3.5.0 rendering reggression

[ilucin]

Found a weird rendering engine regression in 3.5.0 release. The issue is that the DOM isn't updated properly on state change on the component.

I have this in my component's template.hbs:

{{#if isSubmitting}}
  <div class="spinner"></div>
{{/if}}

and in component.js:

isSubmitting: reads('model.isSubmitting')

isSubmitting goes from initial false value to true and to false again but in ember 3.5.0 the last state change isn't reflected in the DOM - the spinner stays visible. Here are two short videos proving the component has the correct state but there's a rendering issue in the 3.5.0 version:

• Ember 3.5.0 -> https://monosnap.com/file/HmoCqreHdO6U9H3OZxP4KyMq6CPrMM
• Ember 3.4.5 -> https://monosnap.com/file/rqXTWLBPWIxHVPLyDRQq0ItcMjfkIq

The only difference between the two videos is that I've run:

yarn add ember@3.4.5; 
ember deploy;

In the video, there's a v($0) function in the global scope that does this:

window.v = (el) => owner.lookup('-view-registry:main')[el.id];

... so I'm actually checking the state of that component instance.

Few things that might be relevant here:

• the issue is only happening on production build
• the component I'm talking about is rendered as a contextual component whereas model is a contextual property -> I'm suspecting this is pretty important
• I've tried the 3.6.0-beta.1 build but it's completely broken, cannot even run the app
• I have {"jquery-integration": false} in my optional-features.json
• ember-cli@3.4.3, ember-data@3.4.2, ember-engines@0.5.23

Anybody has an idea what might have happened in the last release?

[rwjblue]

Hmm, nothing jumps out at me here. Can you tell me more about your setup? What do the components look like (ts or js, decorators, etc)? Do you have any deprecations/assertions in the debug build? Might be hard to debug this without a reproduction that we can dig into (and creating a repro may help us identify what is wrong), would you mind trying to re-recreate the issue in a demo repo?

[ilucin]

@rwjblue I've tracked it down. It has something to do with using {defineProperty} from '@ember/object' in production build. Here's a minimal repo reproducing the bug.

This is the output after clicking "boom" when I run it in development:

A: 1,2,3
B: 1,2,3

.. and after ember build --environment=production:

A: 1,2,3
B: 1,2

It works as expected in ember@3.4.5.

[mschorsch]

Is there any progress on this issue? This bug prevents us from upgrading to Ember 3.5.1.

[chancancode]

I think this is a dup of #17243 and is fixed by #17487 (landed in 3.8 beta)