From 0623aabbe12cd288d82ef330654193a5edfcc3fa Mon Sep 17 00:00:00 2001
From: Masashi Hirano <cherrydog07@gmail.com>
Date: Mon, 17 Sep 2018 17:57:08 +0900
Subject: [PATCH] test: add tests to check error in dns.lookupService.

Added tests to check error in dns.lookupService to
increase coverage.

PR-URL: https://github.com/nodejs/node/pull/22908
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Weijia Wang <starkwang@126.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 test/parallel/test-dns-lookupService.js | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 test/parallel/test-dns-lookupService.js

diff --git a/test/parallel/test-dns-lookupService.js b/test/parallel/test-dns-lookupService.js
new file mode 100644
index 00000000000000..92fce6cbd3f189
--- /dev/null
+++ b/test/parallel/test-dns-lookupService.js
@@ -0,0 +1,20 @@
+// Flags: --expose-internals
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const { internalBinding } = require('internal/test/binding');
+const cares = internalBinding('cares_wrap');
+const { UV_ENOENT } = internalBinding('uv');
+const dns = require('dns');
+
+// Stub `getnameinfo` to *always* error.
+cares.getnameinfo = () => UV_ENOENT;
+
+assert.throws(
+  () => dns.lookupService('127.0.0.1', 80, common.mustNotCall()),
+  {
+    code: 'ENOENT',
+    message: 'getnameinfo ENOENT 127.0.0.1',
+    syscall: 'getnameinfo'
+  }
+);