jest.mock("supports-webp", () => Promise.resolve(false)); import { renderHook } from "@testing-library/react-hooks"; import { useWebPSupportCheck } from ".."; describe("useWebPSupportCheck", () => { describe("when WebP isn't supported", () => { it("returns false after update", async () => { const { result, waitForNextUpdate } = renderHook(() => useWebPSupportCheck() ); expect(result.current).toBe(false); await waitForNextUpdate(); expect(result.current).toBe(false); }); }); });