3 files changed, 7 insertions, 20 deletions
diff --git a/src/js/utils/elements.js b/src/js/utils/elements.js
index 43f46416..bdf18bfd 100644
--- a/src/js/utils/elements.js
+++ b/src/js/utils/elements.js
@@ -221,7 +221,7 @@ export function hasClass(element, className) {
 
 // Element matches selector
 export function matches(element, selector) {
-    const prototype = Element.prototype;
+    const {prototype} = Element;
 
     function match() {
         return Array.from(document.querySelectorAll(selector)).includes(this);
diff --git a/src/js/utils/is.js b/src/js/utils/is.js
index b005cd31..24f176cc 100644
--- a/src/js/utils/is.js
+++ b/src/js/utils/is.js
@@ -19,7 +19,7 @@ const isEvent = input => instanceOf(input, Event);
 const isKeyboardEvent = input => instanceOf(input, KeyboardEvent);
 const isCue = input => instanceOf(input, window.TextTrackCue) || instanceOf(input, window.VTTCue);
 const isTrack = input => instanceOf(input, TextTrack) || (!isNullOrUndefined(input) && isString(input.kind));
-const isPromise = input => instanceOf(input, Promise);
+const isPromise = input => instanceOf(input, Promise) && isFunction(input.then);
 
 const isEmpty = input =>
     isNullOrUndefined(input) ||
diff --git a/src/js/utils/promise.js b/src/js/utils/promise.js
index 42fcc2c3..f45b46ab 100644
--- a/src/js/utils/promise.js
+++ b/src/js/utils/promise.js
@@ -1,27 +1,14 @@
-/**
- * Returns whether an object is `Promise`-like (i.e. has a `then` method).
- *
- * @param  {Object}  value
- *         An object that may or may not be `Promise`-like.
- *
- * @return {boolean}
- *         Whether or not the object is `Promise`-like.
- */
-export function isPromise(value) {
-    return value !== undefined && value !== null && typeof value.then === 'function';
-}
-
+import is from './is';
 /**
  * Silence a Promise-like object.
- *
  * This is useful for avoiding non-harmful, but potentially confusing "uncaught
  * play promise" rejection error messages.
- *
- * @param  {Object} value
- *         An object that may or may not be `Promise`-like.
+ * @param  {Object} value An object that may or may not be `Promise`-like.
  */
 export function silencePromise(value) {
-    if (isPromise(value)) {
+    if (is.promise(value)) {
         value.then(null, () => {});
     }
 }
+
+export default { silencePromise };