app.js

/**
 * Copyright 2015-2016, 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.
 */

'use strict';

// http-parser-js addresses issues such as corrupt HTTP headers
// http://stackoverflow.com/questions/36628420/nodejs-request-hpe-invalid-header-token
process.binding('http_parser').HTTPParser = require('http-parser-js').HTTPParser;

const path = require('path');
const express = require('express');
const enforce = require('express-sslify');
const compression = require('compression');
const config = require('./config/config');
const asset = require('./lib/asset-hashing').asset;
const hbs = require('hbs');
const helpers = require('./views/helpers');
const app = express();
const bodyParser = require('body-parser');
const serveStatic = require('serve-static');
const minifyHTML = require('express-minify-html');
const libPwaIndex = require('./lib/pwa-index');

const CACHE_CONTROL_SHORT_EXPIRES = 60 * 10; // 10 minutes.
const CACHE_CONTROL_EXPIRES = 60 * 60 * 24; // 1 day.
const CACHE_CONTROL_NEVER_EXPIRE = 31536000;
const ENVIRONMENT_PRODUCTION = 'production';

if (app.get('env') === ENVIRONMENT_PRODUCTION) {
  app.use((req, res, next) => {
    if (req.path.startsWith('/tasks/')) {
      next();
    } else {
      enforce.HTTPS({trustProtoHeader: true})(req, res, next); // eslint-disable-line new-cap
    }
  });
}

app.use(compression());

app.disable('x-powered-by');
app.disable('etag');
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'hbs');
app.set('trust proxy', true);
hbs.registerPartials(path.join(__dirname, '/views/includes/'));
helpers.registerHelpers(hbs);

// Make variables available to *all* templates
hbs.localsAsTemplateData(app);
app.locals.configstring = JSON.stringify({
  /* eslint-disable camelcase */
  client_id: config.get('CLIENT_ID'),
  ga_id: config.get('GOOGLE_ANALYTICS'),
  firebase_msg_sender_id: config.get('FIREBASE_MSG_SENDER_ID')
  /* eslint-enable camelcase */
});

app.use(bodyParser.urlencoded({extended: true}));

if (app.get('env') === ENVIRONMENT_PRODUCTION) {
  app.use(minifyHTML({
    override: true,
    exception_url: false, // eslint-disable-line camelcase
    htmlMinifier: {
      removeComments: true,
      collapseWhitespace: true,
      collapseBooleanAttributes: true,
      removeAttributeQuotes: true,
      removeEmptyAttributes: true,
      minifyJS: true
    }
  }));
}

// Static files
const staticFilesMiddleware = serveStatic(path.resolve('./public'));
app.use((req, res, next) => {
  const path = req.url;
  req.url = asset.decode(path);
  let mime = serveStatic.mime.lookup(req.url);
  if (mime.match('image*') || req.url.includes('manifest.json')) {
    res.setHeader('Cache-Control', 'public, max-age=' + CACHE_CONTROL_EXPIRES);
  } else if (req.url === path) {
    res.setHeader('Cache-Control', 'public, max-age=' + CACHE_CONTROL_SHORT_EXPIRES);
  } else {
    // versioned assets don't expire
    res.setHeader('Cache-Control', 'public, max-age=' + CACHE_CONTROL_NEVER_EXPIRE);
  }
  staticFilesMiddleware(req, res, next);
});

// Make node_modules/{{module}} available at /{{module}}
['sw-toolbox', 'sw-offline-google-analytics'].forEach(module => {
  app.use(
   '/' + module,
   express.static('node_modules/' + module)
 );
});

// Middlewares
app.use(require('./middlewares'));

// Controllers
app.use(require('./controllers'));

// If no route has matched, return 404
app.use((req, res) => {
  res.status(404).render('404.hbs',
    {nonce1: req.nonce1, nonce2: req.nonce2, contentOnly: req.query.contentOnly || false});
});

// Basic error handler
app.use((err, req, res, _) => {
  console.error(err);
  if (err.status === 404) {
    res.status(404).render('404.hbs', {nonce1: req.nonce1, nonce2: req.nonce2});
  } else {
    // If our routes specified a specific response, then send that. Otherwise,
    // send a generic message so as not to leak anything.
    res.status(500).send(err || 'Something broke!');
  }
});

if (module === require.main) {
  // Start the server
  const server = app.listen(config.get('PORT'), () => {
    const port = server.address().port;
    console.log('App listening on port %s', port);
  });

  // Index all PWAs
  libPwaIndex.indexAllPwas();
}

module.exports = app;