Ember uses deprecated features

[kanongil]

The events.inherited-function-listeners deprecation triggers from within ember itself.

The triggered method:

ember.js/packages/@ember/-internals/runtime/lib/mixins/-proxy.js

Lines 21 to 27 in a7d861b

	function contentPropertyDidChange(content, contentKey) {
	let key = contentKey.slice(8); // remove "content."
	if (key in this) {
	return;
	} // if shadowed in proxy
	notifyPropertyChange(this, key);
	}

[pzuraq]

Listeners are inherited lazily, so there's no way for us to know ahead of time that they will cause a deprecation. When we first notify a property that causes the listener to fire, we collapse the inheritance tree and encounter the issue, throwing the deprecation message.

You should look through your code to see where you are doing addListener or addObserver with a function to see where this might be coming from. Alternatively, you can place a breakpoint at the deprecation itself, and log the function there, it should link you back to the actual function, which should help you find where it is being added.

[kanongil]

@pzuraq It is not my code:

ember.js/packages/@ember/-internals/runtime/lib/mixins/-proxy.js

Line 75 in a7d861b

addObserver(this, contentKey, null, contentPropertyDidChange);

[pzuraq]

If that's the deprecation message you are seeing, I believe this is a different listener that is being triggered by that observer. Those observers are only ever added to instances, the willWatchProperty function is never called on a prototype, and could not trigger this message.

If you still need to debug this, please put a breakpoint at the location of the deprecation and log the function, so we can be sure.

[kanongil]

It's an ember issue, replicated with this command:

Ember.ObjectProxy.extend({ a: function () {}.observes('b') }).create()

[pzuraq]

That's not supported anymore, and trying that out locally I get a different deprecation:

DEPRECATION: Function prototype extensions have been deprecated, please migrate from function(){}.observes('foo') to observer('foo', function() {}). [deprecation id: function-prototype-extensions.observes]

I don't get the deprecation you're describing.

[pzuraq]

My mistake actually, I was able to reproduce this after switching to an older version of Ember. You are correct, this is a bug, will submit a fix shortly. Sorry again for the confusion, it's been a long week!

[BillyRayPreachersSon]

I'm working though upgrading our app from 3.4 LTS to 3.8 LTS. I've removed 7500+ of the events.inherited-function-listeners deprecation warnings from our CI test logs, but are left with 8, and they all come from the same internal code in @ember/-internals/runtime/lib/mixins/-proxy.js.

We're using ember-cli 3.8.3 and ember-source 3.8.0.

Will this fix be backported, so that 3.8 LTS users get the benefit?

Thanks!

[rwjblue]

[email protected] already includes this fix, please update 😸

[BillyRayPreachersSon]

[email protected] already includes this fix, please update 😸

Perfect, down to 0 warnings (of that type, at least). Thanks!