react-testing-library why is toBeInTheDocument() not a function

Question

Here is my code for a tooltip that toggles the CSS property display: block on MouseOver and on Mouse Out display: none.

 it(\'should sho         


        

Answer 1

As mentioned by Giorgio, you need to install jest-dom. Here is what worked for me:

(I was using typescript)

npm i --save-dev @testing-library/jest-dom

Then add an import to your setupTests.ts

import '@testing-library/jest-dom/extend-expect';

Then in your jest.config.js you can load it via:

"setupFilesAfterEnv": [
    "/src/setuptests.ts"
  ]