url: move to module.exports = {} pattern

PR-URL: #12717
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com

lib/url.js

@@ -23,19 +23,19 @@
 
 const { toASCII } = process.binding('config').hasIntl ?
   process.binding('icu') : require('punycode');
+
 const { hexTable } = require('internal/querystring');
-const internalUrl = require('internal/url');
-exports.parse = urlParse;
-exports.resolve = urlResolve;
-exports.resolveObject = urlResolveObject;
-exports.format = urlFormat;
-exports.URL = internalUrl.URL;
-exports.URLSearchParams = internalUrl.URLSearchParams;
-exports.domainToASCII = internalUrl.domainToASCII;
-exports.domainToUnicode = internalUrl.domainToUnicode;
 
+// WHATWG URL implementation provided by internal/url
+const {
+  URL,
+  URLSearchParams,
+  domainToASCII,
+  domainToUnicode,
+  formatSymbol
+} = require('internal/url');
 
-exports.Url = Url;
+// Original url.parse() API
 
 function Url() {
   this.protocol = null;
@@ -559,7 +559,7 @@ function urlFormat(obj, options) {
     throw new TypeError('Parameter "urlObj" must be an object, not ' +
                         (obj === null ? 'null' : typeof obj));
   } else if (!(obj instanceof Url)) {
-    var format = obj[internalUrl.formatSymbol];
+    var format = obj[formatSymbol];
     return format ?
       format.call(obj, options) :
       Url.prototype.format.call(obj);
@@ -1030,3 +1030,18 @@ function encodeAuth(str) {
     return out + str.slice(lastPos);
   return out;
 }
+
+module.exports = {
+  // Original API
+  Url,
+  parse: urlParse,
+  resolve: urlResolve,
+  resolveObject: urlResolveObject,
+  format: urlFormat,
+
+  // WHATWG API
+  URL,
+  URLSearchParams,
+  domainToASCII,
+  domainToUnicode
+};