TypeError: environment.setup is not a function in React Testing

Question

I was trying to implement the example shown in Jest website: Getting started with Jest.

While running npm test on I was getting the following error:

<

Answer 1

My issue solve with this:
.
If you have both react-scripts and jest in your package.json, delete jest from it.
Then delete package-lock.json, yarn.lock and node_modules.
Then run npm install (or yarn if you use it). ~Dan Abramov~ . issues #5119 .