feat: Get video playback quality (#16)

package.json

@@ -36,7 +36,7 @@
   "dependencies": {
     "global": "^4.3.2",
     "video.js": "^6.0.1",
-    "videojs-swf": "^5.2.0"
+    "videojs-swf": "^5.4.0"
   },
   "devDependencies": {
     "husky": "^0.13.1",

src/js/index.js

@@ -340,6 +340,29 @@ class Flash extends Tech {
     return false;
   }
 
+  /**
+   * Gets available media playback quality metrics as specified by the W3C's Media
+   * Playback Quality API.
+   *
+   * @see [Spec]{@link https://wicg.github.io/media-playback-quality}
+   *
+   * @return {Object}
+   *         An object with supported media playback quality metrics
+   */
+  getVideoPlaybackQuality() {
+    const videoPlaybackQuality = this.el_.vjs_getProperty('getVideoPlaybackQuality');
+
+    if (window.performance && typeof window.performance.now === 'function') {
+      videoPlaybackQuality.creationTime = window.performance.now();
+    } else if (window.performance &&
+               window.performance.timing &&
+               typeof window.performance.timing.navigationStart === 'number') {
+      videoPlaybackQuality.creationTime =
+        window.Date.now() - window.performance.timing.navigationStart;
+    }
+
+    return videoPlaybackQuality;
+  }
 }
 
 // Create setters and getters for attributes

test/index.test.js

@@ -1,6 +1,7 @@
 import Flash from '../src/js';
 import {createTimeRange} from 'video.js';
 import {document} from 'global';
+import {window} from 'global/window';
 import sinon from 'sinon';
 import QUnit from 'qunitjs';
 
@@ -261,3 +262,78 @@ QUnit.test('duration returns NaN, Infinity or duration according to the HTML sta
               'duration returns duration property when readyState' +
               ' and duration property are both higher than 0');
 });
+
+QUnit.test('getVideoPlaybackQuality API exists', function(assert) {
+  const propertyCalls = [];
+  const videoPlaybackQuality = { test: 'test' };
+  const mockFlash = {
+    el_: {
+      /* eslint-disable camelcase */
+      vjs_getProperty(attr) {
+        propertyCalls.push(attr);
+        return videoPlaybackQuality;
+      }
+      /* eslint-enable camelcase */
+    }
+  };
+
+  assert.deepEqual(Flash.prototype.getVideoPlaybackQuality.call(mockFlash),
+                   videoPlaybackQuality,
+                   'called to get property from flash');
+  assert.equal(propertyCalls.length, 1, 'only one property call');
+  assert.equal(propertyCalls[0],
+               'getVideoPlaybackQuality',
+               'called for getVideoPlaybackQuality');
+});
+
+QUnit.test('getVideoPlaybackQuality uses best available creationTime', function(assert) {
+  const origPerformance = window.performance;
+  const origDate = window.Date;
+  const videoPlaybackQuality = {};
+  const mockFlash = {
+    el_: {
+      /* eslint-disable camelcase */
+      vjs_getProperty(attr) {
+        return videoPlaybackQuality;
+      }
+      /* eslint-enable camelcase */
+    }
+  };
+
+  window.performance = void 0;
+  assert.notOk(Flash.prototype.getVideoPlaybackQuality.call(mockFlash).creationTime,
+               'no creationTime when no performance API available');
+
+  window.performance = {
+    timing: {}
+  };
+  assert.notOk(Flash.prototype.getVideoPlaybackQuality.call(mockFlash).creationTime,
+               'no creationTime when performance API insufficient');
+
+  window.performance = {
+    now: () => 4
+  };
+  assert.equal(Flash.prototype.getVideoPlaybackQuality.call(mockFlash).creationTime,
+               4,
+               'creationTime is performance.now when available');
+
+  window.Date = {
+    now: () => 10
+  };
+  window.performance = {
+    timing: {
+      navigationStart: 3
+    }
+  };
+  assert.equal(Flash.prototype.getVideoPlaybackQuality.call(mockFlash).creationTime,
+               7,
+               'creationTime uses Date.now() - navigationStart when available');
+
+  window.performance.now = () => 4;
+  assert.equal(Flash.prototype.getVideoPlaybackQuality.call(mockFlash).creationTime,
+               4,
+               'creationTime prioritizes performance.now when available');
+
+  window.Date = origDate;
+  window.performance = origPerformance;
+});