test: use emitter.listenerCount() in test-http-connect

Use `emitter.listenerCount()` instead of the `length` property of the
array returned by `emitter.listeners()`.

PR-URL: #26031
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

Author: lpinca

test/parallel/test-http-connect.js

@@ -31,11 +31,11 @@ server.on('connect', common.mustCall((req, socket, firstBodyChunk) => {
   assert.strictEqual(req.url, 'google.com:443');
 
   // Make sure this socket has detached.
-  assert.strictEqual(socket.listeners('close').length, 0);
-  assert.strictEqual(socket.listeners('drain').length, 0);
-  assert.strictEqual(socket.listeners('data').length, 0);
-  assert.strictEqual(socket.listeners('end').length, 1);
-  assert.strictEqual(socket.listeners('error').length, 0);
+  assert.strictEqual(socket.listenerCount('close'), 0);
+  assert.strictEqual(socket.listenerCount('drain'), 0);
+  assert.strictEqual(socket.listenerCount('data'), 0);
+  assert.strictEqual(socket.listenerCount('end'), 1);
+  assert.strictEqual(socket.listenerCount('error'), 0);
 
   socket.write('HTTP/1.1 200 Connection established\r\n\r\n');
 
@@ -72,14 +72,14 @@ server.listen(0, common.mustCall(() => {
     assert(!socket.ondata);
     assert(!socket.onend);
     assert.strictEqual(socket._httpMessage, null);
-    assert.strictEqual(socket.listeners('connect').length, 0);
-    assert.strictEqual(socket.listeners('data').length, 0);
-    assert.strictEqual(socket.listeners('drain').length, 0);
-    assert.strictEqual(socket.listeners('end').length, 1);
-    assert.strictEqual(socket.listeners('free').length, 0);
-    assert.strictEqual(socket.listeners('close').length, 0);
-    assert.strictEqual(socket.listeners('error').length, 0);
-    assert.strictEqual(socket.listeners('agentRemove').length, 0);
+    assert.strictEqual(socket.listenerCount('connect'), 0);
+    assert.strictEqual(socket.listenerCount('data'), 0);
+    assert.strictEqual(socket.listenerCount('drain'), 0);
+    assert.strictEqual(socket.listenerCount('end'), 1);
+    assert.strictEqual(socket.listenerCount('free'), 0);
+    assert.strictEqual(socket.listenerCount('close'), 0);
+    assert.strictEqual(socket.listenerCount('error'), 0);
+    assert.strictEqual(socket.listenerCount('agentRemove'), 0);
 
     let data = firstBodyChunk.toString();
     socket.on('data', (buf) => {