From dd1b478e4db84c8611b3705c15615e881a441c01 Mon Sep 17 00:00:00 2001
From: Alex Barstow <abarstow@brightcove.com>
Date: Mon, 16 May 2022 17:48:01 -0400
Subject: [PATCH] feat: assume native promises, remove promise option and
 workarounds (#7715)

BREAKING CHANGE: Removes support for Promise class option and assumes native Promise is available. Will break in older browsers or devices.
---
 src/js/player.js                | 123 ++++++++++++++------------------
 src/js/tech/tech.js             |   6 +-
 test/unit/utils/promise.test.js |   6 --
 3 files changed, 53 insertions(+), 82 deletions(-)

diff --git a/src/js/player.js b/src/js/player.js
index fbeaf96762..d593930325 100644
--- a/src/js/player.js
+++ b/src/js/player.js
@@ -1177,8 +1177,7 @@ class Player extends Component {
       'playerElIngest': this.playerElIngest_ || false,
       'vtt.js': this.options_['vtt.js'],
       'canOverridePoster': !!this.options_.techCanOverridePoster,
-      'enableSourceset': this.options_.enableSourceset,
-      'Promise': this.options_.Promise
+      'enableSourceset': this.options_.enableSourceset
     };
 
     TRACK_TYPES.names.forEach((name) => {
@@ -2324,15 +2323,9 @@ class Player extends Component {
    *         the promise from play is fulfilled.
    */
   play() {
-    const PromiseClass = this.options_.Promise || window.Promise;
-
-    if (PromiseClass) {
-      return new PromiseClass((resolve) => {
-        this.play_(resolve);
-      });
-    }
-
-    return this.play_();
+    return new Promise((resolve) => {
+      this.play_(resolve);
+    });
   }
 
   /**
@@ -2820,38 +2813,32 @@ class Player extends Component {
    * @fires Player#fullscreenchange
    */
   requestFullscreen(fullscreenOptions) {
-    const PromiseClass = this.options_.Promise || window.Promise;
+    const self = this;
 
-    if (PromiseClass) {
-      const self = this;
-
-      return new PromiseClass((resolve, reject) => {
-        function offHandler() {
-          self.off('fullscreenerror', errorHandler);
-          self.off('fullscreenchange', changeHandler);
-        }
-        function changeHandler() {
-          offHandler();
-          resolve();
-        }
-        function errorHandler(e, err) {
-          offHandler();
-          reject(err);
-        }
-
-        self.one('fullscreenchange', changeHandler);
-        self.one('fullscreenerror', errorHandler);
+    return new Promise((resolve, reject) => {
+      function offHandler() {
+        self.off('fullscreenerror', errorHandler);
+        self.off('fullscreenchange', changeHandler);
+      }
+      function changeHandler() {
+        offHandler();
+        resolve();
+      }
+      function errorHandler(e, err) {
+        offHandler();
+        reject(err);
+      }
 
-        const promise = self.requestFullscreenHelper_(fullscreenOptions);
+      self.one('fullscreenchange', changeHandler);
+      self.one('fullscreenerror', errorHandler);
 
-        if (promise) {
-          promise.then(offHandler, offHandler);
-          promise.then(resolve, reject);
-        }
-      });
-    }
+      const promise = self.requestFullscreenHelper_(fullscreenOptions);
 
-    return this.requestFullscreenHelper_();
+      if (promise) {
+        promise.then(offHandler, offHandler);
+        promise.then(resolve, reject);
+      }
+    });
   }
 
   requestFullscreenHelper_(fullscreenOptions) {
@@ -2876,6 +2863,7 @@ class Player extends Component {
     if (this.fsApi_.requestFullscreen) {
       const promise = this.el_[this.fsApi_.requestFullscreen](fsOptions);
 
+      // Even on browsers with promise support this may not return a promise
       if (promise) {
         promise.then(() => this.isFullscreen(true), () => this.isFullscreen(false));
       }
@@ -2898,45 +2886,40 @@ class Player extends Component {
    * @fires Player#fullscreenchange
    */
   exitFullscreen() {
-    const PromiseClass = this.options_.Promise || window.Promise;
-
-    if (PromiseClass) {
-      const self = this;
+    const self = this;
 
-      return new PromiseClass((resolve, reject) => {
-        function offHandler() {
-          self.off('fullscreenerror', errorHandler);
-          self.off('fullscreenchange', changeHandler);
-        }
-        function changeHandler() {
-          offHandler();
-          resolve();
-        }
-        function errorHandler(e, err) {
-          offHandler();
-          reject(err);
-        }
-
-        self.one('fullscreenchange', changeHandler);
-        self.one('fullscreenerror', errorHandler);
+    return new Promise((resolve, reject) => {
+      function offHandler() {
+        self.off('fullscreenerror', errorHandler);
+        self.off('fullscreenchange', changeHandler);
+      }
+      function changeHandler() {
+        offHandler();
+        resolve();
+      }
+      function errorHandler(e, err) {
+        offHandler();
+        reject(err);
+      }
 
-        const promise = self.exitFullscreenHelper_();
+      self.one('fullscreenchange', changeHandler);
+      self.one('fullscreenerror', errorHandler);
 
-        if (promise) {
-          promise.then(offHandler, offHandler);
-          // map the promise to our resolve/reject methods
-          promise.then(resolve, reject);
-        }
-      });
-    }
+      const promise = self.exitFullscreenHelper_();
 
-    return this.exitFullscreenHelper_();
+      if (promise) {
+        promise.then(offHandler, offHandler);
+        // map the promise to our resolve/reject methods
+        promise.then(resolve, reject);
+      }
+    });
   }
 
   exitFullscreenHelper_() {
     if (this.fsApi_.requestFullscreen) {
       const promise = document[this.fsApi_.exitFullscreen]();
 
+      // Even on browsers with promise support this may not return a promise
       if (promise) {
         // we're splitting the promise here, so, we want to catch the
         // potential error so that this chain doesn't have unhandled errors
@@ -3524,9 +3507,7 @@ class Player extends Component {
    * and calls `reset` on the `tech`.
    */
   reset() {
-    const PromiseClass = this.options_.Promise || window.Promise;
-
-    if (this.paused() || !PromiseClass) {
+    if (this.paused()) {
       this.doReset_();
     } else {
       const playPromise = this.play();
diff --git a/src/js/tech/tech.js b/src/js/tech/tech.js
index 8c237a041b..92e55307dc 100644
--- a/src/js/tech/tech.js
+++ b/src/js/tech/tech.js
@@ -831,11 +831,7 @@ class Tech extends Component {
    * @abstract
    */
   requestPictureInPicture() {
-    const PromiseClass = this.options_.Promise || window.Promise;
-
-    if (PromiseClass) {
-      return PromiseClass.reject();
-    }
+    return Promise.reject();
   }
 
   /**
diff --git a/test/unit/utils/promise.test.js b/test/unit/utils/promise.test.js
index 2171024fc1..bafd76fadb 100644
--- a/test/unit/utils/promise.test.js
+++ b/test/unit/utils/promise.test.js
@@ -5,12 +5,6 @@ import * as promise from '../../../src/js/utils/promise';
 QUnit.module('utils/promise');
 
 QUnit.test('can correctly identify a native Promise (if supported)', function(assert) {
-
-  // If Promises aren't supported, skip this.
-  if (!window.Promise) {
-    return assert.expect(0);
-  }
-
   assert.ok(promise.isPromise(new window.Promise((resolve) => resolve())), 'a native Promise was recognized');
 });