token-store.js

const fs = require('fs');
const path = require('path');

// The file token.json stores the user's access and refresh tokens, and is
// created automatically when the authorization flow completes for the first
// time.
const TOKEN_PATH = "token.json";

/**
 * Reads the token from the specified path or from default path.
 * @param {String | null} token_path Path to the token file
 * @returns {Object} token object
 */
function get(token_path) {
  try {
    return JSON.parse(fs.readFileSync(
      token_path || path.resolve(__dirname, TOKEN_PATH)
    ).toString());
  } catch (error) {
    throw new Error("No token found.");
  }
}

/**
 * Stores the token in the specified path or in default path.
 * @param {Object} token Token
 * @param {String | null} token_path Path
 */
function store(token, token_path) {
  fs.writeFileSync(
    token_path || path.resolve(__dirname, TOKEN_PATH),
    JSON.stringify(token)
  );
}

module.exports = {
  get,
  store
};