Testing two environments with jest

EDIT (Jan 2018):

It is now possible to do so (since Jest v20), and the option is called projects. Read more about it the docs.

Basically you can define an array of your projects you want Jest to be run within:

{
  "projects": ["<rootDir>/client", "<rootDir>/server", "<rootDir>/some-glob/*"]
}

Just remember every project needs to have its own config. If you want the config to be picked up automatically, put it inside jest.config.js file or like usually in package.json.

If you prefer placing your config somewhere else (e.g. in configs/jest.js), you'll need to point to the path of the config file (with the rootDir option set properly):

{
  "projects": ["<rootDir>/client/configs/jest.js", "<rootDir>/server/configs/jest.js"]
}

ORIGINAL ANSWER:

Currently this is not possible, but there's an issue for that case: https://github.com/facebook/jest/issues/1206.

Feel free to jump in and leave a comment!

You can also use the @jest-environment docblock to set test environments on a per-file basis:

/**
 * @jest-environment jsdom
 */

test('use jsdom in this test file', () => {
  const element = document.createElement('div');
  expect(element).not.toBeNull();
});