WithBoundArgs and new {{component}} typing

[nwhittaker]

The migration notes recommend typing {{component}} as ComponentLike<SomeChildComponentSignature>.¹

The WithBoundArgs doc wraps the original component typing: WithBoundArgs<typeof SomeBanner, 'kind'>.²

I would've thought WithBoundArgs would wrap the new typing: WithBoundArgs<ComponentLike<SomeBannerSignature>, 'kind'>. Does it matter either way?

Footnotes

1. https://typed-ember.gitbook.io/glint/troubleshooting/migrating#component-typing ↩

2. https://typed-ember.gitbook.io/glint/using-glint/glint-types#withboundargs-and-withboundpositionals ↩

[dfreeman]

WithBoundArgs is happy to accept any ComponentLike type as input, and its behavior should be essentially identical whether you give it typeof SomeBanner or ComponentLike<SomeBannerSignature>.

The difference is that typeof SomeBanner promises much more than just the ComponentLike bit of its type—that type includes every other piece of SomeBanner's type, including things like private fields, its inheritance hierarchy, etc.

So if you write typeof SomeBanner in your signature, you're including all of those extra bits as part of your public interface. And that's fine if the actual SomeBanner value is what you're passing to fulfill that type. As the migration doc you linked points out, though, the {{component}} helper doesn't return the original class with all its fine details. The object it gives back is only usable as an opaque component-y value: hence, ComponentLike.