google-cloud-node: Returning arrays for everything makes for awkward and confusing code

Environment details

• google-cloud-node version: 1.2.0

Steps to reproduce

1. require google-cloud
2. Do lots of operations using the API
3. Need to unpack an array with a [thing, ApiResponse] from every promise.

ex. Almost every API looks like this:

    download(options?: DownloadOptions): Promise<[Buffer]>;
    exists(): Promise<[boolean]>;
    get(): Promise<[File, ApiResponse]>;
    getMetadata(): Promise<[FileMetadata, ApiResponse]>;

but that means you end up doing [0] all over the place. The extra ApiResponse should be returned through some out of band system (ex. another argument that requests it, or a separate callback) instead of in an array with every response (and sometimes it seems there’s an array even when there is no other data returned.

I end up having to write wrappers around every Google Cloud API function like this:

const fileExists = async (file: gcs.File) => {
  return (await file.exists())[0];
};

since doing:

if (!(await file.exists())[0])) ...

is hard to read and confusing. In general all the arrays all over the API don’t feel like idiomatic Promise code. You end up leaving comments all over explaining what the arrays are about.