test: add test for url module domainToAscii and domainToUnicode

PR-URL: nodejs#10031
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-url-domain-ascii-unicode.js

@@ -0,0 +1,27 @@
+'use strict';
+
+require('../common');
+const strictEqual = require('assert').strictEqual;
+const url = require('url');
+
+const domainToASCII = url.URL.domainToASCII;
+const domainToUnicode = url.URL.domainToUnicode;
+
+const domainWithASCII = [
+  ['ıídيٴ', 'xn--d-iga7ro0q9f'],
+  ['www.ϧƽəʐ.com', 'www.xn--cja62apfr6c.com'],
+  ['новини.com', 'xn--b1amarcd.com'],
+  ['名がドメイン.com', 'xn--v8jxj3d1dzdz08w.com'],
+  ['افغانستا.icom.museum', 'xn--mgbaal8b0b9b2b.icom.museum'],
+  ['الجزائر.icom.fake', 'xn--lgbbat1ad8j.icom.fake'],
+  ['भारत.org', 'xn--h2brj9c.org']
+];
+
+domainWithASCII.forEach((pair) => {
+  const domain = pair[0];
+  const ascii = pair[1];
+  const domainConvertedToASCII = domainToASCII(domain);
+  strictEqual(domainConvertedToASCII, ascii);
+  const asciiConvertedToUnicode = domainToUnicode(ascii);
+  strictEqual(asciiConvertedToUnicode, domain);
+});