feat: expose canChangeType on the VHS property (#911)

src/source-updater.js

@@ -428,12 +428,23 @@ export default class SourceUpdater extends videojs.EventTarget {
    * @return {boolean}
    *         if changeType can be called.
    */
-  canChangeType() {
+  static canChangeType() {
     return window.SourceBuffer &&
         window.SourceBuffer.prototype &&
         typeof window.SourceBuffer.prototype.changeType === 'function';
   }
 
+  /**
+   * Whether or not the changeType function is supported
+   * on our SourceBuffers.
+   *
+   * @return {boolean}
+   *         if changeType can be called.
+   */
+  canChangeType() {
+    return this.constructor.canChangeType();
+  }
+
   /**
    * Call the changeType function on a source buffer, given the code and type.
    *

src/videojs-http-streaming.js

@@ -21,6 +21,7 @@ import { MasterPlaylistController } from './master-playlist-controller';
 import Config from './config';
 import renditionSelectionMixin from './rendition-mixin';
 import PlaybackWatcher from './playback-watcher';
+import SourceUpdater from './source-updater';
 import reloadSourceOnError from './reload-source-on-error';
 import {
   lastBandwidthSelector,
@@ -902,6 +903,10 @@ class VhsHandler extends Component {
     return this.constructor.version();
   }
 
+  canChangeType() {
+    return SourceUpdater.canChangeType();
+  }
+
   /**
    * Begin playing the video.
    */

test/videojs-http-streaming.test.js

@@ -192,6 +192,24 @@ QUnit.test('version is exported', function(assert) {
 
 });
 
+QUnit.test('canChangeType is exported', function(assert) {
+  this.player.src({
+    src: 'manifest/playlist.m3u8',
+    type: 'application/vnd.apple.mpegurl'
+  });
+
+  this.clock.tick(1);
+
+  assert.ok(this.player.tech(true).vhs.canChangeType, 'canChangeType function');
+
+  const canChangeType = window.SourceBuffer &&
+        window.SourceBuffer.prototype &&
+        typeof window.SourceBuffer.prototype.changeType === 'function';
+  const assertion = canChangeType ? 'ok' : 'notOk';
+
+  assert[assertion](this.player.tech(true).vhs.canChangeType(), 'canChangeType is correct');
+});
+
 QUnit.test('deprecation warning is show when using player.hls', function(assert) {
   const oldWarn = videojs.log.warn;
   let warning = '';