Polyfill HTMLMediaElement.play

Return a `Promise` to match the new standard.

src/legacy/htmlMediaElement.js

@@ -0,0 +1,26 @@
+/**
+ * Polyfill for HTMLMediaElement
+ * - HTMLMediaElement.play
+ *   Return a `Promise`.
+ */
+
+(function (HTMLMediaElement) {
+    'use strict';
+
+    const HTMLMediaElement_proto = HTMLMediaElement.prototype;
+    const real_play = HTMLMediaElement_proto.play;
+
+    HTMLMediaElement_proto.play = function () {
+        try {
+            const promise = real_play.apply(this, arguments);
+
+            if (typeof promise?.then === 'function') {
+                return promise;
+            }
+
+            return Promise.resolve();
+        } catch (err) {
+            return Promise.reject(err);
+        }
+    };
+}(HTMLMediaElement));