[GLIMMER] Prevent auto-run assertion for objects not rendered.

[rwjblue]

Prior to this change any Ember.set done after any rendering has been done during tests will trigger the auto-run assertion.

This change prevents the auto-run assertion when a given object has not been used in rendering process.

[rwjblue]

@wycats / @krisselden - Would you mind reviewing this? If this is not correct, can you explain what I am forgetting/missing?

[rwjblue]

FWIW, this fixes the errors under ember-alpha for ember-data (identified in emberjs/data#4503).

[chancancode]

I am 90% sure that this is fine, in fact we perhaps don't even need to bump CURRENT_TAG anymore (since nothing in the system uses it); however, I would appreciate more eyes and brains on this

[krisselden]

I have doubts, i'd like to know the motivation

[rwjblue]

There are any number of things that you may be doing that trigger a propertyDidChange event that have nothing to do with rendering.

One example is a simply creating an array proxy (new Ember.ArrayProxy({ content: []});), before this PR this would trigger the auto-run assertion if any views had been rendered (demo here). That seems quite wild (and potentially breaking) to me.

[krisselden]

"There are any number of things that you may be doing that trigger a propertyDidChange event that have nothing to do with rendering."

This is a given, that is how it works now.

[rwjblue]

I'm not sure I follow.

On current alpha builds (before the change in this PR), anything that calls propertyDidChange (regardless of if it were used in the templating system) is going to trigger the auto-run assertion in test mode.

This is definitely a change from current beta. I am unsure if it will affect folks trying to test glimmer or not...

[krisselden]

After thinking about it, if the view layer puts the tag onto anything it renders and CURRENT_TAG is unused by the view system, and observers then are used behind the tagged object going from view system to object layer, I think this change is good, but it should return early, not dirty CURRENT_TAG and we have to make sure we have no more CURRENT_TAG usage in the view layer.

[rwjblue]

Replaced by #14093.

[homu]

☔ The latest upstream changes (presumably #14093) made this pull request unmergeable. Please resolve the merge conflicts.