Error: File .../__mocks__/redis_storage.ts is not under 'rootDir'. 'rootDir' is expected to contain all source files

[abrasat]

The error above occurs when adding the cache_external tests (in "utils/__ tests __/cache_external.ts") and the custom redis mock implementation in __ mocks __.
I found some discussions regarding this error, but dont know exactly how to solve it in the api-example sample project
https://stackoverflow.com/questions/55753163/package-json-is-not-under-rootdir/61467483
https://github.com/clytras/typescript-monorepo