net: do not manipulate potential user code

lib/net.js

@@ -971,12 +971,6 @@ function lookupAndConnect(self, options) {
         // net.createConnection() creates a net.Socket object and immediately
         // calls net.Socket.connect() on it (that's us). There are no event
         // listeners registered yet so defer the error event to the next tick.
-        // TODO(BridgeAR): The error could either originate from user code or
-        // by the C++ layer. The port is never the cause for the error as it is
-        // not used in the lookup. We should probably just remove this.
-        err.host = options.host;
-        err.port = options.port;
-        err.message = err.message + ' ' + options.host + ':' + options.port;
         process.nextTick(connectErrorNT, self, err);
       } else if (addressType !== 4 && addressType !== 6) {
         err = new ERR_INVALID_ADDRESS_FAMILY(addressType,

test/parallel/test-net-better-error-messages-port-hostname.js

@@ -6,7 +6,6 @@
 
 const common = require('../common');
 const net = require('net');
-const assert = require('assert');
 
 const { addresses } = require('../common/internet');
 const {
@@ -23,8 +22,9 @@ const c = net.createConnection({
 
 c.on('connect', common.mustNotCall());
 
-c.on('error', common.mustCall(function(e) {
-  assert.strictEqual(e.code, mockedErrorCode);
-  assert.strictEqual(e.port, 0);
-  assert.strictEqual(e.hostname, addresses.INVALID_HOST);
+c.on('error', common.expectsError({
+  code: mockedErrorCode,
+  hostname: addresses.INVALID_HOST,
+  port: undefined,
+  host: undefined
 }));

test/parallel/test-net-connect-immediate-finish.js

@@ -26,7 +26,6 @@
 // 'connect' and defer the handling until the 'connect' event is handled.
 
 const common = require('../common');
-const assert = require('assert');
 const net = require('net');
 
 const { addresses } = require('../common/internet');
@@ -42,13 +41,14 @@ const client = net.connect({
   lookup: common.mustCall(errorLookupMock())
 }, common.mustNotCall());
 
-client.once('error', common.mustCall((err) => {
-  assert(err);
-  assert.strictEqual(err.code, err.errno);
-  assert.strictEqual(err.code, mockedErrorCode);
-  assert.strictEqual(err.host, err.hostname);
-  assert.strictEqual(err.host, addresses.INVALID_HOST);
-  assert.strictEqual(err.syscall, mockedSysCall);
+client.once('error', common.expectsError({
+  code: mockedErrorCode,
+  errno: mockedErrorCode,
+  syscall: mockedSysCall,
+  hostname: addresses.INVALID_HOST,
+  message: 'getaddrinfo ENOTFOUND something.invalid',
+  port: undefined,
+  host: undefined
 }));
 
 client.end();