diff --git a/test/parallel/test-punycode.js b/test/parallel/test-punycode.js
index abd495e4a9957b..e869e6a33bf064 100644
--- a/test/parallel/test-punycode.js
+++ b/test/parallel/test-punycode.js
@@ -1,153 +1,224 @@
 'use strict';
 require('../common');
-var punycode = require('punycode');
-var assert = require('assert');
+const punycode = require('punycode');
+const assert = require('assert');
 
-assert.equal(punycode.encode('ü'), 'tda');
-assert.equal(punycode.encode('Goethe'), 'Goethe-');
-assert.equal(punycode.encode('Bücher'), 'Bcher-kva');
-assert.equal(punycode.encode(
+assert.strictEqual(punycode.encode('ü'), 'tda');
+assert.strictEqual(punycode.encode('Goethe'), 'Goethe-');
+assert.strictEqual(punycode.encode('Bücher'), 'Bcher-kva');
+assert.strictEqual(punycode.encode(
     'Willst du die Blüthe des frühen, die Früchte des späteren Jahres'),
     'Willst du die Blthe des frhen, die Frchte des spteren Jahres-x9e96lkal');
-assert.equal(punycode.encode('日本語'), 'wgv71a119e');
+assert.strictEqual(punycode.encode('日本語'), 'wgv71a119e');
 
-assert.equal(punycode.decode('tda'), 'ü');
-assert.equal(punycode.decode('Goethe-'), 'Goethe');
-assert.equal(punycode.decode('Bcher-kva'), 'Bücher');
-assert.equal(punycode.decode(
+assert.strictEqual(punycode.decode('tda'), 'ü');
+assert.strictEqual(punycode.decode('Goethe-'), 'Goethe');
+assert.strictEqual(punycode.decode('Bcher-kva'), 'Bücher');
+assert.strictEqual(punycode.decode(
     'Willst du die Blthe des frhen, die Frchte des spteren Jahres-x9e96lkal'),
     'Willst du die Blüthe des frühen, die Früchte des späteren Jahres');
-assert.equal(punycode.decode('wgv71a119e'), '日本語');
+assert.strictEqual(punycode.decode('wgv71a119e'), '日本語');
 
 // http://tools.ietf.org/html/rfc3492#section-7.1
-var tests = {
+const tests = [
   // (A) Arabic (Egyptian)
-  'egbpdaj6bu4bxfgehfvwxn':
-      '\u0644\u064A\u0647\u0645\u0627\u0628\u062A\u0643\u0644\u0645\u0648' +
-      '\u0634\u0639\u0631\u0628\u064A\u061F',
+  {
+    encoded: 'egbpdaj6bu4bxfgehfvwxn',
+    decoded: '\u0644\u064A\u0647\u0645\u0627\u0628\u062A\u0643\u0644\u0645' +
+      '\u0648\u0634\u0639\u0631\u0628\u064A\u061F'
+  },
 
   // (B) Chinese (simplified)
-  'ihqwcrb4cv8a8dqg056pqjye':
-      '\u4ED6\u4EEC\u4E3A\u4EC0\u4E48\u4E0D\u8BF4\u4E2D\u6587',
+  {
+    encoded: 'ihqwcrb4cv8a8dqg056pqjye',
+    decoded: '\u4ED6\u4EEC\u4E3A\u4EC0\u4E48\u4E0D\u8BF4\u4E2D\u6587'
+  },
 
   // (C) Chinese (traditional)
-  'ihqwctvzc91f659drss3x8bo0yb':
-      '\u4ED6\u5011\u7232\u4EC0\u9EBD\u4E0D\u8AAA\u4E2D\u6587',
+  {
+    encoded: 'ihqwctvzc91f659drss3x8bo0yb',
+    decoded: '\u4ED6\u5011\u7232\u4EC0\u9EBD\u4E0D\u8AAA\u4E2D\u6587'
+  },
 
   // (D) Czech: Pro<ccaron>prost<ecaron>nemluv<iacute><ccaron>esky
-  'Proprostnemluvesky-uyb24dma41a':
-      '\u0050\u0072\u006F\u010D\u0070\u0072\u006F\u0073\u0074\u011B\u006E' +
-      '\u0065\u006D\u006C\u0075\u0076\u00ED\u010D\u0065\u0073\u006B\u0079',
+  {
+    encoded: 'Proprostnemluvesky-uyb24dma41a',
+    decoded: '\u0050\u0072\u006F\u010D\u0070\u0072\u006F\u0073\u0074\u011B' +
+      '\u006E\u0065\u006D\u006C\u0075\u0076\u00ED\u010D\u0065\u0073\u006B\u0079'
+  },
 
   // (E) Hebrew
-  '4dbcagdahymbxekheh6e0a7fei0b':
-      '\u05DC\u05DE\u05D4\u05D4\u05DD\u05E4\u05E9\u05D5\u05D8\u05DC\u05D0' +
-      '\u05DE\u05D3\u05D1\u05E8\u05D9\u05DD\u05E2\u05D1\u05E8\u05D9\u05EA',
+  {
+    encoded: '4dbcagdahymbxekheh6e0a7fei0b',
+    decoded: '\u05DC\u05DE\u05D4\u05D4\u05DD\u05E4\u05E9\u05D5\u05D8\u05DC' +
+      '\u05D0\u05DE\u05D3\u05D1\u05E8\u05D9\u05DD\u05E2\u05D1\u05E8\u05D9\u05EA'
+  },
 
   // (F) Hindi (Devanagari)
-  'i1baa7eci9glrd9b2ae1bj0hfcgg6iyaf8o0a1dig0cd':
-      '\u092F\u0939\u0932\u094B\u0917\u0939\u093F\u0928\u094D\u0926\u0940' +
-      '\u0915\u094D\u092F\u094B\u0902\u0928\u0939\u0940\u0902\u092C\u094B' +
-      '\u0932\u0938\u0915\u0924\u0947\u0939\u0948\u0902',
+  {
+    encoded: 'i1baa7eci9glrd9b2ae1bj0hfcgg6iyaf8o0a1dig0cd',
+    decoded: '\u092F\u0939\u0932\u094B\u0917\u0939\u093F\u0928\u094D\u0926' +
+      '\u0940\u0915\u094D\u092F\u094B\u0902\u0928\u0939\u0940\u0902\u092C' +
+      '\u094B\u0932\u0938\u0915\u0924\u0947\u0939\u0948\u0902'
+  },
 
   // (G) Japanese (kanji and hiragana)
-  'n8jok5ay5dzabd5bym9f0cm5685rrjetr6pdxa':
-      '\u306A\u305C\u307F\u3093\u306A\u65E5\u672C\u8A9E\u3092\u8A71\u3057' +
-      '\u3066\u304F\u308C\u306A\u3044\u306E\u304B',
+  {
+    encoded: 'n8jok5ay5dzabd5bym9f0cm5685rrjetr6pdxa',
+    decoded: '\u306A\u305C\u307F\u3093\u306A\u65E5\u672C\u8A9E\u3092\u8A71' +
+      '\u3057\u3066\u304F\u308C\u306A\u3044\u306E\u304B'
+  },
 
   // (H) Korean (Hangul syllables)
-  '989aomsvi5e83db1d2a355cv1e0vak1dwrv93d5xbh15a0dt30a5jpsd879ccm6fea98c':
-      '\uC138\uACC4\uC758\uBAA8\uB4E0\uC0AC\uB78C\uB4E4\uC774\uD55C\uAD6D' +
-      '\uC5B4\uB97C\uC774\uD574\uD55C\uB2E4\uBA74\uC5BC\uB9C8\uB098\uC88B' +
-      '\uC744\uAE4C',
+  {
+    encoded: '989aomsvi5e83db1d2a355cv1e0vak1dwrv93d5xbh15a0dt30a5jpsd879' +
+      'ccm6fea98c',
+    decoded: '\uC138\uACC4\uC758\uBAA8\uB4E0\uC0AC\uB78C\uB4E4\uC774\uD55C' +
+      '\uAD6D\uC5B4\uB97C\uC774\uD574\uD55C\uB2E4\uBA74\uC5BC\uB9C8\uB098' +
+      '\uC88B\uC744\uAE4C'
+  },
 
   // (I) Russian (Cyrillic)
-  'b1abfaaepdrnnbgefbadotcwatmq2g4l':
-      '\u043F\u043E\u0447\u0435\u043C\u0443\u0436\u0435\u043E\u043D\u0438' +
-      '\u043D\u0435\u0433\u043E\u0432\u043E\u0440\u044F\u0442\u043F\u043E' +
-      '\u0440\u0443\u0441\u0441\u043A\u0438',
+  {
+    encoded: 'b1abfaaepdrnnbgefbadotcwatmq2g4l',
+    decoded: '\u043F\u043E\u0447\u0435\u043C\u0443\u0436\u0435\u043E\u043D' +
+      '\u0438\u043D\u0435\u0433\u043E\u0432\u043E\u0440\u044F\u0442\u043F' +
+      '\u043E\u0440\u0443\u0441\u0441\u043A\u0438'
+  },
 
   // (J) Spanish: Porqu<eacute>nopuedensimplementehablarenEspa<ntilde>ol
-  'PorqunopuedensimplementehablarenEspaol-fmd56a':
-      '\u0050\u006F\u0072\u0071\u0075\u00E9\u006E\u006F\u0070\u0075\u0065' +
-      '\u0064\u0065\u006E\u0073\u0069\u006D\u0070\u006C\u0065\u006D\u0065' +
-      '\u006E\u0074\u0065\u0068\u0061\u0062\u006C\u0061\u0072\u0065\u006E' +
-      '\u0045\u0073\u0070\u0061\u00F1\u006F\u006C',
+  {
+    encoded: 'PorqunopuedensimplementehablarenEspaol-fmd56a',
+    decoded: '\u0050\u006F\u0072\u0071\u0075\u00E9\u006E\u006F\u0070\u0075' +
+      '\u0065\u0064\u0065\u006E\u0073\u0069\u006D\u0070\u006C\u0065\u006D' +
+      '\u0065\u006E\u0074\u0065\u0068\u0061\u0062\u006C\u0061\u0072\u0065' +
+      '\u006E\u0045\u0073\u0070\u0061\u00F1\u006F\u006C'
+  },
 
   // (K) Vietnamese: T<adotbelow>isaoh<odotbelow>kh<ocirc>ngth
   // <ecirchookabove>ch<ihookabove>n<oacute>iti<ecircacute>ngVi<ecircdotbelow>t
-  'TisaohkhngthchnitingVit-kjcr8268qyxafd2f1b9g':
-      '\u0054\u1EA1\u0069\u0073\u0061\u006F\u0068\u1ECD\u006B\u0068\u00F4' +
-      '\u006E\u0067\u0074\u0068\u1EC3\u0063\u0068\u1EC9\u006E\u00F3\u0069' +
-      '\u0074\u0069\u1EBF\u006E\u0067\u0056\u0069\u1EC7\u0074',
+  {
+    encoded: 'TisaohkhngthchnitingVit-kjcr8268qyxafd2f1b9g',
+    decoded: '\u0054\u1EA1\u0069\u0073\u0061\u006F\u0068\u1ECD\u006B\u0068' +
+      '\u00F4\u006E\u0067\u0074\u0068\u1EC3\u0063\u0068\u1EC9\u006E\u00F3' +
+      '\u0069\u0074\u0069\u1EBF\u006E\u0067\u0056\u0069\u1EC7\u0074'
+  },
 
   // (L) 3<nen>B<gumi><kinpachi><sensei>
-  '3B-ww4c5e180e575a65lsy2b':
-      '\u0033\u5E74\u0042\u7D44\u91D1\u516B\u5148\u751F',
+  {
+    encoded: '3B-ww4c5e180e575a65lsy2b',
+    decoded: '\u0033\u5E74\u0042\u7D44\u91D1\u516B\u5148\u751F'
+  },
 
   // (M) <amuro><namie>-with-SUPER-MONKEYS
-  '-with-SUPER-MONKEYS-pc58ag80a8qai00g7n9n':
-      '\u5B89\u5BA4\u5948\u7F8E\u6075\u002D\u0077\u0069\u0074\u0068\u002D' +
-      '\u0053\u0055\u0050\u0045\u0052\u002D\u004D\u004F\u004E\u004B\u0045' +
-      '\u0059\u0053',
+  {
+    encoded: '-with-SUPER-MONKEYS-pc58ag80a8qai00g7n9n',
+    decoded: '\u5B89\u5BA4\u5948\u7F8E\u6075\u002D\u0077\u0069\u0074\u0068' +
+      '\u002D\u0053\u0055\u0050\u0045\u0052\u002D\u004D\u004F\u004E\u004B' +
+      '\u0045\u0059\u0053'
+  },
 
   // (N) Hello-Another-Way-<sorezore><no><basho>
-  'Hello-Another-Way--fc4qua05auwb3674vfr0b':
-      '\u0048\u0065\u006C\u006C\u006F\u002D\u0041\u006E\u006F\u0074\u0068' +
-      '\u0065\u0072\u002D\u0057\u0061\u0079\u002D\u305D\u308C\u305E\u308C' +
-      '\u306E\u5834\u6240',
+  {
+    encoded: 'Hello-Another-Way--fc4qua05auwb3674vfr0b',
+    decoded: '\u0048\u0065\u006C\u006C\u006F\u002D\u0041\u006E\u006F\u0074' +
+      '\u0068\u0065\u0072\u002D\u0057\u0061\u0079\u002D\u305D\u308C\u305E' +
+      '\u308C\u306E\u5834\u6240'
+  },
 
   // (O) <hitotsu><yane><no><shita>2
-  '2-u9tlzr9756bt3uc0v':
-      '\u3072\u3068\u3064\u5C4B\u6839\u306E\u4E0B\u0032',
+  {
+    encoded: '2-u9tlzr9756bt3uc0v',
+    decoded: '\u3072\u3068\u3064\u5C4B\u6839\u306E\u4E0B\u0032'
+  },
 
   // (P) Maji<de>Koi<suru>5<byou><mae>
-  'MajiKoi5-783gue6qz075azm5e':
-      '\u004D\u0061\u006A\u0069\u3067\u004B\u006F\u0069\u3059\u308B\u0035' +
-      '\u79D2\u524D',
+  {
+    encoded: 'MajiKoi5-783gue6qz075azm5e',
+    decoded: '\u004D\u0061\u006A\u0069\u3067\u004B\u006F\u0069\u3059\u308B' +
+      '\u0035\u79D2\u524D'
+  },
 
   // (Q) <pafii>de<runba>
-  'de-jg4avhby1noc0d':
-      '\u30D1\u30D5\u30A3\u30FC\u0064\u0065\u30EB\u30F3\u30D0',
+  {
+    encoded: 'de-jg4avhby1noc0d',
+    decoded: '\u30D1\u30D5\u30A3\u30FC\u0064\u0065\u30EB\u30F3\u30D0'
+  },
 
   // (R) <sono><supiido><de>
-  'd9juau41awczczp':
-      '\u305D\u306E\u30B9\u30D4\u30FC\u30C9\u3067',
+  {
+    encoded: 'd9juau41awczczp',
+    decoded: '\u305D\u306E\u30B9\u30D4\u30FC\u30C9\u3067'
+  },
 
   // (S) -> $1.00 <-
-  '-> $1.00 <--':
-      '\u002D\u003E\u0020\u0024\u0031\u002E\u0030\u0030\u0020\u003C\u002D'
+  {
+    encoded: '-> $1.00 <--',
+    decoded: '\u002D\u003E\u0020\u0024\u0031\u002E\u0030\u0030\u0020\u003C' +
+      '\u002D'
+  }
+];
+
+let errors = 0;
+const handleError = (error, name) => {
+  console.error(
+    'FAIL: %s expected %j, got %j',
+    name,
+    error.expected,
+    error.actual
+  );
+  errors++;
 };
 
-var errors = 0;
+const regexNonASCII = /[^\x20-\x7E]/;
+const testBattery = {
+  encode: (test) => assert.strictEqual(
+    punycode.encode(test.decoded),
+    test.encoded
+  ),
+  decode: (test) => assert.strictEqual(
+    punycode.decode(test.encoded),
+    test.decoded
+  ),
+  toASCII: (test) => assert.strictEqual(
+    punycode.toASCII(test.decoded),
+    regexNonASCII.test(test.decoded)
+      ? `xn--${test.encoded}`
+      : test.decoded
+  ),
+  toUnicode: (test) => assert.strictEqual(
+    punycode.toUnicode(
+      regexNonASCII.test(test.decoded)
+        ? `xn--${test.encoded}`
+        : test.decoded
+    ),
+    regexNonASCII.test(test.decoded)
+      ? test.decoded.toLowerCase()
+      : test.decoded
+  )
+};
 
-for (var encoded in tests) {
-  var decoded = tests[encoded];
-  try {
-    assert.equal(punycode.encode(decoded), encoded);
-  } catch (e) {
-    console.error('FAIL: expected %j, got %j', e.expected, e.actual);
-    errors++;
-  }
-  try {
-    assert.equal(punycode.decode(encoded), decoded);
-  } catch (e) {
-    console.error('FAIL: expected %j, got %j', e.expected, e.actual);
-    errors++;
-  }
-}
+tests.forEach((testCase) => {
+  Object.keys(testBattery).forEach((key) => {
+    try {
+      testBattery[key](testCase);
+    } catch (error) {
+      handleError(error, key);
+    }
+  });
+});
 
 // BMP code point
-assert.equal(punycode.ucs2.encode([0x61]), 'a');
+assert.strictEqual(punycode.ucs2.encode([0x61]), 'a');
 // supplementary code point (surrogate pair)
-assert.equal(punycode.ucs2.encode([0x1D306]), '\uD834\uDF06');
+assert.strictEqual(punycode.ucs2.encode([0x1D306]), '\uD834\uDF06');
 // high surrogate
-assert.equal(punycode.ucs2.encode([0xD800]), '\uD800');
+assert.strictEqual(punycode.ucs2.encode([0xD800]), '\uD800');
 // high surrogate followed by non-surrogates
-assert.equal(punycode.ucs2.encode([0xD800, 0x61, 0x62]), '\uD800ab');
+assert.strictEqual(punycode.ucs2.encode([0xD800, 0x61, 0x62]), '\uD800ab');
 // low surrogate
-assert.equal(punycode.ucs2.encode([0xDC00]), '\uDC00');
+assert.strictEqual(punycode.ucs2.encode([0xDC00]), '\uDC00');
 // low surrogate followed by non-surrogates
-assert.equal(punycode.ucs2.encode([0xDC00, 0x61, 0x62]), '\uDC00ab');
+assert.strictEqual(punycode.ucs2.encode([0xDC00, 0x61, 0x62]), '\uDC00ab');
 
-assert.equal(errors, 0);
+assert.strictEqual(errors, 0);