Function makeSocket

src/cmap/connect.ts:378–474

(options: MakeConnectionOptions)

}

export async function makeSocket(options: MakeConnectionOptions): Promise<Stream> {
  const useTLS = options.tls ?? false;
  const connectTimeoutMS = options.connectTimeoutMS ?? 30000;
  const existingSocket = options.existingSocket;
  const keepAliveInitialDelay =
    options.keepAliveInitialDelay ?? DEFAULT_KEEP_ALIVE_INITIAL_DELAY_MS;
  const noDelay = options.noDelay ?? true;

  let socket: Stream;

  if (options.proxyHost != null) {
    // Currently, only Socks5 is supported.
    return await makeSocks5Connection({
      ...options,
      connectTimeoutMS // Should always be present for Socks5
    });
  }

  if (useTLS) {
    const tlsSocket = tls.connect(parseSslOptions(options));
    if (typeof tlsSocket.disableRenegotiation === 'function') {
      tlsSocket.disableRenegotiation();
    }
    socket = tlsSocket;
  } else if (existingSocket) {
    // In the TLS case, parseSslOptions() sets options.socket to existingSocket,
    // so we only need to handle the non-TLS case here (where existingSocket
    // gives us all we need out of the box).
    socket = existingSocket;
  } else {
    socket = net.createConnection(parseConnectOptions(options));
  }

  // Explicit setKeepAlive/setNoDelay are required because tls.connect() silently
  // ignores these constructor options due to a Node.js bug.
  // See: https://github.com/nodejs/node/issues/62003
  // TODO(NODE-7474): remove this fix once the underlying Node.js issue is resolved.
  socket.setKeepAlive(true, keepAliveInitialDelay);
  socket.setNoDelay(noDelay);
  socket.setTimeout(connectTimeoutMS);

  let cancellationHandler: ((err: Error) => void) | null = null;

  const { promise: connectedSocket, resolve, reject } = promiseWithResolvers<Stream>();
  if (existingSocket) {
    resolve(socket);
  } else {
    const start = performance.now();
    const connectEvent = useTLS ? 'secureConnect' : 'connect';
    socket
      .once(connectEvent, () => resolve(socket))
      .once('error', cause =>
        reject(new MongoNetworkError(MongoError.buildErrorMessage(cause), { cause }))
      )
      .once('timeout', () => {
        reject(
          new MongoNetworkTimeoutError(
            `Socket '${connectEvent}' timed out after ${(performance.now() - start) | 0}ms (connectTimeoutMS: ${connectTimeoutMS})`