**Before submitting a pull request,** please make sure the following is done:

1. Fork [the repository](https://github.com/facebook/react) and create your branch from `master`.
2. If you've added code that should be tested, add tests!
3. If you've changed APIs, update the documentation.
4. Ensure the test suite passes (`npm test`).
5. Format your code with [prettier](https://github.com/prettier/prettier) (`npm run prettier`).
6. Make sure your code lints (`npm run lint`).
7. Run the [Flow](https://flowtype.org/) typechecks (`npm run flow`).
8. If you added or removed any tests, run `./scripts/fiber/record-tests` before submitting the pull request, and commit the resulting changes.
9. If you haven't already, complete the CLA.