Add AppMetadata interface, declared unimplemented methods to ProjectManagement

[TrCaM]

Description

Extend project scoped operations in the NodeJS Admin SDK with the addition of AppMetadata interface and 2 new methods into ProjectManagement class (unimplemented):

• listAppMetadata() : Lists summary of all apps belongs to the project
• setDisplayName(): Update display name of the project

In this pull request

• Declare AppMetadata interface in AppMetadata.ts
• Move AndroidAppMetadata and IosAppMetadata declaration into AppMetadata.ts
• Make AndroidAppMetadata and IosAppMetadata inherited from AppMetadata
• Update existing code and tests to match the change
• Update types in index.d.ts (readonly will be added in a separate pr)
• Declare listAppMetadata() and setDisplayName() which currently just throw errors.

[TrCaM]

@hiranya911, I have a question for AppMetadata - Should we simply add the platform field to AndroidAppMetadata with the field's type requiring it to be set to ANDROID? Or should we convert AndroidAppMetadata to a class, and give it a constructor like below?

interface AppMetadata {
  public readonly appId: string;
  public readonly displayName?: string;
  public readonly platform: AppPlatform;
}

class AndroidAppMetadata implements AppMetadata {
  constructor(
      appId: string,
      displayName: string,
      readonly resourceName: string,
      readonly projectId: string,
      readonly packageName: string) {
    super(appId, displayName, AppPlatform.ANDROID);
  }
}

And would either of those options be considered a breaking change in the Admin SDK? There should be no reason for users of the SDK to ever construct an instance of AndroidAppMetadata themselves, but our public interface makes it possible to do so.

[hiranya911]

Is there an API proposal for these changes?

I don't think what you've proposed above will actually work. Because AppMetadata is an interface, you cannot initialize its properties in AndroidAppMetadata by calling super(). You probably need to make AppMetadata a class for that to work.

[nbegley]

@hiranya911, I'd like to re-pose @TrCaM's question after replacing interface AppMetadata with class AppMetadata. I'll send you a link to the private API proposal.

Basically, the question is "Can we change AndroidAppMetadata and IosAppMetadata from interfaces to "classes that inherit from AppMetadata" without that being a breaking change?

[hiranya911]

Looks pretty good. Just a couple of nits.

As for declaring the platform field, I like how it's currently done in the PR. It doesn't require us to make any drastic changes (some of which could be potentially breaking for some users), and gives enough type safety for the problem at hand.

[hiranya911]

LGTM.

Please make sure @nbegley signs off on this before merging.

[nbegley]

LGTM, with a small requested change.

[nbegley]

LGTM, thanks Tri!