jest: Incorrect transform for multiple projects with different transform in the same process

Do you want to request a feature or report a bug? Report a bug

What is the current behavior? Jest uses the same transform for projects with different transform behavior if they run in the same process.

If the current behavior is a bug, please provide the steps to reproduce and either a repl.it demo through https://repl.it/languages/jest or a minimal repository on GitHub that we can yarn install and yarn test.

Repository https://github.com/amosyuen/jest-projects-transform-error. Running yarn test succeeds. But running yarn test --runInBand will fail. Error message indicates that the incorrect babel transform was used.

What is the expected behavior? Correct transform for the project should be used. Both yarn test and yarn test --runInBand should succeed.

Please provide your exact Jest configuration https://github.com/amosyuen/jest-projects-transform-error/blob/master/jest.config.js

Run npx envinfo --preset jest in your project directory and paste the results here

Environment: OS: Windows 10 Node: 8.9.4 Yarn: 1.5.1 npm: 5.6.0 Watchman: Not Found Xcode: N/A Android Studio: Version 3.0.0.0 AI-171.4443003