shim.js

/**
 * Copyright 2018, Google, Inc.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

const httpShim = PORT => {
  // [START functions_testing_shim_http]
  // Import dependencies
  const gcfCode = require('./index.js');
  const express = require('express');

  // TODO(developer): specify the port to use
  // const PORT = 3000;

  // Start local HTTP server
  const app = express();
  const server = require(`http`).createServer(app);
  server.on('connection', socket => socket.unref());
  server.listen(PORT);

  // Register HTTP handlers
  Object.keys(gcfCode).forEach(gcfFn => {
    // Handle a single HTTP request
    const handler = (req, res) => {
      gcfCode[gcfFn](req, res);
      server.close();
    };

    app.get(`/${gcfFn}`, handler);
    app.post(`/${gcfFn}`, handler);
  });
  // [END functions_testing_shim_http]
};

const pubsubShim = (gcfFn, topicName, subscriptionName) => {
  // [START functions_testing_shim_pubsub]
  // Import dependencies
  const {PubSub} = require('@google-cloud/pubsub');
  const pubsub = new PubSub();

  // TODO(developer): specify a function to test
  // const gcfCode = require('./index.js');
  // const gcfFn = gcfCode.YOUR_FUNCTION;

  // TODO(developer): specify an existing topic and subscription to use
  // const topicName = process.env.TOPIC || 'YOUR_TOPIC';
  // const subscriptionName = process.env.SUBSCRIPTION || 'YOUR_SUBSCRIPTION';

  // Subscribe to Pub/Sub topic
  const subscription = pubsub.topic(topicName).subscription(subscriptionName);

  // Handle a single Pub/Sub message
  const messageHandler = msg => {
    gcfFn({data: msg}, () => {
      msg.ack();
      subscription.removeListener(`message`, messageHandler);
    });
  };
  subscription.on(`message`, messageHandler);
  // [END functions_testing_shim_pubsub]
};

const storageShim = (gcfFn, bucketName, topicName, subscriptionName) => {
  // [START functions_testing_shim_storage]
  // Import dependencies
  const Pubsub = require('@google-cloud/pubsub');
  const {Storage} = require(`@google-cloud/storage`);
  const pubsub = Pubsub();
  const storage = new Storage();

  // TODO(developer): specify a function to test
  // const gcfCode = require('./index.js');
  // const gcfFn = gcfCode.YOUR_FUNCTION;

  // TODO(developer): specify a Cloud Storage bucket to monitor
  // const bucketName = 'YOUR_GCS_BUCKET'

  // TODO(developer): specify an existing topic and subscription to use
  // const topicName = process.env.TOPIC || 'YOUR_TOPIC';
  // const subscriptionName = process.env.SUBSCRIPTION || 'YOUR_SUBSCRIPTION';

  // Create notification on target bucket
  // Further info: https://cloud.google.com/storage/docs/reporting-changes
  const bucket = storage.bucket(bucketName);
  return bucket
    .createNotification(topicName)
    .then(data => data[0])
    .then(
      notification =>
        new Promise(resolve => {
          // Subscribe to Pub/Sub topic
          const subscription = pubsub
            .topic(topicName)
            .subscription(subscriptionName);

          // Handle a single Pub/Sub message
          const messageHandler = msg => {
            const data = JSON.parse(Buffer.from(msg.data, 'base64').toString());
            gcfFn({data: data}, () => {
              msg.ack();
              subscription.removeListener(`message`, messageHandler);
              resolve(notification);
            });
          };
          subscription.on(`message`, messageHandler);
        })
    )
    .then(notification => notification.delete()); // Delete notification
  // [END functions_testing_shim_storage]
};

const gcfCodeGlobal = require('./index.js');
require(`yargs`) // eslint-disable-line
  .demandCommand(1)
  .command('http <port>', 'HTTP-triggered-function shim', {}, opts =>
    httpShim(opts.port)
  )
  .command(
    'pubsub <functionName> <topic> <subscription>',
    'PubSub-triggered-function shim',
    {},
    opts =>
      pubsubShim(
        gcfCodeGlobal[opts.functionName],
        opts.topic,
        opts.subscription
      )
  )
  .command(
    'storage <functionName> <bucket> <topic> <subscription>',
    'Storage-triggered-function shim',
    {},
    opts =>
      storageShim(
        gcfCodeGlobal[opts.functionName],
        opts.bucket,
        opts.topic,
        opts.subscription
      )
  )
  .wrap(120)
  .help()
  .strict().argv;