test: Replacing anonymous closure function with arrow function

README.md

@@ -62,7 +62,7 @@ The open source license grants you the freedom to use Node.js. It does not
 guarantee commitments of other people's time. Please be respectful and manage
 your expectations.
 
-## Release Types 
+## Release Types
 
 * **Current**: Under active development. Code for the Current release is in the
   branch for its major version number (for example,

test/parallel/test-http-localaddress.js

@@ -28,26 +28,26 @@ if (!common.hasMultiLocalhost())
 const http = require('http');
 const assert = require('assert');
 
-const server = http.createServer(function(req, res) {
+const server = http.createServer((req, res) => {
   console.log(`Connect from: ${req.connection.remoteAddress}`);
   assert.strictEqual(req.connection.remoteAddress, '127.0.0.2');
 
-  req.on('end', function() {
+  req.on('end', () => {
     res.writeHead(200, { 'Content-Type': 'text/plain' });
     res.end(`You are from: ${req.connection.remoteAddress}`);
   });
   req.resume();
 });
 
-server.listen(0, '127.0.0.1', function() {
+server.listen(0, '127.0.0.1', () => {
   const options = { host: 'localhost',
                     port: this.address().port,
                     path: '/',
                     method: 'GET',
                     localAddress: '127.0.0.2' };
 
   const req = http.request(options, function(res) {
-    res.on('end', function() {
+    res.on('end', () => {
       server.close();
       process.exit();
     });

test/parallel/test-http-server-stale-close.js

@@ -34,10 +34,10 @@ if (process.env.NODE_TEST_FORK_PORT) {
   req.write('BAM');
   req.end();
 } else {
-  const server = http.createServer(function(req, res) {
+  const server = http.createServer((req, res) => {
     res.writeHead(200, { 'Content-Length': '42' });
     req.pipe(res);
-    req.on('close', function() {
+    req.on('close', () => {
       server.close();
       res.end();
     });