test: fix flaky test-net-socket-local-address

Prior to this commit, the test was flaky because it was
executing the majority of its logic in a function called from
the client and multiple events on the server. This commit
simplifies the test by separating the server's connection and
listening events, and isolating the client logic.
Refs: #4476
Refs: #4644
PR-URL: #4650
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

Author: cjihrig

test/parallel/test-net-socket-local-address.js

@@ -12,35 +12,29 @@ if (common.inFreeBSDJail) {
 varconns=0;
 varclientLocalPorts=[];
 varserverRemotePorts=[];
-
-constserver=net.createServer(function(socket){
+constclient=newnet.Socket();
+constserver=net.createServer(socket=>{
 serverRemotePorts.push(socket.remotePort);
-testConnect();
+socket.end();
 });
 
-constclient=newnet.Socket();
-
-server.on('close',common.mustCall(function(){
+server.on('close',common.mustCall(()=>{
 assert.deepEqual(clientLocalPorts,serverRemotePorts,
 'client and server should agree on the ports used');
-assert.equal(2,conns);
+assert.strictEqual(2,conns);
 }));
 
-server.listen(common.PORT,common.localhostIPv4,testConnect);
+server.listen(common.PORT,common.localhostIPv4,connect);
 
-functiontestConnect(){
-if(conns>serverRemotePorts.length||conns>clientLocalPorts.length){
-// We're waiting for a callback to fire.
+functionconnect(){
+if(conns===2){
+server.close();
 return;
 }
 
-if(conns===2){
-returnserver.close();
-}
-client.connect(common.PORT,common.localhostIPv4,function(){
-clientLocalPorts.push(this.localPort);
-this.once('close',testConnect);
-this.destroy();
-});
 conns++;
+client.once('close',connect);
+client.connect(common.PORT,common.localhostIPv4,()=>{
+clientLocalPorts.push(client.localPort);
+});
 }