This is a boiled down example of a bug with Jest's code coverage reporting, when used in combination with the default caching and a monorepo (Lerna).

Replicate

1. Clone the repository
2. Run npm install && npm run bootstrap
3. Run npm run test:nocache, and note in stdout that project1/index.js and project2/index.js both have 100% coverage. This is the result of running the tests with the --no-cache flag
4. Run npm run test:cache, and note in stdout we only see code coverage for 1 project. This is the result of running the tests with no flags
5. Run npm run test:ohno, and note in stdout we only see code coverage for 1 project. This is the result of running the tests with --no-cache and -i