test: replace callback with arrow functions

PR-URL: #24434
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

test/parallel/test-https-close.js

@@ -13,16 +13,16 @@ const options = {
 
 const connections = {};
 
-const server = https.createServer(options, function(req, res) {
-  const interval = setInterval(function() {
+const server = https.createServer(options, (req, res) => {
+  const interval = setInterval(() => {
     res.write('data');
   }, 1000);
   interval.unref();
 });
 
-server.on('connection', function(connection) {
+server.on('connection', (connection) => {
   const key = `${connection.remoteAddress}:${connection.remotePort}`;
-  connection.on('close', function() {
+  connection.on('close', () => {
     delete connections[key];
   });
   connections[key] = connection;
@@ -37,16 +37,16 @@ function shutdown() {
   }
 }
 
-server.listen(0, function() {
+server.listen(0, () => {
   const requestOptions = {
     hostname: '127.0.0.1',
-    port: this.address().port,
+    port: server.address().port,
     path: '/',
     method: 'GET',
     rejectUnauthorized: false
   };
 
-  const req = https.request(requestOptions, function(res) {
+  const req = https.request(requestOptions, (res) => {
     res.on('data', () => {});
     setImmediate(shutdown);
   });