Mutation observer is not a constructor (Jest)

Question

I am trying to use Jest with a new CRA project, but I am facing a problem when trying to use the findByText function. I installed:

yarn add -D jest-environment-jsdom-sixteen

And run my tests with react-scripts test --env=jest-environment-jsdom-sixteen. It works fine if I do this solution that I encountered while reading these issues here:

• https://github.com/testing-library/dom-testing-library/issues/477
• https://github.com/testing-library/react-testing-library/issues/662
• https://github.com/testing-library/react-testing-library/issues/731

However I am also using the Jest plugin from VS code and tests do not pass with it. I have tried to do this in my jest.config.js as suggested in the docs:

module.exports = {
  testEnvironment: 'jest-environment-jsdom-sixteen',
};

But it still does not work.

Thanks in advance.

Answer 1

Testing MutationObserver with Jest: Try this, it worked for me, on a similar error:

1. npm i -D mutationobserver-shim
2. import "mutationobserver-shim"; in setupTests.js