dns: add promisified dns module

PR-URL: https://github.com/nodejs/node/pull/21264
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

1 files changed, 31 insertions, 5 deletions

diff --git a/test/parallel/test-c-ares.js b/test/parallel/test-c-ares.js
index 8ba221ca99..59ae40b2b8 100644
--- a/test/parallel/test-c-ares.js
+++ b/test/parallel/test-c-ares.js
@@ -23,8 +23,26 @@
 const common = require('../common');
 const assert = require('assert');
 
+common.crashOnUnhandledRejection();
+
 const dns = require('dns');
+const dnsPromises = dns.promises;
+
+(async function() {
+  let res;
+
+  res = await dnsPromises.lookup(null);
+  assert.strictEqual(res.address, null);
+  assert.strictEqual(res.family, 4);
+
+  res = await dnsPromises.lookup('127.0.0.1');
+  assert.strictEqual(res.address, '127.0.0.1');
+  assert.strictEqual(res.family, 4);
 
+  res = await dnsPromises.lookup('::1');
+  assert.strictEqual(res.address, '::1');
+  assert.strictEqual(res.family, 6);
+})();
 
 // Try resolution without callback
 
@@ -52,14 +70,18 @@ dns.lookup('::1', common.mustCall((error, result, addressType) => {
   // Try calling resolve with an unsupported type that's an object key
   'toString'
 ].forEach((val) => {
+  const err = {
+    code: 'ERR_INVALID_OPT_VALUE',
+    type: TypeError,
+    message: `The value "${val}" is invalid for option "rrtype"`
+  };
+
   common.expectsError(
     () => dns.resolve('www.google.com', val),
-    {
-      code: 'ERR_INVALID_OPT_VALUE',
-      type: TypeError,
-      message: `The value "${val}" is invalid for option "rrtype"`
-    }
+    err
   );
+
+  common.expectsError(() => dnsPromises.resolve('www.google.com', val), err);
 });
 
 // Windows doesn't usually have an entry for localhost 127.0.0.1 in
@@ -70,4 +92,8 @@ if (!common.isWindows) {
     assert.ifError(error);
     assert.ok(Array.isArray(domains));
   }));
+
+  (async function() {
+    assert.ok(Array.isArray(await dnsPromises.reverse('127.0.0.1')));
+  })();
 }