url: improve WHATWG URL inspection

PR-URL: https://github.com/nodejs/node/pull/12507
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/url.js

@@ -184,6 +184,17 @@ function onParseHashComplete(flags, protocol, username, password,
   }
 }
 
+function getEligibleConstructor(obj) {
+  while (obj !== null) {
+    if (Object.prototype.hasOwnProperty.call(obj, 'constructor') &&
+        typeof obj.constructor === 'function') {
+      return obj.constructor;
+    }
+    obj = Object.getPrototypeOf(obj);
+  }
+  return null;
+}
+
 class URL {
   constructor(input, base) {
     // toUSVString is not needed.
@@ -204,33 +215,43 @@ class URL {
   }
 
   [util.inspect.custom](depth, opts) {
+    if (this == null ||
+        Object.getPrototypeOf(this[context]) !== URLContext.prototype) {
+      throw new TypeError('Value of `this` is not a URL');
+    }
+
     const ctx = this[context];
-    var ret = 'URL {\n';
-    ret += `  href: ${this.href}\n`;
-    if (ctx.scheme !== undefined)
-      ret += `  protocol: ${this.protocol}\n`;
-    if (ctx.username !== undefined)
-      ret += `  username: ${this.username}\n`;
-    if (ctx.password !== undefined) {
-      const pwd = opts.showHidden ? ctx.password : '--------';
-      ret += `  password: ${pwd}\n`;
-    }
-    if (ctx.host !== undefined)
-      ret += `  hostname: ${this.hostname}\n`;
-    if (ctx.port !== undefined)
-      ret += `  port: ${this.port}\n`;
-    if (ctx.path !== undefined)
-      ret += `  pathname: ${this.pathname}\n`;
-    if (ctx.query !== undefined)
-      ret += `  search: ${this.search}\n`;
-    if (ctx.fragment !== undefined)
-      ret += `  hash: ${this.hash}\n`;
+
+    if (typeof depth === 'number' && depth < 0)
+      return opts.stylize('[Object]', 'special');
+
+    const ctor = getEligibleConstructor(this);
+
+    const obj = Object.create({
+      constructor: ctor === null ? URL : ctor
+    });
+
+    obj.href = this.href;
+    obj.origin = this.origin;
+    obj.protocol = this.protocol;
+    obj.username = this.username;
+    obj.password = (opts.showHidden || ctx.password == null) ?
+                     this.password : '--------';
+    obj.host = this.host;
+    obj.hostname = this.hostname;
+    obj.port = this.port;
+    obj.pathname = this.pathname;
+    obj.search = this.search;
+    obj.searchParams = this.searchParams;
+    obj.hash = this.hash;
+
     if (opts.showHidden) {
-      ret += `  cannot-be-base: ${this[cannotBeBase]}\n`;
-      ret += `  special: ${this[special]}\n`;
+      obj.cannotBeBase = this[cannotBeBase];
+      obj.special = this[special];
+      obj[context] = this[context];
     }
-    ret += '}';
-    return ret;
+
+    return util.inspect(obj, opts);
   }
 }
 
@@ -858,6 +879,9 @@ class URLSearchParams {
       throw new TypeError('Value of `this` is not a URLSearchParams');
     }
 
+    if (typeof recurseTimes === 'number' && recurseTimes < 0)
+      return ctx.stylize('[Object]', 'special');
+
     const separator = ', ';
     const innerOpts = Object.assign({}, ctx);
     if (recurseTimes !== null) {
@@ -1211,6 +1235,12 @@ defineIDLClass(URLSearchParamsIteratorPrototype, 'URLSearchParamsIterator', {
     };
   },
   [util.inspect.custom](recurseTimes, ctx) {
+    if (this == null || this[context] == null || this[context].target == null)
+      throw new TypeError('Value of `this` is not a URLSearchParamsIterator');
+
+    if (typeof recurseTimes === 'number' && recurseTimes < 0)
+      return ctx.stylize('[Object]', 'special');
+
     const innerOpts = Object.assign({}, ctx);
     if (recurseTimes !== null) {
       innerOpts.depth = recurseTimes - 1;

test/parallel/test-whatwg-url-inspect.js

@@ -3,7 +3,6 @@
 const common = require('../common');
 const util = require('util');
 const URL = require('url').URL;
-const path = require('path');
 const assert = require('assert');
 
 if (!common.hasIntl) {
@@ -13,71 +12,56 @@ if (!common.hasIntl) {
 }
 
 // Tests below are not from WPT.
-const tests = require(path.join(common.fixturesDir, 'url-tests'));
-const additional_tests = require(
-  path.join(common.fixturesDir, 'url-tests-additional'));
+const url = new URL('https://username:password@host.name:8080/path/name/?que=ry#hash');
 
-const allTests = additional_tests.slice();
-for (const test of tests) {
-  if (test.failure || typeof test === 'string') continue;
-  allTests.push(test);
-}
-
-for (const test of allTests) {
-  const url = test.url ? new URL(test.url) : new URL(test.input, test.base);
-
-  for (const showHidden of [true, false]) {
-    const res = util.inspect(url, {
-      showHidden
-    });
-
-    const lines = res.split('\n');
+assert.strictEqual(
+  util.inspect(url),
+  `URL {
+  href: 'https://username:password@host.name:8080/path/name/?que=ry#hash',
+  origin: 'https://host.name:8080',
+  protocol: 'https:',
+  username: 'username',
+  password: '--------',
+  host: 'host.name:8080',
+  hostname: 'host.name',
+  port: '8080',
+  pathname: '/path/name/',
+  search: '?que=ry',
+  searchParams: URLSearchParams { 'que' => 'ry' },
+  hash: '#hash' }`);
 
-    const firstLine = lines[0];
-    assert.strictEqual(firstLine, 'URL {');
+assert.strictEqual(
+  util.inspect(url, { showHidden: true }),
+  `URL {
+  href: 'https://username:password@host.name:8080/path/name/?que=ry#hash',
+  origin: 'https://host.name:8080',
+  protocol: 'https:',
+  username: 'username',
+  password: 'password',
+  host: 'host.name:8080',
+  hostname: 'host.name',
+  port: '8080',
+  pathname: '/path/name/',
+  search: '?que=ry',
+  searchParams: URLSearchParams { 'que' => 'ry' },
+  hash: '#hash',
+  cannotBeBase: false,
+  special: true,
+  [Symbol(context)]:\x20
+   URLContext {
+     flags: 2032,
+     scheme: 'https:',
+     username: 'username',
+     password: 'password',
+     host: 'host.name',
+     port: 8080,
+     path: [ 'path', 'name', '', [length]: 3 ],
+     query: 'que=ry',
+     fragment: 'hash' } }`);
 
-    const lastLine = lines[lines.length - 1];
-    assert.strictEqual(lastLine, '}');
+assert.strictEqual(
+  util.inspect({ a: url }, { depth: 0 }),
+  '{ a: [Object] }');
 
-    const innerLines = lines.slice(1, lines.length - 1);
-    const keys = new Set();
-    for (const line of innerLines) {
-      const i = line.indexOf(': ');
-      const k = line.slice(0, i).trim();
-      const v = line.slice(i + 2);
-      assert.strictEqual(keys.has(k), false, 'duplicate key found: ' + k);
-      keys.add(k);
-
-      const hidden = new Set([
-        'password',
-        'cannot-be-base',
-        'special'
-      ]);
-      if (showHidden) {
-        if (!hidden.has(k)) {
-          assert.strictEqual(v, url[k], k);
-          continue;
-        }
-
-        if (k === 'password') {
-          assert.strictEqual(v, url[k], k);
-        }
-        if (k === 'cannot-be-base') {
-          assert.ok(v.match(/^true$|^false$/), k + ' is Boolean');
-        }
-        if (k === 'special') {
-          assert.ok(v.match(/^true$|^false$/), k + ' is Boolean');
-        }
-        continue;
-      }
-
-      // showHidden is false
-      if (k === 'password') {
-        assert.strictEqual(v, '--------', k);
-        continue;
-      }
-      assert.strictEqual(hidden.has(k), false, 'no hidden keys: ' + k);
-      assert.strictEqual(v, url[k], k);
-    }
-  }
-}
+class MyURL extends URL {}
+assert(util.inspect(new MyURL(url.href)).startsWith('MyURL {'));