From bac9ba4f8a1ad4da956e4be47b57e8fd43ebce0f Mon Sep 17 00:00:00 2001
From: Rongjian Zhang <pd4d10@gmail.com>
Date: Thu, 6 May 2021 14:41:55 +0800
Subject: [PATCH] dgram: extract cluster lazy loading method to make it
 testable

PR-URL: https://github.com/nodejs/node/pull/38563
Refs: https://coverage.nodejs.org/coverage-26e318a321a872bc/lib/dgram.js.html#L202
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
---
 lib/dgram.js | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/lib/dgram.js b/lib/dgram.js
index d7cecc5ba9d552..21654f66712be0 100644
--- a/lib/dgram.js
+++ b/lib/dgram.js
@@ -85,7 +85,11 @@ const RECV_BUFFER = true;
 const SEND_BUFFER = false;
 
 // Lazily loaded
-let cluster = null;
+let _cluster = null;
+function lazyLoadCluster() {
+  if (!_cluster) _cluster = require('cluster');
+  return _cluster;
+}
 
 const errnoException = errors.errnoException;
 const exceptionWithHostPort = errors.exceptionWithHostPort;
@@ -200,8 +204,7 @@ function bufferSize(self, size, buffer) {
 
 // Query master process to get the server handle and utilize it.
 function bindServerHandle(self, options, errCb) {
-  if (!cluster)
-    cluster = require('cluster');
+  const cluster = lazyLoadCluster();
 
   const state = self[kStateSymbol];
   cluster._getServer(self, options, (err, handle) => {
@@ -262,8 +265,7 @@ Socket.prototype.bind = function(port_, address_ /* , callback */) {
     const exclusive = !!port.exclusive;
     const state = this[kStateSymbol];
 
-    if (!cluster)
-      cluster = require('cluster');
+    const cluster = lazyLoadCluster();
 
     if (cluster.isWorker && !exclusive) {
       bindServerHandle(this, {
@@ -325,8 +327,7 @@ Socket.prototype.bind = function(port_, address_ /* , callback */) {
       return;
     }
 
-    if (!cluster)
-      cluster = require('cluster');
+    const cluster = lazyLoadCluster();
 
     let flags = 0;
     if (state.reuseAddr)