dns: type check for dns.setServers argument.

Added type check for argument for dns.setServers and dnsPromises.setServers.

PR-URL: https://github.com/nodejs/node/pull/21944
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/test/parallel/test-dns-setservers-type-check.js b/test/parallel/test-dns-setservers-type-check.js
new file mode 100644
index 0000000000..256c029427
--- /dev/null
+++ b/test/parallel/test-dns-setservers-type-check.js
@@ -0,0 +1,87 @@
+'use strict';
+require('../common');
+const { addresses } = require('../common/internet');
+const assert = require('assert');
+const dns = require('dns');
+const resolver = new dns.promises.Resolver();
+const dnsPromises = dns.promises;
+const promiseResolver = new dns.promises.Resolver();
+
+{
+  [
+    null,
+    undefined,
+    Number(addresses.DNS4_SERVER),
+    addresses.DNS4_SERVER,
+    {
+      address: addresses.DNS4_SERVER
+    }
+  ].forEach((val) => {
+    const errObj = {
+      code: 'ERR_INVALID_ARG_TYPE',
+      name: 'TypeError [ERR_INVALID_ARG_TYPE]',
+      message: 'The "servers" argument must be of type Array. Received type ' +
+      typeof val
+    };
+    assert.throws(
+      () => {
+        dns.setServers(val);
+      }, errObj
+    );
+    assert.throws(
+      () => {
+        resolver.setServers(val);
+      }, errObj
+    );
+    assert.throws(
+      () => {
+        dnsPromises.setServers(val);
+      }, errObj
+    );
+    assert.throws(
+      () => {
+        promiseResolver.setServers(val);
+      }, errObj
+    );
+  });
+}
+
+{
+  [
+    [null],
+    [undefined],
+    [Number(addresses.DNS4_SERVER)],
+    [
+      {
+        address: addresses.DNS4_SERVER
+      }
+    ]
+  ].forEach((val) => {
+    const errObj = {
+      code: 'ERR_INVALID_ARG_TYPE',
+      name: 'TypeError [ERR_INVALID_ARG_TYPE]',
+      message: 'The "servers[0]" argument must be of type string. ' +
+               `Received type ${typeof val[0]}`
+    };
+    assert.throws(
+      () => {
+        dns.setServers(val);
+      }, errObj
+    );
+    assert.throws(
+      () => {
+        resolver.setServers(val);
+      }, errObj
+    );
+    assert.throws(
+      () => {
+        dnsPromises.setServers(val);
+      }, errObj
+    );
+    assert.throws(
+      () => {
+        promiseResolver.setServers(val);
+      }, errObj
+    );
+  });
+}