This is passed a media query string identical to those used in CSS. fineProperty(window, 'matchMedia', ' statement to make it a module. Fortunately, it’s possible to respond to CSS3 media query state changes within JavaScript.

This solution requires the css-mediaquery npm package. AnswerĪfter realizing I couldn't actually test my queries with jest-matchmedia-mock, I changed the original answer a bit to be able to mock the behavior of dynamic query matches. The Window interface’s matchMedia() method essentially attaches listeners to media queries, but doesn’t respond to every change in window or screen size, leading to significantly better performance. To do this, use the window.matchMedia method. In fact, the query you pass into useMediaQuery will just match true whenever your code calls window.matchMedia with that same query, regardless of the actual 'window width'. Before you can evaluate the results of a media query, you need to create the MediaQueryList object representing the query. However, from what I've understood after trying to use it for 3 hours was that when you call useMediaQuery, the previous queries you've made no longer work. If you only need to test one query at a time and your tests don't rely on multiple matches, jest-matchmedia-mock was useful. The Window interface's matchMedia() method returns a new MediaQueryList object that can then be used to determine if the document matches the media query string, as well as to monitor the document to detect when it matches (or stops matching) that media query. I had some React hooks and components that needed to listen to multiple different queries with possibly different matches. In my case, the answer was not enough, as window.matchMedia would always return false (or true if you change it).

Window matchmedia