document-and-collection.ts

document-and-collection.ts

const videoDoc = (id: string) => ({
  get() {
    return { id }
  },
  delete() {},
})
type QueryConstraint = number

const videosCollection = (...constraints: QueryConstraint[]) => ({
  observe() {
    return { constraints }
  },
})

const videos = <
  P extends Parameters<typeof videoDoc> | Parameters<typeof videosCollection>
>(
  ...v: P
): P extends Parameters<typeof videoDoc>
  ? ReturnType<typeof videoDoc>
  : ReturnType<typeof videosCollection> => {
  return typeof v[0] === 'string' ? videoDoc(v[0]) : videosCollection(...v)
}



type X = {
  [id: string]: { get: () => string; update: () => string; delete: () => void }
  (n: number): { observe: () => number }
}

let videos: X = 'a' as any

videos['vid'].get()
videos['vid'].update()
videos(123).observe()