Update @firebase/database-types

[DimitarNestorov]

Describe your environment

• Operating System version: macOS 10.14.2
• Browser version: N/A
• Firebase SDK version: N/A
• Firebase Product: database

Describe the problem

ThenableRefrence doesn't have catch, while Reference does.

firebase-js-sdk/packages/database-types/index.d.ts

Line 101 in c6357fb

push(value?: any, onComplete?: (a: Error | null) => any): ThenableReference;

firebase-js-sdk/packages/database/src/api/Reference.ts

Line 316 in c6357fb

push(value?: any, onComplete?: (a: Error | null) => void): Reference {

Reason for issue: firebase/firebase-admin-node#433

[mikelehen]

Just to be clear, per firebase/firebase-admin-node#433 I think the proposal here is that we make ThenableReference extend Promise instead of PromiseLike.

[DimitarNestorov]

Out of curiosity, why does @firebase/database-types even exist? Why not just generate the definitions from @firebase/database?

[mikelehen]

@DimitarNestorov I think it's mostly so we can carefully control our public surface area. There may be properties / methods on our implementation classes that are "public" for the sake of our own implementation details, but which aren't actually part of our supported API surface area for third-parties to use. So we use the d.ts files to clearly define (and document) our public APIs. Additionally, any changes to our public surface area are carefully reviewed and subject to extra processes, etc. so having them live in a dedicated file is helpful separation.

[mikelehen]

I've created a PR which I think should address this. #1451