url: improve WHATWG URL inspection

PR-URL: https://github.com/nodejs/node/pull/12253
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 54 insertions, 24 deletions

diff --git a/lib/internal/url.js b/lib/internal/url.js
index 629bbb2ece..771a916d70 100644
--- a/lib/internal/url.js
+++ b/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;