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

This CL add two assertions that abstracts the checks for JavaScript
traits.

 - should().ownProperty()
 - should().inheritFrom()

BUG=702708
TEST=webaudio/unit-tests/audit.html

Review-Url: https://codereview.chromium.org/2805773002
Cr-Commit-Position: refs/heads/master@{#462970}

third_party/WebKit/LayoutTests/webaudio/audio-scheduled-source-basic.html

@@ -36,22 +36,17 @@
 
             // AudioScheduledSourceNode must have these properties.
             for (p in expectedProperties) {
-              should(
-                  AudioScheduledSourceNode.prototype.hasOwnProperty(
-                      expectedProperties[p]),
-                  'AudioScheduledSourceNode.' + expectedProperties[p])
-                  .beTrue();
+              should(AudioScheduledSourceNode.prototype,
+                     'AudioScheduledSourceNode.prototype')
+                  .haveOwnProperty(expectedProperties[p]);
             }
 
             // ConstantSource and Oscillator must not
             var nodes = ['ConstantSourceNode', 'OscillatorNode'];
             for (n in nodes) {
               for (p in expectedProperties) {
-                should(
-                    window[nodes[n]].prototype.hasOwnProperty(
-                        expectedProperties[p]),
-                    nodes[n] + '.' + expectedProperties[p])
-                    .beFalse();
+                should(window[nodes[n]].prototype, nodes[n] + '.prototype')
+                    .notHaveOwnProperty(expectedProperties[p]);
               }
             }
 
@@ -59,18 +54,15 @@
             // have the others.
             for (p in expectedProperties) {
               if (expectedProperties[p] !== 'start') {
-                should(
-                    AudioBufferSourceNode.prototype.hasOwnProperty(
-                        expectedProperties[p]),
-                    'AudioBufferSourceNode.' + expectedProperties[p])
-                    .beFalse();
+                should(AudioBufferSourceNode.prototype,
+                       'AudioBufferSourceNode.prototype')
+                    .notHaveOwnProperty(expectedProperties[p]);
               }
             }
 
-            should(
-                AudioBufferSourceNode.prototype.hasOwnProperty('start'),
-                'AudioBufferSourceNode.start')
-                .beTrue();
+            should(AudioBufferSourceNode.prototype,
+                   'AudioBufferSourceNode.prototype')
+                .haveOwnProperty('start');
 
             task.done();
           });

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

@@ -977,6 +977,76 @@ window.Audit = (function () {
                           '${actual} ' + passDetail,
                           '${actual} ' + failDetail);
     }
+
+    /**
+     * Check if |expected| property is truly owned by |actual| object.
+     *
+     * @example
+     *   should(BaseAudioContext.prototype,
+     *          'BaseAudioContext.prototype').haveOwnProperty('createGain');
+     *
+     * @result
+     *   "PASS   BaseAudioContext.prototype has an own property of
+     *       'createGain'."
+     */
+    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 |expected| property is not owned by |actual| object.
+     *
+     * @example
+     *   should(BaseAudioContext.prototype,
+     *          'BaseAudioContext.prototype')
+     *       .notHaveOwnProperty('startRendering');
+     *
+     * @result
+     *   "PASS   BaseAudioContext.prototype does not have an own property of
+     *       'startRendering'."
+     */
+    notHaveOwnProperty () {
+      this._processArguments(arguments);
+
+      return this._assert(
+          !this._actual.hasOwnProperty(this._expected),
+          '${actual} does not have an own property of "${expected}".',
+          '${actual} has an own the property of "${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}".');
+    }
   }
 
 

third_party/WebKit/LayoutTests/webaudio/unit-tests/audit-expected.txt

@@ -36,10 +36,14 @@ PASS   1 is less than or equal to 1.
 PASS   1 is equal to 1. 
 PASS   should(1).beEqualTo(1) is true. 
 PASS   The message is truthful! 
+PASS   BaseAudioContext.prototype has an own property of "createGain". 
+PASS   BaseAudioContext.prototype does not have an own property of "startRendering". 
+PASS   An AudioBufferSourceNode inherits from "AudioScheduledSourceNode". 
+PASS   An AudioBufferSourceNode inherits from "AudioNode". 
 PASS   Decoding audio data with no argument rejected correctly with TypeError: Failed to execute 'decodeAudioData' on 'BaseAudioContext': 1 argument required, but only 0 present.. 
 PASS   Suspending OAC with no argument rejected correctly with TypeError. 
 PASS   Start OAC rendering resolved correctly. 
-PASS < [basic] All assertions passed. (total 22 assertions) 
+PASS < [basic] All assertions passed. (total 26 assertions) 
 PASS > [load-file-in-should] Test Audit.loadFileFromUrl() within |should| assertion. 
 PASS   Loading file within should().beResolved() resolved correctly. 
 PASS < [load-file-in-should] All assertions passed. (total 1 assertions) 

third_party/WebKit/LayoutTests/webaudio/unit-tests/audit.html

@@ -36,6 +36,18 @@
         should(should(1).beEqualTo(1), 'should(1).beEqualTo(1)').beTrue();
         should(true, 'The message is').message('truthful!', 'false!');
 
+        should(BaseAudioContext.prototype, 'BaseAudioContext.prototype')
+            .haveOwnProperty('createGain');
+        should(BaseAudioContext.prototype, 'BaseAudioContext.prototype')
+            .notHaveOwnProperty('startRendering');
+
+        let ac = new AudioContext();
+        let sourceNode = new AudioBufferSourceNode(ac);
+        should(sourceNode, 'An AudioBufferSourceNode')
+            .inheritFrom('AudioScheduledSourceNode');
+        should(sourceNode, 'An AudioBufferSourceNode')
+            .inheritFrom('AudioNode');
+
         let oac = new OfflineAudioContext(1, 128, 44100);
         Promise.all([
             should(oac.startRendering(), 'Start OAC rendering').beResolved(),