The project relies on Bundler and yarn for ruby and javascript dependencies.
bundle install # Installs ruby dependencies specified in Gemfile with bundler
bundle exec rake yarn:install # Installs javascript dependencies specified in package.json with yarn
Karma is the test runner for the javascript tests. Tests sit in the same directory as the javascript i.e. app/javascript.
npm test
or
bundle exec rake test:js
The javascript is written in ES6 and relies on webpack (managed by the rails webpacker gem) to transform and bundle it into ES5. It is located in the app/javascript directory.
The app generally uses the default configuration as provided by webpacker, which can be found in config/webpacker.yml.
Webpacker will automatically compile the javascript when rails server is run. There are also 2 binstubs available: ./bin/webpack and ./bin/webpack-dev-server. If you run ./bin/webpack-dev-server it will watch and incrementally rebuild your javascript on save (which is a lot quicker).
There is also a Procfile used by foreman for when you wish to have your Rails server and webpack-dev-server running side by side:
foreman start
Before the webpacker gem was introduced, it used to be the case that javascript assets would have to be precompiled before pushing your work to Github. This is no longer necessary 🙌