test: replace callback with arrow functions

PR-URL: #24541
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

Author: sreepurnajasti

test/pummel/test-net-throttle.js

@@ -34,7 +34,7 @@ const body = 'C'.repeat(N);
 
 console.log(`start server on port ${common.PORT}`);
 
-constserver=net.createServer(function(connection){
+constserver=net.createServer((connection)=>{
 connection.write(body.slice(0,part_N));
 connection.write(body.slice(part_N,2*part_N));
 assert.strictEqual(connection.write(body.slice(2*part_N,N)),false);
@@ -44,11 +44,11 @@ const server = net.createServer(function(connection) {
 connection.end();
 });
 
-server.listen(common.PORT,function(){
+server.listen(common.PORT,()=>{
 letpaused=false;
 constclient=net.createConnection(common.PORT);
 client.setEncoding('ascii');
-client.on('data',function(d){
+client.on('data',(d)=>{
 chars_recved+=d.length;
 console.log(`got ${chars_recved}`);
 if(!paused){
@@ -57,7 +57,7 @@ server.listen(common.PORT, function() {
 paused=true;
 console.log('pause');
 constx=chars_recved;
-setTimeout(function(){
+setTimeout(()=>{
 assert.strictEqual(chars_recved,x);
 client.resume();
 console.log('resume');
@@ -66,14 +66,14 @@ server.listen(common.PORT, function() {
 }
 });
 
-client.on('end',function(){
+client.on('end',()=>{
 server.close();
 client.end();
 });
 });
 
 
-process.on('exit',function(){
+process.on('exit',()=>{
 assert.strictEqual(chars_recved,N);
 assert.strictEqual(npauses>2,true);
 });