url: clean up WHATWG URL origin generation

- Use ordinary properties instead of symbols/getter redirection for
  internal object
- Use template string literals
- Remove unneeded custom inspection for internal objects
- Remove unneeded OpaqueOrigin class
- Remove unneeded type checks

PR-URL: #12507
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/url.js

@@ -15,10 +15,6 @@ const os = require('os');
 
 const isWindows = process.platform === 'win32';
 
-const kScheme = Symbol('scheme');
-const kHost = Symbol('host');
-const kPort = Symbol('port');
-const kDomain = Symbol('domain');
 const kFormat = Symbol('format');
 
 // https://tc39.github.io/ecma262/#sec-%iteratorprototype%-object
@@ -38,62 +34,15 @@ function toUSVString(val) {
   return binding.toUSVString(str, match.index);
 }
 
-class OpaqueOrigin {
-  toString() {
-    return 'null';
-  }
+// Refs: https://html.spec.whatwg.org/multipage/browsers.html#concept-origin-opaque
+const kOpaqueOrigin = 'null';
 
-  get effectiveDomain() {
-    return this;
-  }
-}
-
-class TupleOrigin {
-  constructor(scheme, host, port, domain) {
-    this[kScheme] = scheme;
-    this[kHost] = host;
-    this[kPort] = port;
-    this[kDomain] = domain;
-  }
-
-  get scheme() {
-    return this[kScheme];
-  }
-
-  get host() {
-    return this[kHost];
-  }
-
-  get port() {
-    return this[kPort];
-  }
-
-  get domain() {
-    return this[kDomain];
-  }
-
-  get effectiveDomain() {
-    return this[kDomain] || this[kHost];
-  }
-
-  // https://url.spec.whatwg.org/#dom-url-origin
-  toString(unicode = true) {
-    var result = this[kScheme];
-    result += '://';
-    result += unicode ? domainToUnicode(this[kHost]) : this[kHost];
-    if (this[kPort] !== undefined && this[kPort] !== null)
-      result += `:${this[kPort]}`;
-    return result;
-  }
-
-  [util.inspect.custom]() {
-    return `TupleOrigin {
-      scheme: ${this[kScheme]},
-      host: ${this[kHost]},
-      port: ${this[kPort]},
-      domain: ${this[kDomain]}
-    }`;
-  }
+// Refs:
+// - https://html.spec.whatwg.org/multipage/browsers.html#unicode-serialisation-of-an-origin
+// - https://html.spec.whatwg.org/multipage/browsers.html#ascii-serialisation-of-an-origin
+function serializeTupleOrigin(scheme, host, port, unicode = true) {
+  const unicodeHost = unicode ? domainToUnicode(host) : host;
+  return `${scheme}//${unicodeHost}${port == null ? '' : `:${port}`}`;
 }
 
 // This class provides the internal state of a URL object. An instance of this
@@ -359,7 +308,27 @@ Object.defineProperties(URL.prototype, {
     enumerable: true,
     configurable: true,
     get() {
-      return originFor(this).toString();
+      // Refs: https://url.spec.whatwg.org/#concept-url-origin
+      const ctx = this[context];
+      switch (ctx.scheme) {
+        case 'blob:':
+          if (ctx.path.length > 0) {
+            try {
+              return (new URL(ctx.path[0])).origin;
+            } catch (err) {
+              // fall through... do nothing
+            }
+          }
+          return kOpaqueOrigin;
+        case 'ftp:':
+        case 'gopher:':
+        case 'http:':
+        case 'https:':
+        case 'ws:':
+        case 'wss:':
+          return serializeTupleOrigin(ctx.scheme, ctx.host, ctx.port);
+      }
+      return kOpaqueOrigin;
     }
   },
   protocol: {
@@ -1274,41 +1243,6 @@ defineIDLClass(URLSearchParamsIteratorPrototype, 'URLSearchParamsIterator', {
   }
 });
 
-function originFor(url, base) {
-  if (url != undefined &&
-      (!url[searchParams] || !url[searchParams][searchParams])) {
-    url = new URL(url, base);
-  }
-  var origin;
-  const protocol = url.protocol;
-  switch (protocol) {
-    case 'blob:':
-      if (url[context].path && url[context].path.length > 0) {
-        try {
-          return (new URL(url[context].path[0])).origin;
-        } catch (err) {
-          // fall through... do nothing
-        }
-      }
-      origin = new OpaqueOrigin();
-      break;
-    case 'ftp:':
-    case 'gopher:':
-    case 'http:':
-    case 'https:':
-    case 'ws:':
-    case 'wss:':
-      origin = new TupleOrigin(protocol.slice(0, -1),
-                               url[context].host,
-                               url[context].port,
-                               null);
-      break;
-    default:
-      origin = new OpaqueOrigin();
-  }
-  return origin;
-}
-
 function domainToASCII(domain) {
   if (arguments.length < 1)
     throw new TypeError('"domain" argument must be specified');