http2: doc fix & test for http2.connect() optional arguments

doc/api/http2.md

@@ -1388,7 +1388,7 @@ server.on('stream', (stream, headers) => {
 server.listen(80);
 ```
 
-### http2.connect(authority, options, listener)
+### http2.connect(authority[, options][, listener])
 <!-- YAML
 added: REPLACEME
 -->

test/parallel/test-http2-connect.js

@@ -0,0 +1,29 @@
+// Flags: --expose-http2
+'use strict';
+
+const { mustCall } = require('../common');
+const { doesNotThrow } = require('assert');
+const { createServer, connect } = require('http2');
+
+const server = createServer();
+server.listen(0, mustCall(() => {
+  const authority = `http://localhost:${server.address().port}`;
+  const options = {};
+  const listener = () => mustCall();
+
+  const clients = new Set();
+  doesNotThrow(() => clients.add(connect(authority)));
+  doesNotThrow(() => clients.add(connect(authority, options)));
+  doesNotThrow(() => clients.add(connect(authority, options, listener())));
+  doesNotThrow(() => clients.add(connect(authority, listener())));
+
+  for (const client of clients) {
+    client.once('connect', mustCall((headers) => {
+      client.destroy();
+      clients.delete(client);
+      if (clients.size === 0) {
+        server.close();
+      }
+    }));
+  }
+}));