test: various test improvements

* Favor strictEqual
* Use const where appropriate
* Modernize where possible

PR-URL: https://github.com/nodejs/node/pull/8468
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/test/parallel/test-c-ares.js b/test/parallel/test-c-ares.js
index 0da5d5210c..2eb824b5df 100644
--- a/test/parallel/test-c-ares.js
+++ b/test/parallel/test-c-ares.js
@@ -7,30 +7,29 @@ const dns = require('dns');
 
 // Try resolution without callback
 
-dns.lookup(null, common.mustCall(function(error, result, addressType) {
+dns.lookup(null, common.mustCall((error, result, addressType) => {
+  assert.ifError(error);
   assert.strictEqual(null, result);
   assert.strictEqual(4, addressType);
 }));
 
-dns.lookup('127.0.0.1', common.mustCall(function(error, result, addressType) {
+dns.lookup('127.0.0.1', common.mustCall((error, result, addressType) => {
+  assert.ifError(error);
   assert.strictEqual('127.0.0.1', result);
   assert.strictEqual(4, addressType);
 }));
 
-dns.lookup('::1', common.mustCall(function(error, result, addressType) {
+dns.lookup('::1', common.mustCall((error, result, addressType) => {
+  assert.ifError(error);
   assert.strictEqual('::1', result);
   assert.strictEqual(6, addressType);
 }));
 
 // Try calling resolve with an unsupported type.
-assert.throws(function() {
-  dns.resolve('www.google.com', 'HI');
-}, /Unknown type/);
+assert.throws(() => dns.resolve('www.google.com', 'HI'), /Unknown type/);
 
 // Try calling resolve with an unsupported type that's an object key
-assert.throws(function() {
-  dns.resolve('www.google.com', 'toString');
-}, /Unknown type/);
+assert.throws(() => dns.resolve('www.google.com', 'toString'), /Unknown type/);
 
 // Windows doesn't usually have an entry for localhost 127.0.0.1 in
 // C:\Windows\System32\drivers\etc\hosts