testing-reactlisted

# Testing React Hooks Use `renderHook` and `act` from `@testing-library/react`. Don't write a probe component — `renderHook` is the affordance for testing a hook in isolation. ```tsx import { useMyHook } from "./use-my-hook.ts"; import { act, renderHook } from "@testing-library/react"; const { result, rerender, unmount } = renderHook(() => useMyHook(arg)); expect(result.current).toBe(/* ... */); ``` `renderHook` needs DOM globals. A typical React project provides them through its configured test environment (jsdom or happy-dom), so no per-test setup is required.