server.js

  1. const url = require('url');
  2. const http = require('http');
  3. const body = require('body');
  4. const npmlog = require('npmlog');
  5. const dummy = require('dummy-object');
  7. /**
  8.  * Takes HTTP requests
  9.  *
  10.  * Example (in the main script):
  11.  * ```
  12.  * const server = new Server(somebot, someotherbot);
  13.  * server.listen(80, 'localhost');
  14.  * ```
  15.  */
  16. class Server {
  17.   /**
  18.    * @param {Function[]} [bots]        Bots whose handle method will be called
  19.    *                                   on incoming requests
  20.    * @param {object}     [options]
  21.    * @param {object}     [options.log] npmlog-like logger; pass null to disable
  22.    */
  23.   constructor(bots = [], { log } = {}) {
  24.     this.bots = bots;
  25.     if (bots) {
  26.       for (const bot of bots) {
  27.         bot.setServer(this);
  28.       }
  29.     }
  31.     if (log === null) {
  32.       this.log = dummy;
  33.     } else {
  34.       this.log = log || npmlog;
  35.     }
  37.     // Creating HTTP server. Data is handled by this.request
  38.     this.server = http.createServer((req, res) => this.request(req, res));
  39.   }
  41.   /**
  42.    * Adds bots whose handle functions are called on HTTP requests
  43.    *
  44.    * @param {Bot} bot
  45.    */
  46.   addBot(bot) {
  47.     this.bots.push(bot);
  48.     bot.server = this;
  49.   }
  51.   /**
  52.    * Executes the HTTP Server's listen method
  53.    *
  54.    * @param {number} port Port to listen on
  55.    * @param {string} host Hostname for the server
  56.    *
  57.    * @see https://nodejs.org/api/http.html
  58.    */
  59.   listen(...args) {
  60.     this.log.http('bot', `Server on app ${process.pid} started`);
  61.     this.server.listen(...args);
  62.   }
  65.   /**
  66.    * Receives HTTP requests from the API
  67.    *
  68.    * @param {IncomingMessage} req Request
  69.    * @param {ServerResponse}  res Response
  70.    */
  71.   request(req, res) {
  72.     if (req.method === 'POST') {
  73.       const parts = url.parse(req.url, true);
  74.       const route = parts.pathname;
  75.       const passedUrl = parts.query && parts.query.url ? parts.query.url : '';
  77.       this.log.http('server', `Request on route '${route}'`);
  79.       body(req, (err, parsed) => {
  80.         if (err) {
  81.           this.log.error('server', 'Body parser error', err);
  82.           return;
  83.         }
  84.         for (const bot of this.bots) {
  85.           bot.handle(parsed, passedUrl, route, res);
  86.         }
  87.       });
  88.     } else {
  89.       res.writeHead(400, { 'Content-Type': 'text/plain' });
  90.       res.end('Nothing to do here!');
  91.     }
  92.   }
  93. }
  95. module.exports = Server;