Components that do not extend LightningElement should get dev warnings for missing @api

[nolanlawson]

Follow-up to #3713 and #3758

Components that extend a non-LightningElement superclass:

export default class extends CustomSuperclass {}

... should still get dev warnings when they declare a method that is not @api-annotated. (Implemented in #3713)

This is disabled for now because it turned out to be tricky to handle superclasses that declare @api but whose subclasses do not.

[nolanlawson]

This is a little more subtle than the bug title implies – subclasses can "inherit" the warnings from their superclasses, e.g. in this case:

export default class Subclass extends Superclass () {}

export default class Superclass extends LightningElement () {
  method()
}

subclass.method() // warns

However, the following case does not cause a warning:

export default class Subclass extends Superclass () {
  method()
}

export default class Superclass extends LightningElement () {
}

subclass.method() // does not warn

In any case, we should just be consistent everywhere. Maybe this is best to tackle after #3762 since the existing behavior is pretty hard to reason about.

[mayurrkukreja]

I want to work on this issue, can it be assigned to me ? @nolanlawson

[nolanlawson]

@mayurrkukreja We don't have a process of assigning issues, but please feel free to take this up 🙂