test: fix test-net-socket-constructor

So it doesn't fail when creating a socket whose `fd` is already
being watched. Test that functionality now inside a cluster
worker.
Refs: libuv/libuv#1851
Refs: libuv/libuv#1897
PR-URL: #21466
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: santigimeno

test/parallel/test-net-socket-constructor.js

@@ -2,6 +2,7 @@
 
 constcommon=require('../common');
 constassert=require('assert');
+constcluster=require('cluster');
 constnet=require('net');
 
 common.expectsError(()=>{
@@ -25,27 +26,40 @@ function test(sock, readable, writable) {
 assert.strictEqual(socket.writable,writable);
 }
 
-test(undefined,false,false);
+if(cluster.isMaster){
+test(undefined,false,false);
 
-constserver=net.createServer(common.mustCall((socket)=>{
-test(socket,true,true);
-test({handle: socket._handle},false,false);
-test({handle: socket._handle,readable: true,writable: true},true,true);
-if(socket._handle.fd>=0){
-test(socket._handle.fd,false,false);
-test({fd: socket._handle.fd},false,false);
-test({fd: socket._handle.fd,readable: true,writable: true},true,true);
-}
+constserver=net.createServer(common.mustCall((socket)=>{
+socket.unref();
+test(socket,true,true);
+test({handle: socket._handle},false,false);
+test({handle: socket._handle,readable: true,writable: true},
+true,true);
+server.close();
+}));
 
-server.close();
-}));
+server.listen(common.mustCall(()=>{
+const{ port }=server.address();
+constsocket=net.connect(port,common.mustCall(()=>{
+test(socket,true,true);
+socket.end();
+}));
 
-server.listen(common.mustCall(()=>{
-const{ port }=server.address();
-constsocket=net.connect(port,common.mustCall(()=>{
-test(socket,true,true);
-socket.end();
+test(socket,false,true);
 }));
 
-test(socket,false,true);
-}));
+cluster.setupMaster({
+stdio: ['pipe','pipe','pipe','ipc','pipe','pipe','pipe']
+});
+
+constworker=cluster.fork();
+worker.on('exit',common.mustCall((code,signal)=>{
+assert.strictEqual(code,0);
+assert.strictEqual(signal,null);
+}));
+}else{
+test(4,false,false);
+test({fd: 5},false,false);
+test({fd: 6,readable: true,writable: true},true,true);
+process.disconnect();
+}