How is testing done for React?

How is testing done for React?

There are several methods for testing React components. Rendering component trees in a reduced test environment and asserting on their output are the two broad categories. End-to-end testing involves running an entire app in a realistic browser environment.

https://reactjs.org/docs/testing.html#:~:text=There%20are%20a%20few%20ways,to-end”%20tests).