Google-api-nodejs-client: appDataFolder files unreachable

[DevinBayly]

I'm attempting to access an appDataFolder with the node client library, but the res.files is undefined each time. I have separately confirmed using a different credential, and client for this app that there are in fact files in the appDataFolder successfully uploaded with the node client. Am I not query the drive correctly? Has anyone had success doing this recently using the node client?

server.js code (nodeversions tested 32&27)

const fs = require('fs');
const readline = require('readline');
const {google} = require('googleapis');

// If modifying these scopes, delete credentials.json.
const SCOPES = ['https://www.googleapis.com/auth/drive.appdata'];
const TOKEN_PATH = 'token.json';


let readAppFolder=(auth) => {
    const  drive = google.drive({version:'v3',auth})
    drive.files.list({
      spaces: 'appDataFolder',
      fields: 'nextPageToken, files(id, name)',
      pageSize: 10
    }, function (err, res) {
      if (err) {
        // Handle error
        console.error(err);
      } else {
        res.files.forEach(function (file) {
          console.log('Found file:', file.name, file.id);
        });
      }
    });

}

let writeAppFile = (auth) => {
    var fileMetadata = {
      'name': 'config.json',
        "parents":["appDataFolder"],
    };
    var media = {
      mimeType: 'application/octet-stream',
      body: fs.createReadStream('./test.json')
    };
    const  drive = google.drive({version:'v3',auth})
    drive.files.create({
      resource: fileMetadata,
      media: media,
      fields: 'id'
    }, function (err, file) {
      if (err) {
        // Handle error
        console.error(err);
      } else {
        console.log('Folder Id:', file.id);
      }
    });
    readAppFolder(auth)
}

let addFolder=(name) => {
    let fMet = {
        'name':name,
        'mimeType':'application/vnd.google-apps.folder',
    }

    return (auth) => {
        const drive = google.drive({version:'v3',auth})
        drive.files.create({
            resource:fMet,
            fields:'id',
        },(err,file) => {
            if (err) console.log(err)
            else console.log(`File ID is ${file.id}`)
        })
    }
}
// Load client secrets from a local file.
fs.readFile('credentials.json', (err, content) => {
  if (err) return console.log('Error loading client secret file:', err);
  // Authorize a client with credentials, then call the Google Drive API.
  let namedFolder = addFolder('folder_test')
  authorize(JSON.parse(content), readAppFolder);
});

/**
 * Create an OAuth2 client with the given credentials, and then execute the
 * given callback function.
 * @param {Object} credentials The authorization client credentials.
 * @param {function} callback The callback to call with the authorized client.
 */
function authorize(credentials, callback) {
  const {client_secret, client_id, redirect_uris} = credentials.installed;
  const oAuth2Client = new google.auth.OAuth2(
      client_id, client_secret, redirect_uris[0]);

  // Check if we have previously stored a token.
  fs.readFile(TOKEN_PATH, (err, token) => {
    if (err) return getAccessToken(oAuth2Client, callback);
    oAuth2Client.setCredentials(JSON.parse(token));
    callback(oAuth2Client);
  });
}

/**
 * Get and store new token after prompting for user authorization, and then
 * execute the given callback with the authorized OAuth2 client.
 * @param {google.auth.OAuth2} oAuth2Client The OAuth2 client to get token for.
 * @param {getEventsCallback} callback The callback for the authorized client.
 */
function getAccessToken(oAuth2Client, callback) {
  const authUrl = oAuth2Client.generateAuthUrl({
    access_type: 'offline',
    scope: SCOPES,
  });
  console.log('Authorize this app by visiting this url:', authUrl);
  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
  });
  rl.question('Enter the code from that page here: ', (code) => {
    rl.close();
    oAuth2Client.getToken(code, (err, token) => {
      if (err) return callback(err);
      oAuth2Client.setCredentials(token);
      // Store the token to disk for later program executions
      fs.writeFile(TOKEN_PATH, JSON.stringify(token), (err) => {
        if (err) console.error(err);
        console.log('Token stored to', TOKEN_PATH);
      });
      callback(oAuth2Client);
    });
  });
}

/**
 * Lists the names and IDs of up to 10 files.
 * @param {google.auth.OAuth2} auth An authorized OAuth2 client.
 */
function listFiles(auth) {
  const drive = google.drive({version: 'v3', auth});
  drive.files.list({
    pageSize: 10,
    fields: 'nextPageToken, files(id, name)',
  }, (err, res) => {
    if (err) return console.log('The API returned an error: ' + err);
    const files = res.data.files;
    if (files.length) {
      console.log('Files:');
      files.map((file) => {
        console.log(`${file.name} (${file.id})`);
      });
    } else {
      console.log('No files found.');
    }
  });
}

error message

(node:5349) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): TypeError: Cannot read property 'forEach' of undefined
(node:5349) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Thanks!

[JustinBeckwith]

Greetings! You likely want res.data.files :) Can you give that a shot?

[DevinBayly]

Wow, that's totally what I did in the non appdata file lister. Seems consistent, and also works, but I'd really appreciate if the documentation suggests this instead of the broken code. Thanks for looking into this!