
    console.log('updated');
  })
});

const testInstance = Test.create();
Ember.setProperties(testInstance, {id: 3, myProp: {id: 1}});

// here, I would expect (and did get!) `['id', 'myProp']` in Ember v2.4.3
// from Ember v2.7.0 onwards, it prints `['id']`
console.log(Object.keys(testInstance));

// alternatively, if you just `set` the `myProp` property
// Ember.set(testInstance, 'myProp', {id: 1});
// the console will only print an empty array.

// however, if I don't initialize the `myProp` property in the `extend()` call, the Object.keys are set as usual

It seems, that somewhere - deep in the guts of Ember.set && Ember.setProperties the meta is declaring the property as "not enumerable"?!

I can't reproduce this "bug" at https://ember-twiddle.com as it seems to work over there, if I try these steps in the Chrome DevTools (interesstingly enough, it prints the Ember Version as 2.9.0 but if you call Ember.VERSION in the console, it prints 2.8.0 😸 )

[rwjblue]

interestingly enough, it prints the Ember Version as 2.9.0 but if you call Ember.VERSION in the console, it prints 2.8.0

This is because ember-twiddle.com itself is an Ember app (that runs Ember 2.9.0 ATM), and the app that the twiddle is creating is running in an iframe. So asking the host application Ember.VERSION reports 2.9.0, but asking the app running inside the iframe for Ember.VERSION will report whatever version is being specified in twiddle.json.

Changing the console to use the right context will fix this for you.

[rwjblue]

I suspect what is happening is that the set determines that the values are the same and does not actually set the property (because there is no work to be done).

Demo:

const Foo = Ember.Object.extend({
  prop1: null
});

let foo = Foo.create();

log('Keys:', Object.keys(foo));
foo.set('prop1', null);
log('Keys:', Object.keys(foo));
foo.set('prop1', 'value');
log('Keys:', Object.keys(foo));

[rwjblue]

I believe this is a duplicate of #14270, can you review and confirm?

[herom]

Thanks a lot for your response @rwjblue! At first I also thought it may be a duplicate of the issue you mentionend but I think it's slightly different here as the value will be set not enumerable as soon as an Ember.observer is declared for the prop1 property.

See the edited Demo of yours, where I declared an Ember.observer - the Object.keys(bar); call will always return an empty array and bar.hasOwnProperty('prop2') will return false...

So, the value is set correctly, but it's not declared enumerable when set via Object.defineProperty, I guess

[pixelhandler]

@herom I cloned your jsbin, https://jsbin.com/limuki/edit?html,js,output and set the version to 2.4.3 and do see the output that the object's property is available via hasOwnProperty. This looks like a bug to me.

[herom]

Thanks a lot @pixelhandler - I totally forgot about that (a jsbin with the "working" solution) 😃

[herom]

Just a short sumup of the different code samples in order to understand/reproduce this bug for better readability:

WORKING Demo (without Ember.observer) in Ember Canary from @rwjblue (working, does not fully reproduce the issue as it's lacking Ember.observer)

FAILING Demo (with Ember.observer) in Ember Canary from @herom (not working, fully reproduces the issue)

WORKING Demo (with Ember.observer) in Ember v2.4.3 from @pixelhandler (working, fully reproduces the issue)

[pixelhandler]

@herom @rwjblue is this still an issue, perhaps we should close or create a new reproduction of this, what do you think?

[pixelhandler]

Per our triage policy I'll close this out for now, feel free to reopen if the issue persists on the current release.

• https://github.com/emberjs/ember.js/blob/master/CONTRIBUTING.md#triaging-policy