I've not yet succeeded in getting any of it to work, but, based on my experiments:

1. Need to import 'fireEvent' from '@testing-library/svelte'
2. Need to import 'waitForElement' from '@testing-library/svelte'
3. Need to install @testing-library/jest-dom in order to get 'toBeInTheDocument' matcher - this is in the docs, but it shouldn't be required for the basic example.