This is a small test project to demonstrate an issue in the Enzyme adapter for React 16.14. It was reported right here: enzymejs/enzyme#2553

To demonstrate the problem, run the following:

docker build . -f react.16.14.0.Dockerfile -t mocha_test:16.14.0
docker run --rm mocha_test:16.14.0

This will hang the container and you will need to forcefully stop it.

However, if you do the same with React 16.4.2:

docker build . -f react.16.4.2.Dockerfile -t mocha_test:16.4.2
docker run --rm mocha_test:16.4.2

It works correctly.

I was able to track it down to the import Adapter from 'enzyme-adapter-react-16'; statement in test/my.test.js. If this line is commented out everything works correctly.