Code provider facilitates self closing window

[langsamu]

Follows up from #37. Specifically implements suggestion in #37 (comment).

Defined in provider interface. We want to return both

• a string value and
• a dispose method:
  

  reactive-authentication/src/CodeProvider.ts

  Line 3 in e6dd495

  getCode(authorizationUri: URL, signal: AbortSignal): Promise<Disposable & { get value(): string }>

Used in code provider.

• Value is the actual code,
• dispose is closing the popup:
  

  reactive-authentication/src/AuthorizationCodeFlow.ts

  Line 218 in e6dd495

  return new ValueWithCleanup(await responseFromPopup, () => this.#authorizationWindow?.close())

[jeswr]

It is possible that for dispose to be invoked before the code flow has been completed - thereby requiring #cancel to be called here?

[langsamu]

Yes, it is possible for dispose to be called at any point. Giving the caller this responsibility is a risk to be alleviated by documentation.

Whether #cancel needs to be called or not, I don't know yet. I will need to iterate this.

[jeswr]

I was expecting AuthorizationCodeFlow to be the disposable class.

Specifically, I would expect the cleanup, cancel and Symbol.dispose methods to all belong to the same class.

What is the reason for this approach?

[langsamu]

AuthorizationCodeFlow is an HTML element. Its life-cycle is bound to the DOM.
It is also an implementation of a CodeProvider, so it knows how to return something that is both disposable and carries a string value.

This implementation detail, ValueWithCleanup, is just a local container for the above (Disposable & { get value(): string }). It contains both the string value (code from Authorization Code flow) and the cleanup method (lambda that closes the authorization window.