From 743c28104f3db504963409e8e91700e430131221 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Fri, 7 Feb 2020 05:54:01 -1000
Subject: [PATCH] test,dns: add coverage for dns exception

Add test coverage for dns.promises.resolve() handling an exception from
c-ares.

Refs: https://coverage.nodejs.org/coverage-d213f21c72f77da6/lib/internal/dns/promises.js.html#L198

PR-URL: https://github.com/nodejs/node/pull/31678
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
---
 test/parallel/test-dns-resolve-promises.js | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 test/parallel/test-dns-resolve-promises.js

diff --git a/test/parallel/test-dns-resolve-promises.js b/test/parallel/test-dns-resolve-promises.js
new file mode 100644
index 00000000000000..783ed2a709edb6
--- /dev/null
+++ b/test/parallel/test-dns-resolve-promises.js
@@ -0,0 +1,20 @@
+// Flags: --expose-internals
+'use strict';
+require('../common');
+const assert = require('assert');
+const { internalBinding } = require('internal/test/binding');
+const cares = internalBinding('cares_wrap');
+const { UV_EPERM } = internalBinding('uv');
+const dnsPromises = require('dns').promises;
+
+// Stub cares to force an error so we can test DNS error code path.
+cares.ChannelWrap.prototype.queryA = () => UV_EPERM;
+
+assert.rejects(
+  dnsPromises.resolve('example.org'),
+  {
+    code: 'EPERM',
+    syscall: 'queryA',
+    hostname: 'example.org'
+  }
+);