tests: fix window.matchMedia is not a function

src/setupTests.js

@@ -10,3 +10,18 @@
 // expect(element).toHaveTextContent(/react/i)
 // learn more: https://github.com/testing-library/jest-dom
 import "@testing-library/jest-dom/extend-expect";
+
+//Mocking matchMedia: https://jestjs.io/docs/en/manual-mocks#mocking-methods-which-are-not-implemented-in-jsdom
+Object.defineProperty(window, "matchMedia", {
+  writable: true,
+  value: jest.fn().mockImplementation((query) => ({
+    matches: false,
+    media: query,
+    onchange: null,
+    addListener: jest.fn(), // deprecated
+    removeListener: jest.fn(), // deprecated
+    addEventListener: jest.fn(),
+    removeEventListener: jest.fn(),
+    dispatchEvent: jest.fn(),
+  })),
+});