url: do not public expose inspect methods on URL

PR-URL: https://github.com/nodejs/node/pull/10906
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

lib/internal/url.js

@@ -77,7 +77,7 @@ class TupleOrigin {
     return result;
   }
 
-  inspect() {
+  [util.inspect.custom]() {
     return `TupleOrigin {
       scheme: ${this[kScheme]},
       host: ${this[kHost]},
@@ -235,7 +235,7 @@ class URL {
     return (this[context].flags & binding.URL_FLAGS_CANNOT_BE_BASE) !== 0;
   }
 
-  inspect(depth, opts) {
+  [util.inspect.custom](depth, opts) {
     const ctx = this[context];
     var ret = 'URL {\n';
     ret += `  href: ${this.href}\n`;

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

@@ -1,6 +1,7 @@
 'use strict';
 
 const common = require('../common');
+const util = require('util');
 
 if (!common.hasIntl) {
   // A handful of the tests fail when ICU is not included.
@@ -144,8 +145,8 @@ 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 = url.inspect(null, {
-      showHidden: showHidden
+    const res = util.inspect(url, {
+      showHidden
     });
 
     const lines = res.split('\n');