useReducedMotion hook: guard the reference to window (#17165)

Fixes a bug where a naked reference to `window` will crash if used in a SSR context where there's no `window`.
WordPress · Aug 27, 2019 · 9c58193 · 9c58193
1 parent 4d0d290
commit 9c58193
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/packages/compose/src/hooks/use-reduced-motion/index.js b/packages/compose/src/hooks/use-reduced-motion/index.js
@@ -8,7 +8,9 @@ import useMediaQuery from '../use-media-query';
  *
  * @type {boolean}
  */
-const IS_IE = window.navigator.userAgent.indexOf( 'Trident' ) >= 0;
+const IS_IE =
+	typeof window !== 'undefined' &&
+	window.navigator.userAgent.indexOf( 'Trident' ) >= 0;
 
 /**
  * Hook returning whether the user has a preference for reduced motion.