net: allow missing callback for Socket.connect

Arguments of Socket.prototype.connect should be also normalized,
causing error when called without callback.

Changed Socket.prototype.connect's code same as net.connect and added
test.

Fixes: https://github.com/nodejs/node/issues/11761
PR-URL: https://github.com/nodejs/node/pull/11762
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/test/parallel/test-net-socket-connect-without-cb.js b/test/parallel/test-net-socket-connect-without-cb.js
new file mode 100644
index 00000000000..468b29a3a48
--- /dev/null
+++ b/test/parallel/test-net-socket-connect-without-cb.js
@@ -0,0 +1,20 @@
+'use strict';
+const common = require('../common');
+
+// This test ensures that socket.connect can be called without callback
+// which is optional.
+
+const net = require('net');
+
+const server = net.createServer(common.mustCall(function(conn) {
+  conn.end();
+  server.close();
+})).listen(0, common.mustCall(function() {
+  const client = new net.Socket();
+
+  client.on('connect', common.mustCall(function() {
+    client.end();
+  }));
+
+  client.connect(server.address());
+}));