Core Contribution

We are very happy about anyone that wants to improve this project! Please make sure to read this guide before starting your work to avoid unnecessary trouble down the road! Always feel welcomed to reach out to us via Gitter or mail if you are unsure or need further information.

What to work on

If you want to contribute and are unsure what to work on, take a look at the open issues!

Other case: You plan to built something that you think should be part of the Matestack UI Core (or you have already built it)? Great, then open a pull request and we will take a look!

How to contribute

Please create a pull request to the develop branch with your tested and documented code. Bonus points for using our PR template!


Documentation can be found in the /docs folder. Please make sure to cover basic use cases of your concepts & components for other users! Feel free to take a look at other examples and copy their structure!

Note: We will not approve pull requests that introduce new concepts or components without documentation. Same goes for existing concepts & components. If you change the behavior of an existing part of this project, make sure to also update the corresponding part of the documentation!

Core Components

Core Components are an essential part of the matestack-ui-core gem. If you are planning to contribute to Matestack you can start doing that by creating a core component. To help you getting started you can use the Core Component Generator.

The generator will create a matestack core component to app/concepts/matestack/ui/core.


rails generate matestack:core:component div

This will create a component for the HTML <div> tag and will generate the following files:



To assure this project is and remains in great condition, we heavily rely on automated tests. Tests are defined in /spec folder and can be executed by running:

bundle exec rspec

Tests follow quite the same rules as the documentation: Make sure to either add relevant tests (when introducing new concepts or components) or change existing ones to fit your changes (updating existing concepts and components). Pull requests that add/change concepts & components and do not come with corresponding tests will not be approved.

 Note: Running tests on macOS

Make sure you have installed chromedriver on your machine. You can install chromedriver via brew with

brew cask install chromedriver

You can then run your the testsuite with bundle exec rspec.

If you get an error about a version mismatch similar to this one:

Chrome version must be between X and Y (Driver info: chromedriver=X.Y.Z)

Make sure you update your chromedriver by executing this command in the project root:

rails app:webdrivers:chromedriver:update


Webpacker is used for managing all JS assets. In order to deploy a packed JS, we use a "builder" app found in repo_root/builder. This builder app uses a symlink in order to reference the actual core found in builder/vendor.

You can run webpacker inside this builder app to pack JS assets:

cd builder



./bin/webpack --watch

All webpack configuration can be found within the builder folder.

For further webpacker documentation: webpacker