fix(node/util): fix util.inherits

node/_tools/config.json

@@ -17,7 +17,8 @@
       "test-event-emitter-invalid-listener.js",
       "test-event-emitter-listener-count.js",
       "test-event-emitter-listeners.js",
-      "test-event-emitter-once.js"
+      "test-event-emitter-once.js",
+      "test-util-inherits.js"
     ]
   },
   "suitesFolder": "suites",

node/_tools/suites/parallel/test-util-inherits.js

@@ -0,0 +1,117 @@
+// deno-fmt-ignore-file
+// deno-lint-ignore-file
+
+// Copyright Joyent and Node contributors. All rights reserved. MIT license.
+// Taken from Node 15.5.1
+// This file is automatically generated by "node/_tools/setup.ts". Do not modify this file manually
+
+'use strict';
+
+require('../common');
+const assert = require('assert');
+const { inherits } = require('util');
+
+// Super constructor
+function A() {
+  this._a = 'a';
+}
+A.prototype.a = function() { return this._a; };
+
+// One level of inheritance
+function B(value) {
+  A.call(this);
+  this._b = value;
+}
+inherits(B, A);
+B.prototype.b = function() { return this._b; };
+
+assert.deepStrictEqual(
+  Object.getOwnPropertyDescriptor(B, 'super_'),
+  {
+    value: A,
+    enumerable: false,
+    configurable: true,
+    writable: true
+  }
+);
+
+const b = new B('b');
+assert.strictEqual(b.a(), 'a');
+assert.strictEqual(b.b(), 'b');
+assert.strictEqual(b.constructor, B);
+
+// Two levels of inheritance
+function C() {
+  B.call(this, 'b');
+  this._c = 'c';
+}
+inherits(C, B);
+C.prototype.c = function() { return this._c; };
+C.prototype.getValue = function() { return this.a() + this.b() + this.c(); };
+
+assert.strictEqual(C.super_, B);
+
+const c = new C();
+assert.strictEqual(c.getValue(), 'abc');
+assert.strictEqual(c.constructor, C);
+
+// Inherits can be called after setting prototype properties
+function D() {
+  C.call(this);
+  this._d = 'd';
+}
+
+D.prototype.d = function() { return this._d; };
+inherits(D, C);
+
+assert.strictEqual(D.super_, C);
+
+const d = new D();
+assert.strictEqual(d.c(), 'c');
+assert.strictEqual(d.d(), 'd');
+assert.strictEqual(d.constructor, D);
+
+// ES6 classes can inherit from a constructor function
+class E {
+  constructor() {
+    D.call(this);
+    this._e = 'e';
+  }
+  e() { return this._e; }
+}
+inherits(E, D);
+
+assert.strictEqual(E.super_, D);
+
+const e = new E();
+assert.strictEqual(e.getValue(), 'abc');
+assert.strictEqual(e.d(), 'd');
+assert.strictEqual(e.e(), 'e');
+assert.strictEqual(e.constructor, E);
+
+// Should throw with invalid arguments
+assert.throws(() => {
+  inherits(A, {});
+}, {
+  code: 'ERR_INVALID_ARG_TYPE',
+  name: 'TypeError',
+  message: 'The "superCtor.prototype" property must be of type object. ' +
+           'Received undefined'
+});
+
+assert.throws(() => {
+  inherits(A, null);
+}, {
+  code: 'ERR_INVALID_ARG_TYPE',
+  name: 'TypeError',
+  message: 'The "superCtor" argument must be of type function. ' +
+           'Received null'
+});
+
+assert.throws(() => {
+  inherits(null, A);
+}, {
+  code: 'ERR_INVALID_ARG_TYPE',
+  name: 'TypeError',
+  message: 'The "ctor" argument must be of type function. Received null'
+});

node/util.ts

@@ -294,7 +294,7 @@ export function inherits<T, U>(
     writable: true,
     configurable: true,
   });
-  Object.setPrototypeOf(ctor, superCtor.prototype);
+  Object.setPrototypeOf(ctor.prototype, superCtor.prototype);
 }
 
 import { _TextDecoder, _TextEncoder } from "./_utils.ts";

node/util_test.ts

@@ -302,16 +302,3 @@ Deno.test("[util] format", () => {
     `${expected} ${expected} 10`,
   );
 });
-
-Deno.test("[util] inherits", () => {
-  class Ctor {
-  }
-
-  class SuperCtor {
-    superMethod() {}
-  }
-
-  util.inherits(Ctor, SuperCtor);
-
-  assert(Object.getPrototypeOf(Ctor).hasOwnProperty("superMethod"));
-});