Method attach

packages/socket.io/lib/index.ts:482–516

* Attaches socket.io to a server or port. * * @param srv - server or port * @param opts - options passed to engine.io * @return self

(
    srv: TServerInstance | number,
    opts: Partial<ServerOptions> = {},
  )

   * @return self
   */
  public attach(
    srv: TServerInstance | number,
    opts: Partial<ServerOptions> = {},
  ): this {
    if (class="st">"function" == typeof srv) {
      const msg =
        class="st">"You are trying to attach socket.io to an express " +
        class="st">"request handler function. Please pass a http.Server instance.";
      throw new Error(msg);
    }

    class="cm">// handle a port as a string
    if (Number(srv) == srv) {
      srv = Number(srv);
    }

    if (class="st">"number" == typeof srv) {
      debug(class="st">"creating http server and binding to %d", srv);
      const port = srv;
      srv = createServer((_req, res) => {
        res.writeHead(404);
        res.end();
      });
      srv.listen(port);
    }

    class="cm">// merge the options passed to the Socket.IO server
    Object.assign(opts, this.opts);
    class="cm">// set engine.io path to `/socket.io`
    opts.path = opts.path || this._path;

    this.initEngine(srv, opts);

    return this;
  }

  /**
   * Attaches socket.io to a uWebSockets.js app.