From 9a41646c36b9beeec8f50b3f092506650cdc2772 Mon Sep 17 00:00:00 2001
From: cjihrig <cjihrig@gmail.com>
Date: Wed, 7 Aug 2019 21:59:51 -0400
Subject: [PATCH] dns: update lookupService() first arg name

The first argument to lookupService() should be an IP address,
and is named "address" in the documentation. This commit updates
the code to match the documentation and provide less confusing
errors.
---
 lib/dns.js                   | 15 +++++++--------
 lib/internal/dns/promises.js | 10 +++++-----
 test/parallel/test-dns.js    | 12 ++++++------
 3 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/lib/dns.js b/lib/dns.js
index 835eb91ee16b..b5a528ead137 100644
--- a/lib/dns.js
+++ b/lib/dns.js
@@ -164,13 +164,12 @@ function onlookupservice(err, hostname, service) {
 }
 
 
-// lookupService(address, port, callback)
-function lookupService(hostname, port, callback) {
+function lookupService(address, port, callback) {
   if (arguments.length !== 3)
-    throw new ERR_MISSING_ARGS('hostname', 'port', 'callback');
+    throw new ERR_MISSING_ARGS('address', 'port', 'callback');
 
-  if (isIP(hostname) === 0)
-    throw new ERR_INVALID_OPT_VALUE('hostname', hostname);
+  if (isIP(address) === 0)
+    throw new ERR_INVALID_OPT_VALUE('address', address);
 
   if (!isLegalPort(port))
     throw new ERR_SOCKET_BAD_PORT(port);
@@ -182,12 +181,12 @@ function lookupService(hostname, port, callback) {
 
   const req = new GetNameInfoReqWrap();
   req.callback = callback;
-  req.hostname = hostname;
+  req.hostname = address;
   req.port = port;
   req.oncomplete = onlookupservice;
 
-  const err = cares.getnameinfo(req, hostname, port);
-  if (err) throw dnsException(err, 'getnameinfo', hostname);
+  const err = cares.getnameinfo(req, address, port);
+  if (err) throw dnsException(err, 'getnameinfo', address);
   return req;
 }
 
diff --git a/lib/internal/dns/promises.js b/lib/internal/dns/promises.js
index 2969721355ad..306d5eee4773 100644
--- a/lib/internal/dns/promises.js
+++ b/lib/internal/dns/promises.js
@@ -151,17 +151,17 @@ function createLookupServicePromise(hostname, port) {
   });
 }
 
-function lookupService(hostname, port) {
+function lookupService(address, port) {
   if (arguments.length !== 2)
-    throw new ERR_MISSING_ARGS('hostname', 'port');
+    throw new ERR_MISSING_ARGS('address', 'port');
 
-  if (isIP(hostname) === 0)
-    throw new ERR_INVALID_OPT_VALUE('hostname', hostname);
+  if (isIP(address) === 0)
+    throw new ERR_INVALID_OPT_VALUE('address', address);
 
   if (!isLegalPort(port))
     throw new ERR_SOCKET_BAD_PORT(port);
 
-  return createLookupServicePromise(hostname, +port);
+  return createLookupServicePromise(address, +port);
 }
 
 
diff --git a/test/parallel/test-dns.js b/test/parallel/test-dns.js
index 7d0a298dd6d6..e854574a2eab 100644
--- a/test/parallel/test-dns.js
+++ b/test/parallel/test-dns.js
@@ -265,29 +265,29 @@ dns.lookup('', {
   const err = {
     code: 'ERR_MISSING_ARGS',
     type: TypeError,
-    message: 'The "hostname", "port", and "callback" arguments must be ' +
+    message: 'The "address", "port", and "callback" arguments must be ' +
     'specified'
   };
 
   common.expectsError(() => dns.lookupService('0.0.0.0'), err);
-  err.message = 'The "hostname" and "port" arguments must be specified';
+  err.message = 'The "address" and "port" arguments must be specified';
   common.expectsError(() => dnsPromises.lookupService('0.0.0.0'), err);
 }
 
 {
-  const invalidHost = 'fasdfdsaf';
+  const invalidAddress = 'fasdfdsaf';
   const err = {
     code: 'ERR_INVALID_OPT_VALUE',
     type: TypeError,
-    message: `The value "${invalidHost}" is invalid for option "hostname"`
+    message: `The value "${invalidAddress}" is invalid for option "address"`
   };
 
   common.expectsError(() => {
-    dnsPromises.lookupService(invalidHost, 0);
+    dnsPromises.lookupService(invalidAddress, 0);
   }, err);
 
   common.expectsError(() => {
-    dns.lookupService(invalidHost, 0, common.mustNotCall());
+    dns.lookupService(invalidAddress, 0, common.mustNotCall());
   }, err);
 }