Implement ownProperty() and inheritFrom() assertions in should()

third_party/WebKit/LayoutTests/webaudio/resources/audit.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 /**
  * @fileOverview  WebAudio layout test utility library. Built around W3C's
  *                testharness.js. Includes asynchronous test task manager,
  *                assertion utilities.
  * @dependency    testharness.js
@@ skipping 946 matching lines @@
      *   should(true, 'The message is').message('truthful!', 'false!');
      *
      * @result
      *   "PASS   The message is truthful!"
      */
     message(passDetail, failDetail) {
       return this._assert(this._actual,
                           '${actual} ' + passDetail,
                           '${actual} ' + failDetail);
     }
+
+    /**
+     * Check if |expected| property is truly owned by |actual| object.
+     *
+     * @example
+     *   should(BaseAudioContext.prototype,
+     *          'BaseAudioContext.prototype').ownProperty('createGain');
+     *
+     * @result
+     *   "PASS   BaseAudioContext.prototype has an own property of
+     *       'createGain'."
+     */
+    ownProperty() {

[Raymond Toy, 2017/04/06 23:13:14]

ownProperty or beOwnPropertyOf (as mentioned in the bug)?

[hongchan, 2017/04/07 15:55:36]

I think this is cleaner. Let me know if you think otherwise. (You're the primary
customer!)

[Raymond Toy, 2017/04/07 16:10:58]

Maybe

should(obj).haveOwnProperty(property)

?  beOwnPropertyOf is backwards.

[hongchan, 2017/04/07 17:22:16]

I llke haveOwnProperty().

+      this._processArguments(arguments);
+
+      return this._assert(
+          this._actual.hasOwnProperty(this._expected),
+          '${actual} has an own property of "${expected}".',
+          '${actual} does not own the property of "${expected}".');
+    }
+
+
+    /**
+     * Check if an object is inherited from a class. This looks up the entire
+     * prototype chain of a given object and tries to find a match.
+     *
+     * @example
+     *   should(sourceNode, 'A buffer source node')
+     *       .inheritFrom('AudioScheduledSourceNode');
+     *
+     * @result
+     *   "PASS   A buffer source node inherits from 'AudioScheduledSourceNode'."
+     */
+    inheritFrom() {
+      this._processArguments(arguments);
+
+      let prototypes = [];
+      let currentPrototype = Object.getPrototypeOf(this._actual);
+      while (currentPrototype) {
+        prototypes.push(currentPrototype.constructor.name);
+        currentPrototype = Object.getPrototypeOf(currentPrototype);
+      }
+
+      return this._assert(
+          prototypes.includes(this._expected),
+          '${actual} inherits from "${expected}".',
+          '${actual} does not inherit from "${expected}".');
+    }
   }
 
 
   // Task Class state enum.
   const TaskState = {
     PENDING: 0,
     STARTED: 1,
     FINISHED: 2
   };
 
@@ skipping 292 matching lines @@
 
     /**
      * Load file from a given URL and pass ArrayBuffer to the following promise.
      * See |loadFileFromUrl| method for the detail.
      */
     loadFileFromUrl: loadFileFromUrl
 
   };
 
 })();