This project was bootstrapped with Create React App. It is based on the tyepscript template.
Besides the one test that's automatically provided in src/App.test.tsx, there are two additional tests on the remaining two elements rendered in the <App /> component: the prompt (the text within the <p /> element) and the logo (the <img /> element).
You can learn more in the Create React App documentation.
To learn React, check out the React documentation.