Jest is one of Facebook's open source projects that is both under very active development and is also being used to ship code to everybody on facebook.com. We're still working out the kinks to make contributing to this project as easy and transparent as possible, but we're not quite there yet. Hopefully this document makes the process for contributing clear and answers some questions that you may have.
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
The core team works directly on GitHub and all work is public.
We will do our best to keep master
in good shape, with tests passing at all times. But in order to move fast, we will make API changes that your application might not be compatible with. We will do our best to communicate these changes and always version appropriately so you can lock into a specific version if need be.
The core team will be monitoring for pull requests. When we get one, we'll run some Facebook-specific integration tests on it first. From here, we'll need to get another person to sign off on the changes and then merge the pull request. For API changes we may need to fix internal uses, which could cause some delay. We'll do our best to provide updates and feedback throughout the process.
Before submitting a pull request, please make sure the following is done…
-
Fork the repo and create your branch from
master
. A guide on how to fork a repository: https://help.github.com/articles/fork-a-repo/Open terminal (e.g. Terminal, iTerm, Git Bash or Git Shell) and type:
git clone https://github.com/<your_username>/jest cd jest git checkout -b my_branch
Note: Replace
<your_username>
with your GitHub username -
Jest uses Yarn for running development scripts. If you haven't already done so, please install yarn.
-
Run
yarn install
. On Windows: To install Yarn on Windows you may need to download either node.js or Chocolateyyarn install
To check your version of Yarn and ensure it's installed you can type:
yarn --version
-
If you've added code that should be tested, add tests. You can use watch mode that continuously transforms changed files to make your life easier.
# in the background yarn run watch
-
If you've changed APIs, update the documentation.
-
Ensure the test suite passes via
yarn test
. To run the test suite you may need to install Mercurial (hg
). On macOS, this can be done using homebrew:brew install hg
.brew install hg # maybe yarn test
-
If you haven't already, complete the CLA.
If you are making changes to the website or documentation, test the website folder and run the server to check if your changes are being displayed accurately.
- Locate to the website directory and install any website specific dependencies
by typing in
yarn
. Following steps are to be followed for this purpose from the root directory.cd website # Only needed if you are not already in the website directory yarn yarn test
- You can run a development server to check if the changes you made are being
displayed accurately by running
yarn start
in the website directory.
In order to accept your pull request, we need you to submit a CLA. You only need to do this once, so if you've done this for another Facebook open source project, you're good to go. If you are submitting a pull request for the first time, just let us know that you have completed the CLA and we can cross-check with your GitHub username.
To link jest
on the command line to jest-cli/bin/jest.js
in a development build:
cd /path/to/your/Jest_clone/packages/jest-cli
yarn link
To build Jest:
cd /path/to/your/Jest_clone
# Do one of the following:
# Check out a commit from another contributor, and then
yarn run build
# Or, save your changes to Jest, and then
yarn test # which also builds Jest
To run tests in another project with the development build of Jest:
cd /path/to/another/project
jest [options] # run jest-cli/bin/jest.js in the development build
- To decide whether to specify any options, see
test
underscripts
in thepackage.json
file of the other project.
To unlink jest
on the command line from jest-cli/bin/jest.js
in a development build:
yarn unlink jest-cli
We will be using GitHub Issues for our public bugs. We will keep a close eye on this and try to make it clear when we have an internal fix in progress. Before filing a new issue, try to make sure your problem doesn't already exist.
The best way to get your bug fixed is to provide a reduced test case. Please provide a public repository with a runnable example.
Facebook has a bounty program for the safe disclosure of security bugs. With that in mind, please do not file public issues; go through the process outlined on that page.
- Discord - #jest on Reactiflux
- 2 spaces for indentation (no tabs).
- 80 character line length strongly preferred.
- Prefer
'
over"
. - ES6 syntax when possible.
- Use Flow types.
- Use semicolons;
- Trailing commas,
- Avd abbr wrds.
By contributing to Jest, you agree that your contributions will be licensed under its BSD license.