Ember.js: Document and support {{let}} helper

[locks]

Tasks

Mandatory

• [x] Make ember-let-polyfill (@cafreeman)
• [x] Document {{let}} in the Guides. Issue. PR. (@kennethlarsen)

Optional

• [ ] Base ember-let off of ember-let-polyfill. (@cafreeman)

[chilicoder]

Does your first point mean to put some sort of check like here somewhere here?

[jamesarosen]

The built-in {{let}} helper is documented in the 3.1 API docs.

I haven't gotten it working in an Ember 3.1.0 app, but I'm not sure why yet.

[rwjblue]

It was only added in 3.2, the API docs are missing our feature flagging @category pragma perhaps?

[locks]

Apologies! I have opened a PR correcting the problem 😅.

[cafreeman]

FYI I've started work on the polyfill over here

[cafreeman]

Forgot to mention that the polyfill is completed and published to npm!

https://github.com/cafreeman/ember-let-polyfill

[ryanlabouve]

@cafreeman does this mean we can close this issue? Or should we add a checkbox to do something additional with documentation?

[cafreeman]

@ryanlabouve Yep, the only outstanding thing is that I need to get the polyfill listed correctly on ember-observer. I've requested a correction from them so hopefully it'll be fixed soon.