[Bug] Unable to run with custom-config in an esm-project

[benbender]

Describe the bug

If I eject the config in an esm-project, the filename test-runner-jest.config.js is interpreted as esm-module and jest will fail to run. As the filename is hardcoded, I'm unable to rename the file to test-runner-jest.config.cjs.

Two possible solutions:

1. make the filename of the config adjustable via parameter
2. test for the existance of test-runner-jest.config.cjs in the cli