test: use random ports where possible

This helps to prevent issues where a failed test can keep a bound
socket open long enough to cause other tests to fail with EADDRINUSE
because the same port number is used.

PR-URL: https://github.com/nodejs/node/pull/7045
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Rod Vagg <rod@vagg.org>

test/parallel/test-async-wrap-check-providers.js

@@ -81,12 +81,12 @@ net.createServer(function(c) {
 net.createServer(function(c) {
   c.end();
   this.close(checkTLS);
-}).listen(common.PORT, function() {
-  net.connect(common.PORT, noop);
+}).listen(0, function() {
+  net.connect(this.address().port, noop);
 });
 
-dgram.createSocket('udp4').bind(common.PORT, function() {
-  this.send(Buffer.allocUnsafe(2), 0, 2, common.PORT, '::', () => {
+dgram.createSocket('udp4').bind(0, function() {
+  this.send(Buffer.allocUnsafe(2), 0, 2, this.address().port, '::', () => {
     this.close();
   });
 });
@@ -100,8 +100,9 @@ function checkTLS() {
     cert: fs.readFileSync(common.fixturesDir + '/keys/ec-cert.pem')
   };
   const server = tls.createServer(options, noop)
-    .listen(common.PORT, function() {
-      tls.connect(common.PORT, { rejectUnauthorized: false }, function() {
+    .listen(0, function() {
+      const connectOpts = { rejectUnauthorized: false };
+      tls.connect(this.address().port, connectOpts, function() {
         this.destroy();
         server.close();
       });

test/parallel/test-async-wrap-disabled-propagate-parent.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const net = require('net');
 const async_wrap = process.binding('async_wrap');
@@ -40,8 +40,8 @@ const server = net.createServer(function(c) {
     c.end();
     this.close();
   });
-}).listen(common.PORT, function() {
-  net.connect(common.PORT, noop);
+}).listen(0, function() {
+  net.connect(this.address().port, noop);
 });
 
 async_wrap.disable();

test/parallel/test-async-wrap-propagate-parent.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const net = require('net');
 const async_wrap = process.binding('async_wrap');
@@ -40,8 +40,8 @@ const server = net.createServer(function(c) {
     c.end();
     this.close();
   });
-}).listen(common.PORT, function() {
-  net.connect(common.PORT, noop);
+}).listen(0, function() {
+  net.connect(this.address().port, noop);
 });
 
 

test/parallel/test-beforeexit-event.js

@@ -1,7 +1,7 @@
 'use strict';
+require('../common');
 var assert = require('assert');
 var net = require('net');
-var common = require('../common');
 var revivals = 0;
 var deaths = 0;
 
@@ -29,7 +29,7 @@ function tryTimer() {
 function tryListen() {
   console.log('create a server');
   net.createServer()
-    .listen(common.PORT)
+    .listen(0)
     .on('listening', function() {
       revivals++;
       this.close();

test/parallel/test-child-process-disconnect.js

@@ -38,10 +38,10 @@ if (process.argv[2] === 'child') {
 
   // when the server is ready tell parent
   server.on('listening', function() {
-    process.send('ready');
+    process.send({ msg: 'ready', port: server.address().port });
   });
 
-  server.listen(common.PORT);
+  server.listen(0);
 
 } else {
   // testcase
@@ -65,11 +65,11 @@ if (process.argv[2] === 'child') {
   });
 
   // when child is listening
-  child.on('message', function(msg) {
-    if (msg === 'ready') {
+  child.on('message', function(obj) {
+    if (obj && obj.msg === 'ready') {
 
       // connect to child using TCP to know if disconnect was emitted
-      var socket = net.connect(common.PORT);
+      var socket = net.connect(obj.port);
 
       socket.on('data', function(data) {
         data = data.toString();

test/parallel/test-child-process-fork-dgram.js

@@ -72,7 +72,7 @@ if (process.argv[2] === 'child') {
         msg,
         0,
         msg.length,
-        common.PORT,
+        server.address().port,
         '127.0.0.1',
         function(err) {
           if (err) throw err;
@@ -98,7 +98,7 @@ if (process.argv[2] === 'child') {
     client.close();
   };
 
-  server.bind(common.PORT, '127.0.0.1');
+  server.bind(0, '127.0.0.1');
 
   process.once('exit', function() {
     assert(parentGotMessage);

test/parallel/test-child-process-fork-net.js

@@ -1,6 +1,6 @@
 'use strict';
-const assert = require('assert');
 require('../common');
+const assert = require('assert');
 const fork = require('child_process').fork;
 const net = require('net');
 

test/parallel/test-child-process-fork-net2.js

@@ -99,7 +99,7 @@ if (process.argv[2] === 'child') {
 
     var j = count, client;
     while (j--) {
-      client = net.connect(common.PORT, '127.0.0.1');
+      client = net.connect(this.address().port, '127.0.0.1');
       client.on('error', function() {
         // This can happen if we kill the child too early.
         // The client should still get a close event afterwards.
@@ -125,7 +125,7 @@ if (process.argv[2] === 'child') {
     child3.kill();
   }));
 
-  server.listen(common.PORT, '127.0.0.1');
+  server.listen(0, '127.0.0.1');
 
   var closeServer = function() {
     server.close();

test/parallel/test-child-process-fork-regr-gh-2847.js

@@ -25,11 +25,11 @@ var server = net.createServer(function(s) {
   setTimeout(function() {
     s.destroy();
   }, 100);
-}).listen(common.PORT, function() {
+}).listen(0, function() {
   var worker = cluster.fork();
 
   function send(callback) {
-    var s = net.connect(common.PORT, function() {
+    var s = net.connect(server.address().port, function() {
       worker.send({}, s, callback);
     });
 

test/parallel/test-child-process-recv-handle.js

@@ -24,7 +24,7 @@ function master() {
   });
   proc.stdout.on('data', function(data) {
     assert.equal(data, 'ok\r\n');
-    net.createServer(common.fail).listen(common.PORT, function() {
+    net.createServer(common.fail).listen(0, function() {
       handle = this._handle;
       proc.send('one');
       proc.send('two', handle);

test/parallel/test-child-process-send-keep-open.js

@@ -37,8 +37,8 @@ if (process.argv[2] !== 'child') {
     }));
   });
 
-  server.listen(common.PORT, () => {
-    const socket = net.connect(common.PORT, common.localhostIPv4);
+  server.listen(0, () => {
+    const socket = net.connect(server.address().port, common.localhostIPv4);
     socket.setEncoding('utf8');
     socket.on('data', (data) => result += data);
   });

test/parallel/test-child-process-send-returns-boolean.js

@@ -20,7 +20,7 @@ s.on('exit', function() {
   handle.close();
 });
 
-net.createServer(common.fail).listen(common.PORT, function() {
+net.createServer(common.fail).listen(0, function() {
   handle = this._handle;
   assert.strictEqual(s.send('one', handle), true);
   assert.strictEqual(s.send('two', handle), true);

test/parallel/test-crypto-verify-failure.js

@@ -36,9 +36,9 @@ function verify() {
     .verify(certPem, 'asdfasdfas', 'base64');
 }
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   tls.connect({
-    port: common.PORT,
+    port: this.address().port,
     rejectUnauthorized: false
   }, function() {
     verify();

test/parallel/test-dgram-address.js

@@ -10,7 +10,9 @@ var family_ipv4 = 'IPv4';
 socket_ipv4.on('listening', function() {
   var address_ipv4 = socket_ipv4.address();
   assert.strictEqual(address_ipv4.address, common.localhostIPv4);
-  assert.strictEqual(address_ipv4.port, common.PORT);
+  assert.strictEqual(typeof address_ipv4.port, 'number');
+  assert.ok(isFinite(address_ipv4.port));
+  assert.ok(address_ipv4.port > 0);
   assert.strictEqual(address_ipv4.family, family_ipv4);
   socket_ipv4.close();
 });
@@ -20,7 +22,7 @@ socket_ipv4.on('error', function(e) {
   socket_ipv4.close();
 });
 
-socket_ipv4.bind(common.PORT, common.localhostIPv4);
+socket_ipv4.bind(0, common.localhostIPv4);
 
 // IPv6 Test
 var localhost_ipv6 = '::1';
@@ -30,7 +32,9 @@ var family_ipv6 = 'IPv6';
 socket_ipv6.on('listening', function() {
   var address_ipv6 = socket_ipv6.address();
   assert.strictEqual(address_ipv6.address, localhost_ipv6);
-  assert.strictEqual(address_ipv6.port, common.PORT);
+  assert.strictEqual(typeof address_ipv6.port, 'number');
+  assert.ok(isFinite(address_ipv6.port));
+  assert.ok(address_ipv6.port > 0);
   assert.strictEqual(address_ipv6.family, family_ipv6);
   socket_ipv6.close();
 });
@@ -40,4 +44,4 @@ socket_ipv6.on('error', function(e) {
   socket_ipv6.close();
 });
 
-socket_ipv6.bind(common.PORT, localhost_ipv6);
+socket_ipv6.bind(0, localhost_ipv6);

test/parallel/test-dgram-bind-default-address.js

@@ -9,8 +9,10 @@ if (common.inFreeBSDJail) {
   return;
 }
 
-dgram.createSocket('udp4').bind(common.PORT + 0, common.mustCall(function() {
-  assert.equal(this.address().port, common.PORT + 0);
+dgram.createSocket('udp4').bind(0, common.mustCall(function() {
+  assert.strictEqual(typeof this.address().port, 'number');
+  assert.ok(isFinite(this.address().port));
+  assert.ok(this.address().port > 0);
   assert.equal(this.address().address, '0.0.0.0');
   this.close();
 }));
@@ -20,8 +22,10 @@ if (!common.hasIPv6) {
   return;
 }
 
-dgram.createSocket('udp6').bind(common.PORT + 1, common.mustCall(function() {
-  assert.equal(this.address().port, common.PORT + 1);
+dgram.createSocket('udp6').bind(0, common.mustCall(function() {
+  assert.strictEqual(typeof this.address().port, 'number');
+  assert.ok(isFinite(this.address().port));
+  assert.ok(this.address().port > 0);
   var address = this.address().address;
   if (address === '::ffff:0.0.0.0')
     address = '::';

test/parallel/test-dgram-empty-packet.js

@@ -13,27 +13,28 @@ if (process.platform === 'darwin') {
 
 client = dgram.createSocket('udp4');
 
-client.bind(common.PORT);
-
-function callback() {
-  callbacks++;
-  if (callbacks == 2) {
-    clearTimeout(timer);
-    client.close();
-  } else if (callbacks > 2) {
-    throw new Error('the callbacks should be called only two times');
+client.bind(0, function() {
+  function callback() {
+    callbacks++;
+    if (callbacks == 2) {
+      clearTimeout(timer);
+      client.close();
+    } else if (callbacks > 2) {
+      throw new Error('the callbacks should be called only two times');
+    }
   }
-}
 
-client.on('message', function(buffer, bytes) {
-  callback();
-});
-
-client.send(
-  Buffer.allocUnsafe(1), 0, 0, common.PORT, '127.0.0.1', (err, len) => {
+  client.on('message', function(buffer, bytes) {
     callback();
   });
 
-timer = setTimeout(function() {
-  throw new Error('Timeout');
-}, 200);
+  const port = this.address().port;
+  client.send(
+    Buffer.allocUnsafe(1), 0, 0, port, '127.0.0.1', (err, len) => {
+      callback();
+    });
+
+  timer = setTimeout(function() {
+    throw new Error('Timeout');
+  }, 200);
+});

test/parallel/test-dgram-error-message-address.js

@@ -9,14 +9,14 @@ var socket_ipv4 = dgram.createSocket('udp4');
 socket_ipv4.on('listening', common.fail);
 
 socket_ipv4.on('error', common.mustCall(function(e) {
-  assert.equal(e.message, 'bind EADDRNOTAVAIL 1.1.1.1:' + common.PORT);
+  assert.strictEqual(e.port, undefined);
+  assert.equal(e.message, 'bind EADDRNOTAVAIL 1.1.1.1');
   assert.equal(e.address, '1.1.1.1');
-  assert.equal(e.port, common.PORT);
   assert.equal(e.code, 'EADDRNOTAVAIL');
   socket_ipv4.close();
 }));
 
-socket_ipv4.bind(common.PORT, '1.1.1.1');
+socket_ipv4.bind(0, '1.1.1.1');
 
 // IPv6 Test
 var socket_ipv6 = dgram.createSocket('udp6');
@@ -27,10 +27,10 @@ socket_ipv6.on('error', common.mustCall(function(e) {
   // EAFNOSUPPORT or EPROTONOSUPPORT means IPv6 is disabled on this system.
   var allowed = ['EADDRNOTAVAIL', 'EAFNOSUPPORT', 'EPROTONOSUPPORT'];
   assert.notEqual(allowed.indexOf(e.code), -1);
-  assert.equal(e.message, 'bind ' + e.code + ' 111::1:' + common.PORT);
+  assert.strictEqual(e.port, undefined);
+  assert.equal(e.message, 'bind ' + e.code + ' 111::1');
   assert.equal(e.address, '111::1');
-  assert.equal(e.port, common.PORT);
   socket_ipv6.close();
 }));
 
-socket_ipv6.bind(common.PORT, '111::1');
+socket_ipv6.bind(0, '111::1');

test/parallel/test-dgram-implicit-bind.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var dgram = require('dgram');
 
@@ -22,8 +22,9 @@ target.on('message', function(buf) {
 
 target.on('listening', function() {
   // Second .send() call should not throw a bind error.
-  source.send(Buffer.from('abc'), 0, 3, common.PORT, '127.0.0.1');
-  source.send(Buffer.from('def'), 0, 3, common.PORT, '127.0.0.1');
+  const port = this.address().port;
+  source.send(Buffer.from('abc'), 0, 3, port, '127.0.0.1');
+  source.send(Buffer.from('def'), 0, 3, port, '127.0.0.1');
 });
 
-target.bind(common.PORT);
+target.bind(0);

test/parallel/test-dgram-multicast-setTTL.js

@@ -1,11 +1,11 @@
 'use strict';
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const dgram = require('dgram');
 const socket = dgram.createSocket('udp4');
 let thrown = false;
 
-socket.bind(common.PORT);
+socket.bind(0);
 socket.on('listening', function() {
   socket.setMulticastTTL(16);
 

test/parallel/test-dgram-send-callback-multi-buffer.js

@@ -19,7 +19,8 @@ const buf1 = Buffer.alloc(256, 'x');
 const buf2 = Buffer.alloc(256, 'y');
 
 client.on('listening', function() {
-  client.send([buf1, buf2], common.PORT, common.localhostIPv4, messageSent);
+  const port = this.address().port;
+  client.send([buf1, buf2], port, common.localhostIPv4, messageSent);
 });
 
 client.on('message', common.mustCall(function onMessage(buf, info) {
@@ -28,4 +29,4 @@ client.on('message', common.mustCall(function onMessage(buf, info) {
   client.close();
 }));
 
-client.bind(common.PORT);
+client.bind(0);

test/parallel/test-dgram-send-callback-recursive.js

@@ -9,17 +9,19 @@ let received = 0;
 let sent = 0;
 const limit = 10;
 let async = false;
+let port;
 
 function onsend() {
   if (sent++ < limit) {
-    client.send(
-      chunk, 0, chunk.length, common.PORT, common.localhostIPv4, onsend);
+    client.send(chunk, 0, chunk.length, port, common.localhostIPv4, onsend);
   } else {
     assert.strictEqual(async, true, 'Send should be asynchronous.');
   }
 }
 
 client.on('listening', function() {
+  port = this.address().port;
+
   setImmediate(function() {
     async = true;
   });
@@ -38,4 +40,4 @@ client.on('close', common.mustCall(function() {
   assert.equal(received, limit);
 }));
 
-client.bind(common.PORT);
+client.bind(0);

test/parallel/test-dgram-send-default-host.js

@@ -14,10 +14,11 @@ const toSend = [Buffer.alloc(256, 'x'),
 const received = [];
 
 client.on('listening', common.mustCall(() => {
-  client.send(toSend[0], 0, toSend[0].length, common.PORT);
-  client.send(toSend[1], common.PORT);
-  client.send([toSend[2]], common.PORT);
-  client.send(toSend[3], 0, toSend[3].length, common.PORT);
+  const port = client.address().port;
+  client.send(toSend[0], 0, toSend[0].length, port);
+  client.send(toSend[1], port);
+  client.send([toSend[2]], port);
+  client.send(toSend[3], 0, toSend[3].length, port);
 }));
 
 client.on('message', common.mustCall((buf, info) => {
@@ -33,4 +34,4 @@ client.on('message', common.mustCall((buf, info) => {
   }
 }, toSend.length));
 
-client.bind(common.PORT);
+client.bind(0);

test/parallel/test-dgram-send-empty-array.js

@@ -23,7 +23,7 @@ client.on('message', common.mustCall(function onMessage(buf, info) {
 }));
 
 client.on('listening', function() {
-  client.send([], common.PORT, common.localhostIPv4);
+  client.send([], this.address().port, common.localhostIPv4);
 });
 
-client.bind(common.PORT);
+client.bind(0);

test/parallel/test-dgram-send-empty-buffer.js

@@ -9,16 +9,18 @@ if (process.platform === 'darwin') {
 
 const client = dgram.createSocket('udp4');
 
-client.bind(common.PORT);
+client.bind(0, function() {
+  const port = this.address().port;
 
-client.on('message', common.mustCall(function onMessage(buffer, bytes) {
-  clearTimeout(timer);
-  client.close();
-}));
+  client.on('message', common.mustCall(function onMessage(buffer, bytes) {
+    clearTimeout(timer);
+    client.close();
+  }));
 
-const buf = Buffer.alloc(0);
-client.send(buf, 0, 0, common.PORT, '127.0.0.1', function(err, len) { });
+  const buf = Buffer.alloc(0);
+  client.send(buf, 0, 0, port, '127.0.0.1', function(err, len) { });
 
-const timer = setTimeout(function() {
-  throw new Error('Timeout');
-}, common.platformTimeout(200));
+  const timer = setTimeout(function() {
+    throw new Error('Timeout');
+  }, common.platformTimeout(200));
+});

test/parallel/test-dgram-send-multi-buffer-copy.js

@@ -20,7 +20,7 @@ const buf2 = Buffer.alloc(256, 'y');
 
 client.on('listening', function() {
   const toSend = [buf1, buf2];
-  client.send(toSend, common.PORT, common.localhostIPv4, onMessage);
+  client.send(toSend, this.address().port, common.localhostIPv4, onMessage);
   toSend.splice(0, 2);
 });
 
@@ -30,4 +30,4 @@ client.on('message', common.mustCall(function onMessage(buf, info) {
   client.close();
 }));
 
-client.bind(common.PORT);
+client.bind(0);

test/parallel/test-dgram-setBroadcast.js

@@ -26,14 +26,14 @@ runTest((socket) => { socket.setBroadcast(true); }, /EBADF/);
 
 // Should not throw if broadcast set to false after binding.
 runTest((socket) => {
-  socket.bind(common.PORT, common.localhostIPv4, () => {
+  socket.bind(0, common.localhostIPv4, () => {
     socket.setBroadcast(false);
   });
 });
 
 // Should not throw if broadcast set to true after binding.
 runTest((socket) => {
-  socket.bind(common.PORT, common.localhostIPv4, () => {
+  socket.bind(0, common.localhostIPv4, () => {
     socket.setBroadcast(true);
   });
 });

test/parallel/test-dgram-setTTL.js

@@ -1,10 +1,10 @@
 'use strict';
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const dgram = require('dgram');
 const socket = dgram.createSocket('udp4');
 
-socket.bind(common.PORT);
+socket.bind(0);
 socket.on('listening', function() {
   var result = socket.setTTL(16);
   assert.strictEqual(result, 16);

test/parallel/test-dgram-udp4.js

@@ -2,7 +2,6 @@
 const common = require('../common');
 const assert = require('assert');
 const dgram = require('dgram');
-const server_port = common.PORT;
 const message_to_send = 'A message to send';
 
 const server = dgram.createSocket('udp4');
@@ -13,9 +12,10 @@ server.on('message', common.mustCall((msg, rinfo) => {
 }));
 server.on('listening', common.mustCall(() => {
   const client = dgram.createSocket('udp4');
+  const port = server.address().port;
   client.on('message', common.mustCall((msg, rinfo) => {
     assert.strictEqual(rinfo.address, common.localhostIPv4);
-    assert.strictEqual(rinfo.port, server_port);
+    assert.strictEqual(rinfo.port, port);
     assert.strictEqual(msg.toString(), message_to_send.toString());
     client.close();
     server.close();
@@ -23,10 +23,9 @@ server.on('listening', common.mustCall(() => {
   client.send(message_to_send,
               0,
               message_to_send.length,
-              server_port,
+              port,
               'localhost');
   client.on('close', common.mustCall(() => {}));
 }));
 server.on('close', common.mustCall(() => {}));
-server.bind(server_port);
-
+server.bind(0);

test/parallel/test-dgram-udp6-send-default-host.js

@@ -19,10 +19,11 @@ const toSend = [Buffer.alloc(256, 'x'),
 const received = [];
 
 client.on('listening', common.mustCall(() => {
-  client.send(toSend[0], 0, toSend[0].length, common.PORT);
-  client.send(toSend[1], common.PORT);
-  client.send([toSend[2]], common.PORT);
-  client.send(toSend[3], 0, toSend[3].length, common.PORT);
+  const port = client.address().port;
+  client.send(toSend[0], 0, toSend[0].length, port);
+  client.send(toSend[1], port);
+  client.send([toSend[2]], port);
+  client.send(toSend[3], 0, toSend[3].length, port);
 }));
 
 client.on('message', common.mustCall((buf, info) => {
@@ -38,4 +39,4 @@ client.on('message', common.mustCall((buf, info) => {
   }
 }, toSend.length));
 
-client.bind(common.PORT);
+client.bind(0);

test/parallel/test-domain-abort-on-uncaught.js

@@ -109,8 +109,8 @@ const tests = [
       const server = net.createServer(function(conn) {
         conn.pipe(conn);
       });
-      server.listen(common.PORT, common.localhostIPv4, function() {
-        const conn = net.connect(common.PORT, common.localhostIPv4);
+      server.listen(0, common.localhostIPv4, function() {
+        const conn = net.connect(this.address().port, common.localhostIPv4);
         conn.once('data', function() {
           throw new Error('ok');
         });

test/parallel/test-domain-http-server.js

@@ -1,8 +1,8 @@
 'use strict';
+require('../common');
 var domain = require('domain');
 var http = require('http');
 var assert = require('assert');
-var common = require('../common');
 
 var objects = { foo: 'bar', baz: {}, num: 42, arr: [1, 2, 3] };
 objects.baz.asdf = objects;
@@ -37,10 +37,11 @@ var server = http.createServer(function(req, res) {
   });
 });
 
-server.listen(common.PORT, next);
+server.listen(0, next);
 
 function next() {
-  console.log('listening on localhost:%d', common.PORT);
+  const port = this.address().port;
+  console.log('listening on localhost:%d', port);
 
   var requests = 0;
   var responses = 0;
@@ -61,7 +62,7 @@ function next() {
       req.socket.destroy();
     });
 
-    var req = http.get({ host: 'localhost', port: common.PORT, path: p });
+    var req = http.get({ host: 'localhost', port: port, path: p });
     dom.add(req);
     req.on('response', function(res) {
       responses++;

test/parallel/test-domain-multi.js

@@ -1,7 +1,7 @@
 'use strict';
 // Tests of multiple domains happening at once.
 
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var domain = require('domain');
 
@@ -49,24 +49,24 @@ var server = http.createServer(function(req, res) {
     throw new Error('this kills domain B, not A');
   }));
 
-}).listen(common.PORT);
+}).listen(0, function() {
+  var c = domain.create();
+  var req = http.get({ host: 'localhost', port: this.address().port });
 
-var c = domain.create();
-var req = http.get({ host: 'localhost', port: common.PORT });
+  // add the request to the C domain
+  c.add(req);
 
-// add the request to the C domain
-c.add(req);
+  req.on('response', function(res) {
+    console.error('got response');
+    // add the response object to the C domain
+    c.add(res);
+    res.pipe(process.stdout);
+  });
 
-req.on('response', function(res) {
-  console.error('got response');
-  // add the response object to the C domain
-  c.add(res);
-  res.pipe(process.stdout);
-});
-
-c.on('error', function(er) {
-  caughtC = true;
-  console.error('Error on c', er.message);
+  c.on('error', function(er) {
+    caughtC = true;
+    console.error('Error on c', er.message);
+  });
 });
 
 process.on('exit', function() {

test/parallel/test-handle-wrap-isrefed.js

@@ -72,7 +72,7 @@ function makeAssert(message) {
 {
   const assert = makeAssert('hasRef() not working on tcp_wrap');
   const net = require('net');
-  const server = net.createServer(() => {}).listen(common.PORT);
+  const server = net.createServer(() => {}).listen(0);
   assert(Object.getPrototypeOf(server._handle).hasOwnProperty('hasRef'), true);
   assert(server._handle.hasRef(), true);
   assert(server._unref, false);

test/parallel/test-http-1.0-keep-alive.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var http = require('http');
 var net = require('net');
 
@@ -84,14 +84,17 @@ check([{
 
 function check(tests) {
   var test = tests[0];
-  if (test) http.createServer(server).listen(common.PORT, '127.0.0.1', client);
+  var server;
+  if (test) {
+    server = http.createServer(serverHandler).listen(0, '127.0.0.1', client);
+  }
   var current = 0;
 
   function next() {
     check(tests.slice(1));
   }
 
-  function server(req, res) {
+  function serverHandler(req, res) {
     if (current + 1 === test.responses.length) this.close();
     var ctx = test.responses[current];
     console.error('<  SERVER SENDING RESPONSE', ctx);
@@ -102,7 +105,8 @@ function check(tests) {
 
   function client() {
     if (current === test.requests.length) return next();
-    var conn = net.createConnection(common.PORT, '127.0.0.1', connected);
+    const port = server.address().port;
+    var conn = net.createConnection(port, '127.0.0.1', connected);
 
     function connected() {
       var ctx = test.requests[current];

test/parallel/test-http-1.0.js

@@ -6,18 +6,15 @@ var http = require('http');
 
 var body = 'hello world\n';
 
-var common_port = common.PORT;
-
 function test(handler, request_generator, response_validator) {
-  var port = common_port++;
   var server = http.createServer(handler);
 
   var client_got_eof = false;
   var server_response = '';
 
-  server.listen(port);
+  server.listen(0);
   server.on('listening', function() {
-    var c = net.createConnection(port);
+    var c = net.createConnection(this.address().port);
 
     c.setEncoding('utf8');
 

test/parallel/test-http-abort-before-end.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var http = require('http');
 var assert = require('assert');
 
@@ -7,8 +7,12 @@ var server = http.createServer(function(req, res) {
   assert(false); // should not be called
 });
 
-server.listen(common.PORT, function() {
-  var req = http.request({method: 'GET', host: '127.0.0.1', port: common.PORT});
+server.listen(0, function() {
+  var req = http.request({
+    method: 'GET',
+    host: '127.0.0.1',
+    port: this.address().port
+  });
 
   req.on('error', function(ex) {
     // https://github.com/joyent/node/issues/1399#issuecomment-2597359

test/parallel/test-http-abort-client.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var http = require('http');
 var assert = require('assert');
 
@@ -13,11 +13,10 @@ var server = http.Server(function(req, res) {
 
 var responseClose = false;
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   http.get({
-    port: common.PORT,
+    port: this.address().port,
     headers: { connection: 'keep-alive' }
-
   }, function(res) {
     server.close();
 

test/parallel/test-http-abort-queued.js

@@ -1,6 +1,6 @@
 'use strict';
+require('../common');
 const assert = require('assert');
-const common = require('../common');
 const http = require('http');
 
 var complete;
@@ -19,7 +19,7 @@ var server = http.createServer(function(req, res) {
 });
 
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   console.log('listen', server.address().port);
 
   var agent = new http.Agent({maxSockets: 1});

test/parallel/test-http-after-connect.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -26,9 +26,9 @@ server.on('connect', function(req, socket, firstBodyChunk) {
     socket.end();
   });
 });
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'CONNECT',
     path: 'google.com:80'
   });
@@ -46,7 +46,7 @@ server.listen(common.PORT, function() {
 
 function doRequest(i) {
   http.get({
-    port: common.PORT,
+    port: server.address().port,
     path: '/request' + i
   }, function(res) {
     console.error('Client got GET response');

test/parallel/test-http-agent-destroyed-socket.js

@@ -1,86 +1,86 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
 var server = http.createServer(function(req, res) {
   res.writeHead(200, {'Content-Type': 'text/plain'});
   res.end('Hello World\n');
-}).listen(common.PORT);
+}).listen(0, function() {
+  var agent = new http.Agent({maxSockets: 1});
 
-var agent = new http.Agent({maxSockets: 1});
-
-agent.on('free', function(socket, host, port) {
-  console.log('freeing socket. destroyed? ', socket.destroyed);
-});
-
-var requestOptions = {
-  agent: agent,
-  host: 'localhost',
-  port: common.PORT,
-  path: '/'
-};
-
-var request1 = http.get(requestOptions, function(response) {
-  // assert request2 is queued in the agent
-  var key = agent.getName(requestOptions);
-  assert(agent.requests[key].length === 1);
-  console.log('got response1');
-  request1.socket.on('close', function() {
-    console.log('request1 socket closed');
+  agent.on('free', function(socket, host, port) {
+    console.log('freeing socket. destroyed? ', socket.destroyed);
   });
-  response.pipe(process.stdout);
-  response.on('end', function() {
-    console.log('response1 done');
-    /////////////////////////////////
-    //
-    // THE IMPORTANT PART
-    //
-    // It is possible for the socket to get destroyed and other work
-    // to run before the 'close' event fires because it happens on
-    // nextTick. This example is contrived because it destroys the
-    // socket manually at just the right time, but at Voxer we have
-    // seen cases where the socket is destroyed by non-user code
-    // then handed out again by an agent *before* the 'close' event
-    // is triggered.
-    request1.socket.destroy();
 
-    response.once('close', function() {
-      // assert request2 was removed from the queue
-      assert(!agent.requests[key]);
-      console.log("waiting for request2.onSocket's nextTick");
-      process.nextTick(function() {
-        // assert that the same socket was not assigned to request2,
-        // since it was destroyed.
-        assert(request1.socket !== request2.socket);
-        assert(!request2.socket.destroyed, 'the socket is destroyed');
+  var requestOptions = {
+    agent: agent,
+    host: 'localhost',
+    port: this.address().port,
+    path: '/'
+  };
+
+  var request1 = http.get(requestOptions, function(response) {
+    // assert request2 is queued in the agent
+    var key = agent.getName(requestOptions);
+    assert(agent.requests[key].length === 1);
+    console.log('got response1');
+    request1.socket.on('close', function() {
+      console.log('request1 socket closed');
+    });
+    response.pipe(process.stdout);
+    response.on('end', function() {
+      console.log('response1 done');
+      /////////////////////////////////
+      //
+      // THE IMPORTANT PART
+      //
+      // It is possible for the socket to get destroyed and other work
+      // to run before the 'close' event fires because it happens on
+      // nextTick. This example is contrived because it destroys the
+      // socket manually at just the right time, but at Voxer we have
+      // seen cases where the socket is destroyed by non-user code
+      // then handed out again by an agent *before* the 'close' event
+      // is triggered.
+      request1.socket.destroy();
+
+      response.once('close', function() {
+        // assert request2 was removed from the queue
+        assert(!agent.requests[key]);
+        console.log("waiting for request2.onSocket's nextTick");
+        process.nextTick(function() {
+          // assert that the same socket was not assigned to request2,
+          // since it was destroyed.
+          assert(request1.socket !== request2.socket);
+          assert(!request2.socket.destroyed, 'the socket is destroyed');
+        });
       });
     });
   });
-});
 
-var request2 = http.get(requestOptions, function(response) {
-  assert(!request2.socket.destroyed);
-  assert(request1.socket.destroyed);
-  // assert not reusing the same socket, since it was destroyed.
-  assert(request1.socket !== request2.socket);
-  console.log('got response2');
-  var gotClose = false;
-  var gotResponseEnd = false;
-  request2.socket.on('close', function() {
-    console.log('request2 socket closed');
-    gotClose = true;
-    done();
-  });
-  response.pipe(process.stdout);
-  response.on('end', function() {
-    console.log('response2 done');
-    gotResponseEnd = true;
-    done();
-  });
+  var request2 = http.get(requestOptions, function(response) {
+    assert(!request2.socket.destroyed);
+    assert(request1.socket.destroyed);
+    // assert not reusing the same socket, since it was destroyed.
+    assert(request1.socket !== request2.socket);
+    console.log('got response2');
+    var gotClose = false;
+    var gotResponseEnd = false;
+    request2.socket.on('close', function() {
+      console.log('request2 socket closed');
+      gotClose = true;
+      done();
+    });
+    response.pipe(process.stdout);
+    response.on('end', function() {
+      console.log('response2 done');
+      gotResponseEnd = true;
+      done();
+    });
 
-  function done() {
-    if (gotResponseEnd && gotClose)
-      server.close();
-  }
+    function done() {
+      if (gotResponseEnd && gotClose)
+        server.close();
+    }
+  });
 });

test/parallel/test-http-agent-error-on-idle.js

@@ -1,31 +1,27 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 var Agent = http.Agent;
 
-var agent = new Agent({
-  keepAlive: true,
-});
-
-var requestParams = {
-  host: 'localhost',
-  port: common.PORT,
-  agent: agent,
-  path: '/'
-};
-
-var socketKey = agent.getName(requestParams);
-
-function get(callback) {
-  return http.get(requestParams, callback);
-}
-
 var server = http.createServer(function(req, res) {
   res.end('hello world');
 });
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
+  var agent = new Agent({
+    keepAlive: true,
+  });
+
+  var requestParams = {
+    host: 'localhost',
+    port: this.address().port,
+    agent: agent,
+    path: '/'
+  };
+
+  var socketKey = agent.getName(requestParams);
+
   get(function(res) {
     assert.equal(res.statusCode, 200);
     res.resume();
@@ -43,13 +39,17 @@ server.listen(common.PORT, function() {
       });
     });
   });
+
+  function get(callback) {
+    return http.get(requestParams, callback);
+  }
+
+  function done() {
+    assert.equal(Object.keys(agent.freeSockets).length, 0,
+                 'expect the freeSockets pool to be empty');
+
+    agent.destroy();
+    server.close();
+    process.exit(0);
+  }
 });
-
-function done() {
-  assert.equal(Object.keys(agent.freeSockets).length, 0,
-               'expect the freeSockets pool to be empty');
-
-  agent.destroy();
-  server.close();
-  process.exit(0);
-}

test/parallel/test-http-agent-keepalive.js

@@ -4,6 +4,8 @@ const assert = require('assert');
 const http = require('http');
 const Agent = require('_http_agent').Agent;
 
+let name;
+
 const agent = new Agent({
   keepAlive: true,
   keepAliveMsecs: 1000,
@@ -28,14 +30,12 @@ const server = http.createServer(function(req, res) {
 function get(path, callback) {
   return http.get({
     host: 'localhost',
-    port: common.PORT,
+    port: server.address().port,
     agent: agent,
     path: path
   }, callback);
 }
 
-const name = 'localhost:' + common.PORT + ':';
-
 function checkDataAndSockets(body) {
   assert.equal(body.toString(), 'hello world');
   assert.equal(agent.sockets[name].length, 1);
@@ -106,7 +106,8 @@ function done() {
   process.exit(0);
 }
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
+  name = `localhost:${server.address().port}:`;
   // request first, and keep alive
   get('/first', function(res) {
     assert.equal(res.statusCode, 200);

test/parallel/test-http-agent-maxsockets-regress-4050.js

@@ -1,5 +1,5 @@
 'use strict';
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const http = require('http');
 
@@ -19,13 +19,13 @@ const server = http.createServer(function(req, res) {
 function get(path, callback) {
   return http.get({
     host: 'localhost',
-    port: common.PORT,
+    port: server.address().port,
     agent: agent,
     path: path
   }, callback);
 }
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   var finished = 0;
   const num_requests = 6;
   for (var i = 0; i < num_requests; i++) {

test/parallel/test-http-agent-maxsockets.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -17,7 +17,7 @@ var server = http.createServer(function(req, res) {
 function get(path, callback) {
   return http.get({
     host: 'localhost',
-    port: common.PORT,
+    port: server.address().port,
     agent: agent,
     path: path
   }, callback);
@@ -35,7 +35,7 @@ function done() {
   server.close();
 }
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   get('/1', function(res) {
     assert.equal(res.statusCode, 200);
     res.resume();

test/parallel/test-http-agent-no-protocol.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 var url = require('url');
@@ -14,8 +14,8 @@ process.on('exit', function() {
 var server = http.createServer(function(req, res) {
   res.end();
   request++;
-}).listen(common.PORT, '127.0.0.1', function() {
-  var opts = url.parse('http://127.0.0.1:' + common.PORT + '/');
+}).listen(0, '127.0.0.1', function() {
+  var opts = url.parse(`http://127.0.0.1:${this.address().port}/`);
 
   // remove the `protocol` field… the `http` module should fall back
   // to "http:", as defined by the global, default `http.Agent` instance.

test/parallel/test-http-agent-null.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -13,7 +13,7 @@ process.on('exit', function() {
 var server = http.createServer(function(req, res) {
   request++;
   res.end();
-}).listen(common.PORT, function() {
+}).listen(0, function() {
   var options = {
     agent: null,
     port: this.address().port

test/parallel/test-http-agent.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -12,11 +12,12 @@ var responses = 0;
 var N = 4;
 var M = 4;
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
+  const port = this.address().port;
   for (var i = 0; i < N; i++) {
     setTimeout(function() {
       for (var j = 0; j < M; j++) {
-        http.get({ port: common.PORT, path: '/' }, function(res) {
+        http.get({ port: port, path: '/' }, function(res) {
           console.log('%d %d', responses, res.statusCode);
           if (++responses == N * M) {
             console.error('Received all responses, closing server');

test/parallel/test-http-allow-req-after-204-res.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var http = require('http');
 var assert = require('assert');
 
@@ -23,7 +23,7 @@ function nextRequest() {
   console.error('writing request: %s', method);
 
   var request = http.request({
-    port: common.PORT,
+    port: server.address().port,
     method: method,
     path: '/'
   }, function(response) {
@@ -43,4 +43,4 @@ function nextRequest() {
   request.end();
 }
 
-server.listen(common.PORT, nextRequest);
+server.listen(0, nextRequest);

test/parallel/test-http-automatic-headers.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -9,12 +9,12 @@ var server = http.createServer(function(req, res) {
   res.setHeader('X-Content-Length', 'baz');
   res.end();
 });
-server.listen(common.PORT);
+server.listen(0);
 
 server.on('listening', function() {
-  var agent = new http.Agent({ port: common.PORT, maxSockets: 1 });
+  var agent = new http.Agent({ port: this.address().port, maxSockets: 1 });
   http.get({
-    port: common.PORT,
+    port: this.address().port,
     path: '/hello',
     agent: agent
   }, function(res) {

test/parallel/test-http-bind-twice.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -14,14 +14,13 @@ function dontCall() {
 }
 
 var server1 = http.createServer(dontCall);
-server1.listen(common.PORT, '127.0.0.1', function() {});
+server1.listen(0, '127.0.0.1', function() {
+  var server2 = http.createServer(dontCall);
+  server2.listen(this.address().port, '127.0.0.1', dontCall);
 
-var server2 = http.createServer(dontCall);
-server2.listen(common.PORT, '127.0.0.1', dontCall);
-
-server2.on('error', function(e) {
-  assert.equal(e.code, 'EADDRINUSE');
-  server1.close();
-  gotError = true;
+  server2.on('error', function(e) {
+    assert.equal(e.code, 'EADDRINUSE');
+    server1.close();
+    gotError = true;
+  });
 });
-

test/parallel/test-http-blank-header.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 var net = require('net');
@@ -18,8 +18,8 @@ var server = http.createServer(function(req, res) {
 });
 
 
-server.listen(common.PORT, function() {
-  var c = net.createConnection(common.PORT);
+server.listen(0, function() {
+  var c = net.createConnection(this.address().port);
 
   c.on('connect', function() {
     c.write('GET /blah HTTP/1.1\r\n' +

test/parallel/test-http-buffer-sanity.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -44,11 +44,11 @@ var web = http.Server(function(req, res) {
 
 var gotThanks = false;
 
-web.listen(common.PORT, function() {
+web.listen(0, function() {
   console.log('Making request');
 
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'GET',
     path: '/',
     headers: { 'content-length': buffer.length }

test/parallel/test-http-byteswritten.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -36,6 +36,6 @@ var httpServer = http.createServer(function(req, res) {
   res.end(body);
 });
 
-httpServer.listen(common.PORT, function() {
-  http.get({ port: common.PORT });
+httpServer.listen(0, function() {
+  http.get({ port: this.address().port });
 });

test/parallel/test-http-catch-uncaughtexception.js

@@ -13,8 +13,8 @@ process.on('uncaughtException', uncaughtCallback);
 const server = http.createServer(function(req, res) {
   res.writeHead(200, { 'Content-Type': 'text/plain' });
   res.end('bye');
-}).listen(common.PORT, function() {
-  http.get({ port: common.PORT }, function(res) {
+}).listen(0, function() {
+  http.get({ port: this.address().port }, function(res) {
     res.resume();
     throw new Error('get did fail');
   }).on('close', function() {

test/parallel/test-http-chunk-problem.js

@@ -10,7 +10,7 @@ if (!common.hasCrypto) {
 if (process.argv[2] === 'request') {
   const http = require('http');
   const options = {
-    port: common.PORT,
+    port: +process.argv[3],
     path: '/'
   };
 
@@ -39,11 +39,13 @@ const http = require('http');
 const cp = require('child_process');
 
 const filename = require('path').join(common.tmpDir, 'big');
+let server;
 
 function executeRequest(cb) {
   cp.exec([process.execPath,
            __filename,
            'request',
+           server.address().port,
            '|',
            process.execPath,
            __filename,
@@ -64,7 +66,7 @@ const ddcmd = common.ddCommand(filename, 10240);
 
 cp.exec(ddcmd, function(err, stdout, stderr) {
   if (err) throw err;
-  const server = http.createServer(function(req, res) {
+  server = http.createServer(function(req, res) {
     res.writeHead(200);
 
     // Create the subprocess
@@ -87,7 +89,7 @@ cp.exec(ddcmd, function(err, stdout, stderr) {
 
   });
 
-  server.listen(common.PORT, () => {
+  server.listen(0, () => {
     executeRequest(() => server.close());
   });
 });

test/parallel/test-http-chunked-304.js

@@ -23,8 +23,8 @@ function test(statusCode, next) {
     server.close();
   });
 
-  server.listen(common.PORT, function() {
-    var conn = net.createConnection(common.PORT, function() {
+  server.listen(0, function() {
+    var conn = net.createConnection(this.address().port, function() {
       conn.write('GET / HTTP/1.1\r\n\r\n');
 
       var resp = '';

test/parallel/test-http-chunked.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -17,12 +17,12 @@ var server = http.createServer(function(req, res) {
   res.writeHead(200, {'Content-Type': 'text/plain; charset=utf8'});
   res.end(UTF8_STRING, 'utf8');
 });
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   var data = '';
   var get = http.get({
     path: '/',
     host: 'localhost',
-    port: common.PORT
+    port: this.address().port
   }, function(x) {
     x.setEncoding('utf8');
     x.on('data', function(c) {data += c;});

test/parallel/test-http-client-abort-event.js

@@ -1,14 +1,14 @@
 'use strict';
+require('../common');
 var assert = require('assert');
 var http = require('http');
-var common = require('../common');
 var server = http.createServer(function(req, res) {
   res.end();
 });
 var count = 0;
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   var req = http.request({
-    port: common.PORT
+    port: this.address().port
   }, function() {
     assert(false, 'should not receive data');
   });

test/parallel/test-http-client-abort.js

@@ -1,5 +1,5 @@
 'use strict';
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const http = require('http');
 
@@ -27,12 +27,12 @@ var responses = 0;
 const N = 8;
 const requests = [];
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   console.log('Server listening.');
 
   for (var i = 0; i < N; i++) {
     console.log('Making client ' + i);
-    var options = { port: common.PORT, path: '/?id=' + i };
+    var options = { port: this.address().port, path: '/?id=' + i };
     var req = http.get(options, function(res) {
       console.log('Client response code ' + res.statusCode);
 

test/parallel/test-http-client-abort2.js

@@ -1,13 +1,13 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var http = require('http');
 
 var server = http.createServer(function(req, res) {
   res.end('Hello');
 });
 
-server.listen(common.PORT, function() {
-  var req = http.get({port: common.PORT}, function(res) {
+server.listen(0, function() {
+  var req = http.get({port: this.address().port}, function(res) {
     res.on('data', function(data) {
       req.abort();
       server.close();

test/parallel/test-http-client-agent.js

@@ -1,9 +1,9 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
-var name = http.globalAgent.getName({ port: common.PORT });
+var name;
 var max = 3;
 var count = 0;
 
@@ -18,7 +18,8 @@ var server = http.Server(function(req, res) {
     res.end('Hello, World!');
   }
 });
-server.listen(common.PORT, function() {
+server.listen(0, function() {
+  name = http.globalAgent.getName({ port: this.address().port });
   for (var i = 0; i < max; ++i) {
     request(i);
   }
@@ -26,7 +27,7 @@ server.listen(common.PORT, function() {
 
 function request(i) {
   var req = http.get({
-    port: common.PORT,
+    port: server.address().port,
     path: '/' + i
   }, function(res) {
     var socket = req.socket;

test/parallel/test-http-client-default-headers-exist.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -36,11 +36,11 @@ var server = http.createServer(function(req, res) {
     server.close();
 });
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   expectedMethods.forEach(function(method) {
     http.request({
       method: method,
-      port: common.PORT
+      port: server.address().port
     }).end();
   });
 });

test/parallel/test-http-client-encoding.js

@@ -1,16 +1,16 @@
 'use strict';
-var common = require('../common');
+require('../common');
 
 var http = require('http');
 
 http.createServer(function(req, res) {
   res.end('ok\n');
   this.close();
-}).listen(common.PORT, test);
+}).listen(0, test);
 
 function test() {
   http.request({
-    port: common.PORT,
+    port: this.address().port,
     encoding: 'utf8'
   }, function(res) {
     res.pipe(process.stdout);

test/parallel/test-http-client-get-url.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -15,8 +15,8 @@ var server = http.createServer(function(req, res) {
   seen_req = true;
 });
 
-server.listen(common.PORT, function() {
-  http.get('http://127.0.0.1:' + common.PORT + '/foo?bar');
+server.listen(0, function() {
+  http.get(`http://127.0.0.1:${this.address().port}/foo?bar`);
 });
 
 process.on('exit', function() {

test/parallel/test-http-client-parse-error.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var http = require('http');
@@ -17,11 +17,11 @@ net.createServer(function(c) {
     c.end('bad http - should trigger parse error\r\n');
     this.close();
   }
-}).listen(common.PORT, '127.0.0.1', function() {
+}).listen(0, '127.0.0.1', function() {
   for (var i = 0; i < 2; i++) {
     http.request({
       host: '127.0.0.1',
-      port: common.PORT,
+      port: this.address().port,
       method: 'GET',
       path: '/'
     }).on('error', function(e) {

test/parallel/test-http-client-race-2.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 var url = require('url');
@@ -27,14 +27,14 @@ var server = http.createServer(function(req, res) {
                 {'Content-Type': 'text/plain', 'Content-Length': body.length});
   res.end(body);
 });
-server.listen(common.PORT);
+server.listen(0);
 
 var body1 = '';
 var body2 = '';
 var body3 = '';
 
 server.on('listening', function() {
-  var client = http.createClient(common.PORT);
+  var client = http.createClient(this.address().port);
 
   //
   // Client #1 is assigned Parser #1
@@ -59,7 +59,7 @@ server.on('listening', function() {
         // parser that previously belonged to Client #1. But we're not finished
         // with Client #1 yet!
         //
-        var client2 = http.createClient(common.PORT);
+        var client2 = http.createClient(server.address().port);
 
         //
         // At this point, the bug would manifest itself and crash because the

test/parallel/test-http-client-race.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 var url = require('url');
@@ -13,13 +13,13 @@ var server = http.createServer(function(req, res) {
                 {'Content-Type': 'text/plain', 'Content-Length': body.length});
   res.end(body);
 });
-server.listen(common.PORT);
+server.listen(0);
 
 var body1 = '';
 var body2 = '';
 
 server.on('listening', function() {
-  var req1 = http.request({ port: common.PORT, path: '/1' });
+  var req1 = http.request({ port: this.address().port, path: '/1' });
   req1.end();
   req1.on('response', function(res1) {
     res1.setEncoding('utf8');
@@ -29,7 +29,7 @@ server.on('listening', function() {
     });
 
     res1.on('end', function() {
-      var req2 = http.request({ port: common.PORT, path: '/2' });
+      var req2 = http.request({ port: server.address().port, path: '/2' });
       req2.end();
       req2.on('response', function(res2) {
         res2.setEncoding('utf8');

test/parallel/test-http-client-reject-chunked-with-content-length.js

@@ -13,11 +13,11 @@ const server = net.createServer((socket) => {
   socket.write(reqstr);
 });
 
-server.listen(common.PORT, () => {
+server.listen(0, () => {
   // The callback should not be called because the server is sending
   // both a Content-Length header and a Transfer-Encoding: chunked
   // header, which is a violation of the HTTP spec.
-  const req = http.get({port: common.PORT}, (res) => {
+  const req = http.get({port: server.address().port}, (res) => {
     assert.fail(null, null, 'callback should not be called');
   });
   req.on('error', common.mustCall((err) => {

test/parallel/test-http-client-reject-cr-no-lf.js

@@ -13,10 +13,10 @@ const server = net.createServer((socket) => {
   socket.write(reqstr);
 });
 
-server.listen(common.PORT, () => {
+server.listen(0, () => {
   // The callback should not be called because the server is sending a
   // header field that ends only in \r with no following \n
-  const req = http.get({port: common.PORT}, (res) => {
+  const req = http.get({port: server.address().port}, (res) => {
     assert.fail(null, null, 'callback should not be called');
   });
   req.on('error', common.mustCall((err) => {

test/parallel/test-http-client-timeout-agent.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -8,7 +8,7 @@ var requests_sent = 0;
 var requests_done = 0;
 var options = {
   method: 'GET',
-  port: common.PORT,
+  port: undefined,
   host: '127.0.0.1',
 };
 
@@ -27,7 +27,8 @@ var server = http.createServer(function(req, res) {
   request_number += 1;
 });
 
-server.listen(options.port, options.host, function() {
+server.listen(0, options.host, function() {
+  options.port = this.address().port;
   var req;
 
   for (requests_sent = 0; requests_sent < 30; requests_sent += 1) {

test/parallel/test-http-client-timeout-event.js

@@ -5,7 +5,7 @@ var http = require('http');
 
 var options = {
   method: 'GET',
-  port: common.PORT,
+  port: undefined,
   host: '127.0.0.1',
   path: '/'
 };
@@ -14,7 +14,8 @@ var server = http.createServer(function(req, res) {
   // this space intentionally left blank
 });
 
-server.listen(options.port, options.host, function() {
+server.listen(0, options.host, function() {
+  options.port = this.address().port;
   var req = http.request(options, function(res) {
     // this space intentionally left blank
   });

test/parallel/test-http-client-timeout-with-data.js

@@ -13,7 +13,7 @@ process.on('exit', function() {
 
 const options = {
   method: 'GET',
-  port: common.PORT,
+  port: undefined,
   host: '127.0.0.1',
   path: '/'
 };
@@ -24,7 +24,8 @@ const server = http.createServer(function(req, res) {
   setTimeout(function() { res.end('*'); }, common.platformTimeout(100));
 });
 
-server.listen(options.port, options.host, function() {
+server.listen(0, options.host, function() {
+  options.port = this.address().port;
   const req = http.request(options, onresponse);
   req.end();
 

test/parallel/test-http-client-timeout.js

@@ -1,11 +1,11 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
 var options = {
   method: 'GET',
-  port: common.PORT,
+  port: undefined,
   host: '127.0.0.1',
   path: '/'
 };
@@ -14,7 +14,8 @@ var server = http.createServer(function(req, res) {
   // this space intentionally left blank
 });
 
-server.listen(options.port, options.host, function() {
+server.listen(0, options.host, function() {
+  options.port = this.address().port;
   var req = http.request(options, function(res) {
     // this space intentionally left blank
   });

test/parallel/test-http-client-upload-buf.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -23,11 +23,11 @@ var server = http.createServer(function(req, res) {
     res.end();
   });
 });
-server.listen(common.PORT);
+server.listen(0);
 
 server.on('listening', function() {
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'POST',
     path: '/'
   }, function(res) {

test/parallel/test-http-client-upload.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -24,11 +24,11 @@ var server = http.createServer(function(req, res) {
     res.end();
   });
 });
-server.listen(common.PORT);
+server.listen(0);
 
 server.on('listening', function() {
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'POST',
     path: '/'
   }, function(res) {

test/parallel/test-http-conn-reset.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 var net = require('net');
@@ -8,7 +8,7 @@ var caughtError = false;
 
 var options = {
   host: '127.0.0.1',
-  port: common.PORT
+  port: undefined
 };
 
 // start a tcp server that closes incoming connections immediately
@@ -16,10 +16,11 @@ var server = net.createServer(function(client) {
   client.destroy();
   server.close();
 });
-server.listen(options.port, options.host, onListen);
+server.listen(0, options.host, onListen);
 
 // do a GET request, expect it to fail
 function onListen() {
+  options.port = this.address().port;
   var req = http.request(options, function(res) {
     assert.ok(false, 'this should never run');
   });

test/parallel/test-http-connect-req-res.js

@@ -28,9 +28,9 @@ server.on('connect', common.mustCall(function(req, socket, firstBodyChunk) {
     socket.end(data);
   });
 }));
-server.listen(common.PORT, common.mustCall(function() {
+server.listen(0, common.mustCall(function() {
   const req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'CONNECT',
     path: 'example.com:443'
   }, function(res) {
@@ -43,7 +43,7 @@ server.listen(common.PORT, common.mustCall(function() {
     console.error('Client got CONNECT request');
 
     // Make sure this request got removed from the pool.
-    const name = 'localhost:' + common.PORT;
+    const name = 'localhost:' + server.address().port;
     assert(!http.globalAgent.sockets.hasOwnProperty(name));
     assert(!http.globalAgent.requests.hasOwnProperty(name));
 

test/parallel/test-http-connect.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -25,9 +25,9 @@ server.on('connect', function(req, socket, firstBodyChunk) {
     socket.end(data);
   });
 });
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'CONNECT',
     path: 'google.com:443'
   }, function(res) {
@@ -44,7 +44,7 @@ server.listen(common.PORT, function() {
     clientGotConnect = true;
 
     // Make sure this request got removed from the pool.
-    var name = 'localhost:' + common.PORT;
+    var name = 'localhost:' + server.address().port;
     assert(!http.globalAgent.sockets.hasOwnProperty(name));
     assert(!http.globalAgent.requests.hasOwnProperty(name));
 

test/parallel/test-http-content-length.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -46,11 +46,11 @@ var server = http.createServer(function(req, res) {
   if (totalRequests === receivedRequests) server.close();
 });
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   var req;
 
   req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'POST',
     path: '/multiple-writes'
   });
@@ -63,7 +63,7 @@ server.listen(common.PORT, function() {
   });
 
   req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'POST',
     path: '/end-with-data'
   });
@@ -75,7 +75,7 @@ server.listen(common.PORT, function() {
   });
 
   req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'POST',
     path: '/empty'
   });

test/parallel/test-http-contentLength0.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var http = require('http');
 
 // Simple test of Node's HTTP Client choking on a response
@@ -11,9 +11,9 @@ var s = http.createServer(function(req, res) {
   res.writeHead(200, {'Content-Length': '0 '});
   res.end();
 });
-s.listen(common.PORT, function() {
+s.listen(0, function() {
 
-  var request = http.request({ port: common.PORT }, function(response) {
+  var request = http.request({ port: this.address().port }, function(response) {
     console.log('STATUS: ' + response.statusCode);
     s.close();
     response.resume();

test/parallel/test-http-createConnection.js

@@ -6,7 +6,7 @@ const assert = require('assert');
 
 const server = http.createServer(common.mustCall(function(req, res) {
   res.end();
-}, 4)).listen(common.PORT, '127.0.0.1', function() {
+}, 4)).listen(0, '127.0.0.1', function() {
   let fn = common.mustCall(createConnection);
   http.get({ createConnection: fn }, function(res) {
     res.resume();
@@ -33,17 +33,17 @@ const server = http.createServer(common.mustCall(function(req, res) {
 });
 
 function createConnection() {
-  return net.createConnection(common.PORT, '127.0.0.1');
+  return net.createConnection(server.address().port, '127.0.0.1');
 }
 
 function createConnectionAsync(options, cb) {
   setImmediate(function() {
-    cb(null, net.createConnection(common.PORT, '127.0.0.1'));
+    cb(null, net.createConnection(server.address().port, '127.0.0.1'));
   });
 }
 
 function createConnectionBoth1(options, cb) {
-  const socket = net.createConnection(common.PORT, '127.0.0.1');
+  const socket = net.createConnection(server.address().port, '127.0.0.1');
   setImmediate(function() {
     cb(null, socket);
   });
@@ -51,7 +51,7 @@ function createConnectionBoth1(options, cb) {
 }
 
 function createConnectionBoth2(options, cb) {
-  const socket = net.createConnection(common.PORT, '127.0.0.1');
+  const socket = net.createConnection(server.address().port, '127.0.0.1');
   cb(null, socket);
   return socket;
 }

test/parallel/test-http-date-header.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -13,12 +13,12 @@ var server = http.createServer(function(req, res) {
   });
   res.end(testResBody);
 });
-server.listen(common.PORT);
+server.listen(0);
 
 
 server.addListener('listening', function() {
   var options = {
-    port: common.PORT,
+    port: this.address().port,
     path: '/',
     method: 'GET'
   };

test/parallel/test-http-default-encoding.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -18,9 +18,9 @@ var server = http.Server(function(req, res) {
 
 });
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   http.request({
-    port: common.PORT,
+    port: this.address().port,
     path: '/',
     method: 'POST'
   }, function(res) {

test/parallel/test-http-default-port.js

@@ -1,8 +1,6 @@
 'use strict';
 const common = require('../common');
 const http = require('http');
-const PORT = common.PORT;
-const SSLPORT = common.PORT + 1;
 const assert = require('assert');
 const hostExpect = 'localhost';
 const fs = require('fs');
@@ -29,18 +27,18 @@ process.on('exit', function() {
   console.log('ok');
 });
 
-http.globalAgent.defaultPort = PORT;
 http.createServer(function(req, res) {
   assert.equal(req.headers.host, hostExpect);
-  assert.equal(req.headers['x-port'], PORT);
+  assert.equal(req.headers['x-port'], this.address().port);
   res.writeHead(200);
   res.end('ok');
   this.close();
-}).listen(PORT, function() {
+}).listen(0, function() {
+  http.globalAgent.defaultPort = this.address().port;
   http.get({
     host: 'localhost',
     headers: {
-      'x-port': PORT
+      'x-port': this.address().port
     }
   }, function(res) {
     gotHttpResp = true;
@@ -49,19 +47,19 @@ http.createServer(function(req, res) {
 });
 
 if (common.hasCrypto) {
-  https.globalAgent.defaultPort = SSLPORT;
   https.createServer(options, function(req, res) {
     assert.equal(req.headers.host, hostExpect);
-    assert.equal(req.headers['x-port'], SSLPORT);
+    assert.equal(req.headers['x-port'], this.address().port);
     res.writeHead(200);
     res.end('ok');
     this.close();
-  }).listen(SSLPORT, function() {
+  }).listen(0, function() {
+    https.globalAgent.defaultPort = this.address().port;
     https.get({
       host: 'localhost',
       rejectUnauthorized: false,
       headers: {
-        'x-port': SSLPORT
+        'x-port': this.address().port
       }
     }, function(res) {
       gotHttpsResp = true;

test/parallel/test-http-destroyed-socket-write2.js

@@ -12,9 +12,9 @@ var server = http.createServer(function(req, res) {
   });
 });
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     path: '/',
     method: 'POST'
   });

test/parallel/test-http-double-content-length.js

@@ -17,9 +17,9 @@ server.on('clientError', common.mustCall((err, socket) => {
   socket.destroy();
 }));
 
-server.listen(common.PORT, () => {
+server.listen(0, () => {
   const req = http.get({
-    port: common.PORT,
+    port: server.address().port,
     // Send two content-length header values.
     headers: {'Content-Length': [1, 2]}},
     (res) => {

test/parallel/test-http-end-throw-socket-handling.js

@@ -16,9 +16,9 @@ const server = http.createServer((req, res) => {
   res.end('ok');
 });
 
-server.listen(common.PORT, common.mustCall(() => {
+server.listen(0, common.mustCall(() => {
   for (let i = 0; i < 10; i++) {
-    const options = { port: common.PORT };
+    const options = { port: server.address().port };
     const req = http.request(options, (res) => {
       res.resume();
       res.on('end', common.mustCall(() => {

test/parallel/test-http-eof-on-connect.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var net = require('net');
 var http = require('http');
 
@@ -8,10 +8,10 @@ var http = require('http');
 // reproduceable on the first packet on the first connection to a server.
 
 var server = http.createServer(function(req, res) {});
-server.listen(common.PORT);
+server.listen(0);
 
 server.on('listening', function() {
-  net.createConnection(common.PORT).on('connect', function() {
+  net.createConnection(this.address().port).on('connect', function() {
     this.destroy();
   }).on('close', function() {
     server.close();

test/parallel/test-http-exceptions.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var http = require('http');
 
 var server = http.createServer(function(req, res) {
@@ -9,9 +9,9 @@ var server = http.createServer(function(req, res) {
   res.end();
 });
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   for (var i = 0; i < 4; i += 1) {
-    http.get({ port: common.PORT, path: '/busy/' + i });
+    http.get({ port: this.address().port, path: '/busy/' + i });
   }
 });
 

test/parallel/test-http-expect-continue.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
@@ -28,12 +28,12 @@ server.on('checkContinue', function(req, res) {
     handler(req, res);
   }, 100);
 });
-server.listen(common.PORT);
+server.listen(0);
 
 
 server.on('listening', function() {
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'POST',
     path: '/world',
     headers: { 'Expect': '100-continue' }

test/parallel/test-http-expect-handling.js

@@ -13,11 +13,11 @@ const s = http.createServer(function(req, res) {
   throw new Error('this should never be executed');
 });
 
-s.listen(common.PORT, nextTest);
+s.listen(0, nextTest);
 
 function nextTest() {
   const options = {
-    port: common.PORT,
+    port: s.address().port,
     headers: { 'Expect': 'meoww' }
   };
 

test/parallel/test-http-extra-response.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 var net = require('net');
@@ -44,8 +44,8 @@ var server = net.createServer(function(socket) {
 });
 
 
-server.listen(common.PORT, function() {
-  http.get({ port: common.PORT }, function(res) {
+server.listen(0, function() {
+  http.get({ port: this.address().port }, function(res) {
     var buffer = '';
     console.log('Got res code: ' + res.statusCode);
 

test/parallel/test-http-flush-headers.js

@@ -1,5 +1,5 @@
 'use strict';
-const common = require('../common');
+require('../common');
 const assert = require('assert');
 const http = require('http');
 
@@ -9,11 +9,11 @@ server.on('request', function(req, res) {
   res.end('ok');
   server.close();
 });
-server.listen(common.PORT, '127.0.0.1', function() {
+server.listen(0, '127.0.0.1', function() {
   const req = http.request({
     method: 'GET',
     host: '127.0.0.1',
-    port: common.PORT,
+    port: this.address().port,
   });
   req.setHeader('foo', 'bar');
   req.flushHeaders();

test/parallel/test-http-flush-response-headers.js

@@ -10,11 +10,11 @@ server.on('request', function(req, res) {
   res.flushHeaders();
   res.flushHeaders(); // Should be idempotent.
 });
-server.listen(common.PORT, common.localhostIPv4, function() {
+server.listen(0, common.localhostIPv4, function() {
   var req = http.request({
     method: 'GET',
     host: common.localhostIPv4,
-    port: common.PORT,
+    port: this.address().port,
   }, onResponse);
 
   req.end();

test/parallel/test-http-flush.js

@@ -1,15 +1,15 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var http = require('http');
 
 http.createServer(function(req, res) {
   res.end('ok');
   this.close();
-}).listen(common.PORT, '127.0.0.1', function() {
+}).listen(0, '127.0.0.1', function() {
   var req = http.request({
     method: 'POST',
     host: '127.0.0.1',
-    port: common.PORT,
+    port: this.address().port,
   });
   req.flush();  // Flush the request headers.
   req.flush();  // Should be idempotent.

test/parallel/test-http-full-response.js

@@ -20,7 +20,7 @@ var server = http.createServer(function(req, res) {
 var runs = 0;
 
 function runAb(opts, callback) {
-  var command = 'ab ' + opts + ' http://127.0.0.1:' + common.PORT + '/';
+  var command = `ab ${opts} http://127.0.0.1:${server.address().port}/`;
   exec(command, function(err, stdout, stderr) {
     if (err) {
       if (/ab|apr/mi.test(stderr)) {
@@ -49,7 +49,7 @@ function runAb(opts, callback) {
   });
 }
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   runAb('-c 1 -n 10', function() {
     console.log('-c 1 -n 10 okay');
 

test/parallel/test-http-get-pipeline-problem.js

@@ -34,13 +34,13 @@ var server = http.Server(function(req, res) {
 });
 
 
-server.listen(common.PORT, function() {
+server.listen(0, function() {
   for (var i = 0; i < total; i++) {
     (function() {
       var x = i;
 
       var opts = {
-        port: common.PORT,
+        port: server.address().port,
         headers: { connection: 'close' }
       };
 

test/parallel/test-http-head-request.js

@@ -1,15 +1,11 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 var http = require('http');
 
-
 var body = 'hello world\n';
-var id = 0;
 
 function test(headers) {
-  var port = common.PORT + id++;
-
   var server = http.createServer(function(req, res) {
     console.error('req: %s headers: %j', req.method, headers);
     res.writeHead(200, headers);
@@ -19,9 +15,9 @@ function test(headers) {
 
   var gotEnd = false;
 
-  server.listen(port, function() {
+  server.listen(0, function() {
     var request = http.request({
-      port: port,
+      port: this.address().port,
       method: 'HEAD',
       path: '/'
     }, function(response) {

test/parallel/test-http-head-response-has-no-body-end.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var http = require('http');
@@ -12,13 +12,13 @@ var server = http.createServer(function(req, res) {
   res.writeHead(200);
   res.end('FAIL'); // broken: sends FAIL from hot path.
 });
-server.listen(common.PORT);
+server.listen(0);
 
 var responseComplete = false;
 
 server.on('listening', function() {
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'HEAD',
     path: '/'
   }, function(res) {

test/parallel/test-http-head-response-has-no-body.js

@@ -1,5 +1,5 @@
 'use strict';
-var common = require('../common');
+require('../common');
 var assert = require('assert');
 
 var http = require('http');
@@ -12,13 +12,13 @@ var server = http.createServer(function(req, res) {
   res.writeHead(200); // broken: defaults to TE chunked
   res.end();
 });
-server.listen(common.PORT);
+server.listen(0);
 
 var responseComplete = false;
 
 server.on('listening', function() {
   var req = http.request({
-    port: common.PORT,
+    port: this.address().port,
     method: 'HEAD',
     path: '/'
   }, function(res) {