Gutenberg is a Node-based project, built primarily in JavaScript. Be sure to have Node installed first. If you already have Node installed, make sure it's version 6.10.3 or higher for this plugin to work correctly. You can check your Node version by typing node -v in the Terminal prompt.
To test the plugin, or to contribute to it, you can clone this repository and build the plugin files using Node. How you do that depends on whether you're developing locally or uploading the plugin to a remote host.
Open a terminal (or if on Windows, a command prompt) and navigate to the repository you cloned. Now type npm install to get the dependencies all set up. Once that finishes, you can type npm run build. You can now upload the entire repository to your wp-content/plugins directory on your webserver and activate the plugin from the WordPress admin. You'll get a separate WordPress menu item called Gutenberg.
You can also type npm run package-plugin which will run the two commands above and create a zip file automatically for you which you can use to install Gutenberg through the WordPress admin.
If you have a local WordPress environment, you can clone this repository right into your wp-content/plugins directory. npm install will get the dependencies set up. Then you can type npm run dev in your terminal or command prompt to keep the plugin building in the background as you work on it.
Some good options for a local WordPress development environment include VVV and Mamp.
A good workflow is to work directly in this repo, branch off master, and submit your changes as a pull request.
Ideally name your branches with prefixes and descriptions, like this: [type]/[change]. A good prefix would be:
add/= add a new featuretry/= experimental feature, "tentatively add"update/= update an existing feature
For example, add/gallery-block means you're working on adding a new gallery block.
You can pick among all the tickets, or some of the ones labelled Good First Task.
Gutenberg contains both PHP and JavaScript code, and encourages testing and code style linting for both.
Tests for JavaScript use Mocha as the test runner and Chai BDD as an assertion library (with a small variation on assertion properties). If needed, you can also use Sinon for mocking and Enzyme for React component testing.
Assuming you've followed the instructions above to install Node and project dependencies, tests can be run from the command-line with NPM:
npm test
To run unit tests only, use npm run test-unit instead.
Code style in JavaScript is enforced using ESLint. The above npm test will execute both unit tests and code linting. Code linting can be verified independently by running npm run lint.
Tests for PHP use PHPUnit as the testing framework. Before starting, you should install PHPUnit and have a copy of WordPress Develop available. If the Gutenberg plugin is installed in the context of a WordPress Develop site, you can run phpunit directly from the command-line. Otherwise, you will need to specify the path to WordPress Develop's test directory as an environment variable:
WP_TESTS_DIR=/path/to/wordpress-develop/tests/phpunit phpunit
Code style in PHP is enforced using PHP_CodeSniffer. It is recommended that you install PHP_CodeSniffer and the WordPress-specific code standard ruleset using Composer. With Composer installed, run composer install from the project directory to install dependencies, then composer run-script lint to verify PHP code standards.
If you'd like to contribute to the design or front-end, feel free to contribute to tickets labelled Design. We could use your thoughtful replies, mockups, animatics, sketches, doodles. Proposed changes are best done as minimal and specific iterations on the work that precedes it so we can compare. If you use Sketch, you can grab the source file for the mockups (updated April 6th).