Add type-information for the `cached` decorator

[boris-petrov]

Which package(s) does this enhancement pertain to?

• [ ] @types/ember
• [ ] @types/ember__string
• [ ] @types/ember__polyfills
• [ ] @types/ember__object
• [ ] @types/ember__utils
• [ ] @types/ember__array
• [ ] @types/ember__engine
• [ ] @types/ember__debug
• [ ] @types/ember__runloop
• [ ] @types/ember__error
• [ ] @types/ember__controller
• [ ] @types/ember__component
• [ ] @types/ember__routing
• [ ] @types/ember__application
• [ ] @types/ember__test
• [ ] @types/ember__test-helpers
• [ ] @types/ember__service
• [ ] @types/ember-data
• [ ] @types/rsvp
• [x] Other
• [ ] I don't know

Please write a user story for this feature

import { cached } from '@glimmer/tracking'; leads to Module '"@glimmer/tracking"' has no exported member 'cached'.. As of Ember 4 the cached decorator is available by default.

I currently work-around that issue by adding:

declare module '@glimmer/tracking' {
  export const cached: PropertyDecorator;
}

[chriskrycho]

Thanks for writing this up, @boris-petrov. As per the usual flow, we need it documented in Ember itself, and then a PR to DefinitelyTyped will be very welcome and we'll merge it!

[andreyfel]

It is in the docs since Ember 4.5: https://api.emberjs.com/ember/4.5/functions/@glimmer%2Ftracking/cached

[dfreeman]

Just a note for posterity here, @glimmer/tracking's types aren't managed in DT—it ships its own declarations, and there's an issue over their noting the missing export: https://github.com/glimmerjs/glimmer.js/issues/408

[boris-petrov]

Thanks, @dfreeman! In that case, I guess this one can be closed! :)