dns: fix inconsistent (hostname vs host)

Fixes: https://github.com/nodejs/node/issues/20892
PR-URL: https://github.com/nodejs/node/pull/23572
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

lib/dns.js

@@ -152,21 +152,21 @@ Object.defineProperty(lookup, customPromisifyArgs,
                       { value: ['address', 'family'], enumerable: false });
 
 
-function onlookupservice(err, host, service) {
+function onlookupservice(err, hostname, service) {
   if (err)
-    return this.callback(dnsException(err, 'getnameinfo', this.host));
+    return this.callback(dnsException(err, 'getnameinfo', this.hostname));
 
-  this.callback(null, host, service);
+  this.callback(null, hostname, service);
 }
 
 
 // lookupService(address, port, callback)
-function lookupService(host, port, callback) {
+function lookupService(hostname, port, callback) {
   if (arguments.length !== 3)
-    throw new ERR_MISSING_ARGS('host', 'port', 'callback');
+    throw new ERR_MISSING_ARGS('hostname', 'port', 'callback');
 
-  if (isIP(host) === 0)
+  if (isIP(hostname) === 0)
-    throw new ERR_INVALID_OPT_VALUE('host', host);
+    throw new ERR_INVALID_OPT_VALUE('hostname', hostname);
 
   if (!isLegalPort(port))
     throw new ERR_SOCKET_BAD_PORT(port);
@@ -178,12 +178,12 @@ function lookupService(host, port, callback) {
 
   var req = new GetNameInfoReqWrap();
   req.callback = callback;
-  req.host = host;
+  req.hostname = hostname;
   req.port = port;
   req.oncomplete = onlookupservice;
 
-  var err = cares.getnameinfo(req, host, port);
+  var err = cares.getnameinfo(req, hostname, port);
-  if (err) throw dnsException(err, 'getnameinfo', host);
+  if (err) throw dnsException(err, 'getnameinfo', hostname);
   return req;
 }
 

lib/internal/dns/promises.js

@@ -129,34 +129,34 @@ function onlookupservice(err, hostname, service) {
   this.resolve({ hostname, service });
 }
 
-function createLookupServicePromise(host, port) {
+function createLookupServicePromise(hostname, port) {
   return new Promise((resolve, reject) => {
     const req = new GetNameInfoReqWrap();
 
-    req.host = host;
+    req.hostname = hostname;
     req.port = port;
     req.oncomplete = onlookupservice;
     req.resolve = resolve;
     req.reject = reject;
 
-    const err = getnameinfo(req, host, port);
+    const err = getnameinfo(req, hostname, port);
 
     if (err)
-      reject(dnsException(err, 'getnameinfo', host));
+      reject(dnsException(err, 'getnameinfo', hostname));
   });
 }
 
-function lookupService(host, port) {
+function lookupService(hostname, port) {
   if (arguments.length !== 2)
-    throw new ERR_MISSING_ARGS('host', 'port');
+    throw new ERR_MISSING_ARGS('hostname', 'port');
 
-  if (isIP(host) === 0)
+  if (isIP(hostname) === 0)
-    throw new ERR_INVALID_OPT_VALUE('host', host);
+    throw new ERR_INVALID_OPT_VALUE('hostname', hostname);
 
   if (!isLegalPort(port))
     throw new ERR_SOCKET_BAD_PORT(port);
 
-  return createLookupServicePromise(host, +port);
+  return createLookupServicePromise(hostname, +port);
 }
 
 

test/common/dns.js

@@ -291,12 +291,12 @@ const mockedErrorCode = 'ENOTFOUND';
 const mockedSysCall = 'getaddrinfo';
 
 function errorLookupMock(code = mockedErrorCode, syscall = mockedSysCall) {
-  return function lookupWithError(host, dnsopts, cb) {
+  return function lookupWithError(hostname, dnsopts, cb) {
-    const err = new Error(`${syscall} ${code} ${host}`);
+    const err = new Error(`${syscall} ${code} ${hostname}`);
     err.code = code;
     err.errno = code;
     err.syscall = syscall;
-    err.hostname = host;
+    err.hostname = hostname;
     cb(err);
   };
 }

test/parallel/test-dns.js

@@ -261,11 +261,12 @@ dns.lookup('', {
   const err = {
     code: 'ERR_MISSING_ARGS',
     type: TypeError,
-    message: 'The "host", "port", and "callback" arguments must be specified'
+    message: 'The "hostname", "port", and "callback" arguments must be ' +
+    'specified'
   };
 
   common.expectsError(() => dns.lookupService('0.0.0.0'), err);
-  err.message = 'The "host" and "port" arguments must be specified';
+  err.message = 'The "hostname" and "port" arguments must be specified';
   common.expectsError(() => dnsPromises.lookupService('0.0.0.0'), err);
 }
 
@@ -274,7 +275,7 @@ dns.lookup('', {
   const err = {
     code: 'ERR_INVALID_OPT_VALUE',
     type: TypeError,
-    message: `The value "${invalidHost}" is invalid for option "host"`
+    message: `The value "${invalidHost}" is invalid for option "hostname"`
   };
 
   common.expectsError(() => {