Issue regarding precedence of helpers and properties in angle-bracket components

[iezer]

If I have helper called changeset and also a property on a component called changeset, these two code examples work differently in Ember 3.4:

1. {{my-child changeset=changeset}} Passes in the "changeset" property
2. <MyChild @changeset={{changeset}} /> Calls the "changeset" helper with no arguments.

However, 2. works the same as 1. if you're using Ember 3.3 with ember-angle-bracket-invocation-polyfill. As a result, users upgrading from Ember 3.3 with the polyfill to 3.4 might see some unexpected behavior.

This is the type of ambiguity that RFC 308 is trying to prevent but the deprecation and code mods haven't yet been implemented.

Reproduced in this twiddle

[rwjblue]

ember-template-lint includes a no-implicit-this specifically to catch this case in existing code. We should likely fix the polyfill to have consistent behavior to the real feature (always calling the helper), would you mind making an issue (or even a failing test PR)?

[iezer]

I've opened ember-polyfills/ember-angle-bracket-invocation-polyfill#50 and when I have time I'll write the failing test.

[chancancode]

Unfortunately, this is probably "working as intended" (a.k.a. "probably too late to fix" now). RFC 432 propose to deprecate the second behavior. I would love to be proven wrong (about the "probably too late" part), but what I proposed in the RFC is probably the best we can do.

[chancancode]

(the polyfill should be updated to match the Ember behavior though)