index.ts

import {Request, Response} from 'express';

import directions from './src/directions';
import origins from './src/origins';
import places from './src/places';

/**
 * Entry point into the Functions Framework.
 * @see https://github.com/GoogleCloudPlatform/functions-framework-nodejs
 */
exports.function = (req: Request, res: Response) => {
  const paths = {
    '/directions': directions,
    '/origins': origins,
    '/places': places,
    // Default route (at the end)
    '/': () => res.send(Object.keys(paths)),
  };
  // Find the first route that matches
  for (const [path, route] of Object.entries(paths)) {
    if (req.path.startsWith(path)) {
      return route(req, res);
    }
  }

  // Allow CORS
  res.header('Access-Control-Allow-Origin', '*');
  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
  
  res.send('No path found');
};