Fixed error when using chrome autofill

packages/react-shortcuts/CHANGELOG.md

@@ -16,3 +16,7 @@ and adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 ### Added
 
 - This CHANGELOG [(#508)](https://github.com/Shopify/quilt/pull/508)
+
+### Fixed
+
+- Added a check for event.getModifierState method before calling it.  ([#1578](https://github.com/Shopify/quilt/pull/1578))

packages/react-shortcuts/src/ShortcutManager/ShortcutManager.tsx

@@ -67,7 +67,10 @@ export default class ShortcutManager {
     }
 
     function keyGroupIsHeld(keyGroup: ModifierKey[]) {
-      return keyGroup.every((key: ModifierKey) => event.getModifierState(key));
+      return keyGroup.every(
+        (key: ModifierKey) =>
+          event.getModifierState && event.getModifierState(key),
+      );
     }
 
     return hasKeyGroups(heldKeys)

packages/react-shortcuts/src/tests/ShortcutManager.test.tsx

@@ -297,6 +297,22 @@ describe('ShortcutManager', () => {
 
       expect(fooSpy).not.toHaveBeenCalled();
     });
+
+    it('doesn’t fire on non-keyboard events', () => {
+      const matchSpy = jest.fn();
+      const heldGroup: ModifierKey[] = ['Control', 'Shift'];
+      const heldToCheck: HeldKey = [[...heldGroup], ['Alt', 'Meta']];
+
+      mount(
+        <ShortcutProvider>
+          <Shortcut held={heldToCheck} ordered={['/']} onMatch={matchSpy} />
+        </ShortcutProvider>,
+      );
+
+      document.dispatchEvent(new UIEvent('keydown'));
+
+      expect(matchSpy).not.toHaveBeenCalled();
+    });
   });
 });