endpoints.ts

interface RequestOptions {
  authToken?: string
}

interface Fun {
  age: number;
}
const InitEndpoint = {
  get({ id }: { id: string }, options?: RequestOptions): Promise<Fun> {
    return Promise.resolve({ age: 1})
  },

  list(args: void, options: RequestOptions): Promise<Fun[]> {
    return Promise.resolve([{ age: 1}])
  }
}

async function request<T, P, O>(
  fn: (params: P, options: O) => Promise<T>,
  args?: P,
  options?: O
): Promise<T> {
  console.log('gettin it!')
  return fn(args, options)
}

async function main() {
  request(InitEndpoint.get, { id: '1' }, {}).then(x => console.log(x.age))
  const funs = await request(InitEndpoint.list)
  console.log(funs[1].age)
  await this.playbookServer.request(InitEndpoint.list)
  await request(InitEndpoint.list, { a: 5 })
  await request(InitEndpoint.list, { a: 5 }, { authToken: '6' })

  InitEndpoint.get({ id: '1' }, {})
}