Form actions and useFormStatus in React
React interview exercise on React 19, difficulty 2 of 3. Solve it in the editor beside a worked example; the tests run the moment you do.
Write Comments({ post }): a form with <textarea name="text"> and a SubmitButton (a separate component using useFormStatus, disabled and reading "Posting…" while pending, "Post" otherwise). The form's action calls post(text) and then adds the text to a list rendered as <li className="comment">. Blank text must not be posted.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Progress is saved in your browser, and in your account if you sign in.