Unspaghetti version of Google Spreadsheet API example code

quickstart.js

import {readFile, writeFile, mkdir} from 'mz/fs'
import readline from 'mz/readline'
import promisify from 'es6-promisify'
import google from 'googleapis'
import googleAuth from 'google-auth-library'
import clientSecret from './client_secret.json'

// If modifying these scopes, delete your previously saved credentials
// at ~/.credentials/sheets.googleapis.com-nodejs-quickstart.json
const SCOPES = ['https://www.googleapis.com/auth/spreadsheets.readonly']
const HOME = process.env.HOME || process.env.HOMEPATH || process.env.USERPROFILE
const TOKEN_DIR = `${HOME}/.credentials/`
const TOKEN_PATH = `${TOKEN_DIR}sheets.googleapis.com-nodejs-quickstart.json`

main()

async function main () {
  const oauth2Client = await authorize(clientSecret)
  listMajors(oauth2Client)
}

/**
 * Create an OAuth2 client with the given credentials, and then execute the
 * given callback function.
 *
 * @param {Object} credentials The authorization client credentials.
 */
async function authorize (credentials) {
  const clientSecret = credentials.installed.client_secret
  const clientId = credentials.installed.client_id
  const redirectUrl = credentials.installed.redirect_uris[0]
  const auth = new googleAuth()
  const oauth2Client = new auth.OAuth2(clientId, clientSecret, redirectUrl)
  const getToken = promisify(oauth2Client.getToken, oauth2Client)

  let token = {}

  // Check if we have previously stored a token.
  try {
    token = JSON.parse(await readFile(TOKEN_PATH))
  } catch (err) {
    const authUrl = oauth2Client.generateAuthUrl({
      access_type: 'offline',
      scope: SCOPES
    })
    const code = await getNewCode(authUrl)
    try {
      token = await getToken(code)
      await storeToken(token)
    } catch (err) {
      console.log('Error while trying to retrieve access token')
      throw err
    }
  }

  oauth2Client.credentials = token
  return oauth2Client
}

/**
 * Get and store new code after prompting for user authorization
 *
 * @param {string} authUrl The Auth URL generated by oauth2Client.generateAuthUrl()
 */
async function getNewCode (authUrl) {
  console.log(`Authorize this app by visiting this url: ${authUrl}`)
  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
  })
  const code = await rl.question('Enter the code from that page here: ')
  rl.close()
  return code
}

/**
 * Store token to disk be used in later program executions.
 *
 * @param {Object} token The token to store to disk.
 */
async function storeToken (token) {
  try {
    await mkdir(TOKEN_DIR)
  } catch (err) {
    if (err.code != 'EEXIST') throw err
  }
  await writeFile(TOKEN_PATH, JSON.stringify(token))
  console.log(`Token stored to ${TOKEN_PATH}`)
}

/**
 * Print the names and majors of students in a sample spreadsheet:
 * https://docs.google.com/spreadsheets/d/1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms/edit
 */
async function listMajors (auth) {
  try {
    const sheets = google.sheets('v4')
    const getValues = promisify(sheets.spreadsheets.values.get)
    const spreadsheetId = '1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms'
    const range = 'Class Data!A2:E'
    const response = await getValues({auth, spreadsheetId, range})
    const rows = response.values
    if (rows.length == 0) {
      console.log('No data found.')
      return
    }
    console.log('Name, Major:')
    for (let i = 0; i < rows.length; i++) {
      const row = rows[i]
      // Print columns A and E, which correspond to indices 0 and 4.
      console.log(`${row[0]}, ${row[4]}`)
    }
  } catch (err) {
    console.log(`The API returned an error: ${err}`)
    return
  }
}

The original code is here:
https://developers.google.com/sheets/api/quickstart/nodejs

$ npm i -S google-auth-library googleapis mz es6-promisify
$ npm i -D async-to-gen reify

Then, save the code avobe as quickstart.js and run this command:

$ node --require reify --require async-to-gen/register quickstart.js

THANKYOU!

I get compile error at line 101 (https://gist.github.com/cognitom/2300754df04df3477261ff12ee36285c#file-quickstart-js-L101). It looks like an array instead of key-value object in curly braces.