callback for bucket.getFiles doesn't return prefixes

From the docs;

storage > bucket.getFiles > query.delimiter

[...] Objects whose names, aside from the prefix, contain delimiter will have their name truncated after the delimiter, returned in prefixes.

But then there is no reference anywhere to that "prefixes" array (?) that should contain the truncated objects.

This would be really useful if implemented, because as of today, there is not a simple way of making an object browser with folder hierarchy (like the storage explorer in the application console), which is able to list files and folders given a prefix (or inside a folder).

Related to #342

Thanks for catching this. The prefixes will be available from the apiResponse (note only will work on master, since #448 was merged):

bucket.getFiles({ /*...*/ }, function (err, files, nextQuery, apiResponse) {
  // apiResponse.prefixes
})

storage: docs for prefixes - googleapis#491

Merge pull request #506 from stephenplusplus/spp--storage-491

We put a more helpful tip in the docs. If you feel we can do better, please re-open!

In the latest version 3.2.1 prefixes can't be obtained because of the wrapping, the callback passed to the getFiles function looks like this:

cb:(err, results, nextQuery) => {
            if (err) {
                this.destroy(err);
                return;
            }
            this._nextQuery = nextQuery;
            if (this._resultsToSend !== Infinity) {
                results = results.splice(0, this._resultsToSend);
                this._resultsToSend -= results.length;
            }
            let more = true;
            for (const result of results) {
                if (this._ended) {
                    break;
                }
                more = this.push(result);
            }
            const isFinished = !this._nextQuery || this._resultsToSend < 1;
            const madeMaxCalls = ++this._requestsMade >= this._maxApiCalls;
            if (isFinished || madeMaxCalls) {
                this.end();
            }
            if (more && !this._ended) {
                setImmediate(() => this._read());
            }
            this._reading = false;
        }

So this would need a proper change, either a getPrefixes function or a different type of response.