fix(viewer): Pause audio instead of muting it if autoplay is prevented

src/lib/viewers/media/MP3Viewer.js

@@ -34,6 +34,33 @@ class MP3Viewer extends MediaBaseViewer {
         this.mediaControls.show();
         this.mediaControls.resizeTimeScrubber();
     }
+
+    /**
+     * Determines if media should autoplay based on cached settings value.
+     *
+     * @override
+     * @emits volume
+     * @return {Promise}
+     */
+    autoplay() {
+        const autoPlayPromise = this.mediaEl.play();
+
+        if (autoPlayPromise && typeof autoPlayPromise.then === 'function') {
+            return autoPlayPromise
+                .then(() => {
+                    this.handleRate();
+                    this.handleVolume();
+                })
+                .catch(() => {
+                    // Auto-play was prevented, pause
+                    this.mediaEl.pause();
+                });
+        }
+
+        // Fallback to traditional autoplay tag if play does not return a promise
+        this.mediaEl.autoplay = true;
+        return Promise.resolve();
+    }
 }
 
 export default MP3Viewer;

src/lib/viewers/media/MediaBaseViewer.js

@@ -317,15 +317,22 @@ class MediaBaseViewer extends BaseViewer {
         const autoPlayPromise = this.mediaEl.play();
 
         if (autoPlayPromise && typeof autoPlayPromise.then === 'function') {
-            this.handleRate();
             return autoPlayPromise
                 .then(() => {
+                    this.handleRate();
                     this.handleVolume();
                 })
                 .catch(() => {
                     // Auto-play was prevented, try muted play
                     this.setVolume(0);
-                    this.mediaEl.play();
+                    this.mediaEl
+                        .play()
+                        .then(() => {
+                            this.handleRate();
+                        })
+                        .catch(() => {
+                            this.mediaEl.pause();
+                        });
                 });
         }
 

src/lib/viewers/media/__tests__/MP3Viewer-test.js

@@ -74,4 +74,17 @@ describe('lib/viewers/media/MP3Viewer', () => {
             mp3.loadUI();
         });
     });
+
+    describe('autoplay()', () => {
+        it('should pause autoplay if the promise is rejected', done => {
+            mp3.mediaEl = {
+                play: sandbox.stub().returns(Promise.reject()),
+                pause: sandbox.stub(),
+            };
+            mp3.autoplay().then(() => {
+                expect(mp3.mediaEl.pause).to.be.called;
+                done();
+            });
+        });
+    });
 });