refactor: dedupe waitForConnectPromise logic

Author: vkarpov15

lib/connection.js

@@ -830,17 +830,18 @@ Connection.prototype._waitForConnect = async function _waitForConnect(noTimeout)
     let timedOut = false;
     // The element that this function pushes onto `_queue`, stored to make it easy to remove later
     const queueElement = {};
+
+    // Mongoose executes all elements in `_queue` when initial connection succeeds in `onOpen()`.
+    const waitForConnectPromise = new Promise(resolve => {
+      queueElement.fn = resolve;
+      this._queue.push(queueElement);
+    });
+
     if (noTimeout) {
-      await new Promise(resolve => {
-        queueElement.fn = resolve;
-        this._queue.push(queueElement);
-      });
+      await waitForConnectPromise;
     } else {
       await Promise.race([
-        new Promise(resolve => {
-          queueElement.fn = resolve;
-          this._queue.push(queueElement);
-        }),
+        waitForConnectPromise,
         new Promise(resolve => {
           timeout = setTimeout(
             () => {