- Roadmap
- Before Getting Started
- Discussing non-public features or products
- Developing Components
- Writing documentation
- Creating a pull request
- Deploying & publishing
- Troubleshooting
- Glossary
If you're looking for something to work on, a great place to start is our issues labeled up for grabs! If you've got a feature that you'd like to implement, be sure to check out our Primer Components Roadmap to make sure it hasn't already been started on.
A common question asked about Primer Components is how to know what should be added to Primer Components and what is best left as a local component in a consuming application. Though there are no hard & fast rules about what can and cannot be added to Primer Components, here are a few things we take into consideration:
-
Is the new feature an existing pattern in Primer CSS or related to UI built at GitHub? Primer Components is first and foremost a library for building UI at GitHub - patterns that aren't currently being used in GitHub UI (either on github.com or in a GitHub owned project outside of github.com) probably shouldn't be added to Primer Components. Exceptions to this could be helper components that don't necessarily render UI but help with the development process (like
Flex
,Grid
, orBox
). -
Does the proposed component get used in more than one or two places across GitHub UI? A component that's only meant to be used in one place and doesn't have potential to be reused in many places probably should exist as a local component. An example of something like this might be a component that renders content specific to a single GitHub product.
In general, we tend to be pretty excited about 99% of feature proposals and contributions! If you would like to get started with a component proposal, open an issue using the component proposal template.
As this is a public repo, please be careful not to include details or screenshots from unreleased GitHub products or features. In most cases, a good bug report, feature request, or pull request should be able to describe the work without including business logic or feature details, but if you must discuss context relating to an unreleased feature, please open an issue in the private Design Systems repo and link to it in your issue or pull request.
We primarily use our documentation site as a workspace to develop new components or make changes to existing components (stay tuned for a better development environment coming soon!).
Before running the documentation site locally, you'll need to install packages in the root and docs
directories:
npm install && cd docs && npm install
Then navigate back to the root folder and run the following to start up the site:
npm start
Navigate to http://localhost:8000/ to see the site in your browser ✨
- We use styled-components to style our components.
- We use style functions from styled-system whenever possible, and styled-systems'
style()
function to create new ones.
With a couple of exceptions, all components should be created with the styled
function from [styled-components] and should have the appropriate groups of system props attached.
Default values for system props can be set in Component.defaultProps
.
theme
prop! This can sometimes override the theme provided by the ThemeProvider and cause unexpected theming issues.
Additionally, every component should support the sx
prop; remember to add ${sx}
to the style literal.
Here's an example of a basic component written in the style of Primer Components:
import {TYPOGRAPHY, COMMON} from './constants'
import sx from './sx
const Component = styled.div`
// additional styles here
${COMMON};
${TYPOGRAPHY};
${sx};
`
Component.defaultProps = {
m: 0,
fontSize: 5,
}
export default Component
Each component should have access to the appropriate system props. Every component has access to COMMON
. For most components added, you'll only need to give the component to COMMON
. If you are unsure, ping a DS team member on your PR.
Categories of system props are exported from src/constants.js
:
COMMON
includes color and spacing (margin and padding) propsTYPOGRAPHY
includes font family, font weight, and line-height propsPOSITION
includes positioning propsFLEX
includes flexbox propsBORDER
includes border and box-shadow propsGRID
includes grid props
To give the component access to a group of system props, import the system prop function from ./constants
and include the system prop function in your styled-component like so:
import {COMMON} from './constants'
const Component = styled.div`
// additional styles here
${COMMON};
`
Remember that the system prop function inside your style declaration needs to go after any built-in styles you want to be overridable.
Each component should provide access to a prop called sx
that allows for setting theme-aware ad-hoc styles. See the overriding styles doc for more information on using the prop.
Adding the sx
prop is similar to adding system props; import the default export from the sx
module, add it to your style definition, and add the appropriate prop types. The sx
prop should go at the very end of your style definition.
import {COMMON} from './constants'
import sx from './sx'
const Component = styled.div`
// additional styles here
${COMMON};
${sx};
`
We use the React configuration from GitHub's eslint plugin to lint our JavaScript. To check your work before pushing, run:
npm run lint
Or, you can use npx to run eslint on one or more specific files:
# lint the component and the tests in src/__tests__
npx eslint src/**/MyComponent.js
Protip: The eslint --fix
flag can automatically fix most linting errors, such as those involving whitespace or incorrect ordering of object keys and imports. You can fix those issues across the entire project with:
npm run lint -- --fix
Protip: npm run lint -- --quiet
(or npx eslint --quiet ...
) will suppress warnings so that you can focus on fixing errors.
We test our components with Jest and react-test-renderer. You can run the tests locally with npm test
. To run the tests as you work, run Jest in watch mode with:
npm test -- --watch
See src/__tests__/example.js
for examples of ways that we test our components.
Several of the projects that consume Primer Components are written in TypeScript. Though Primer Components is not currently written in TS, we do export type definitions in order to make Primer Components compatible with other TS projects.
Whenever adding new components or modifying the props of an existing component, please make sure to update the type definition in index.d.ts
! This is super important to make sure we don't break compatibility :)
- Primer Components Philosophy
- Primer Components Core Concepts
- Primer Components System Props
- Styled Components docs
- Styled System docs
We use Doctocat to power our documentation site at https://primer.style/components.
To add a new component to our documentation site, create a new file with the .md
extension for your component in docs/content
(e.g. docs/content/Button.md
).
When creating a new pull request, please follow the guidelines in the auto-populated pull request template. Be sure to add screenshots of any relevant work and a thoughtful description.
After opening a pull request, a member of the design systems team will add the appropriate labels (major, minor, patch release labels) and update the base branch to the correct release branch. Usually, you'll receive a response from the design systems team within a day or two. The design systems team member will review the pull request keeping the following items in mind:
- If it's a new component, does the component make sense to add to Primer Components? (Ideally this is discussed before the pull request stage, please reach out to a DS member if you aren't sure if a component should be added to Primer Components!)
- Does the component follow our Primer Components code style?
- Does the component use theme values for most CSS values?
- Does the component have the correct system props implemented?
- Is the component API intuitive?
- Does the component have the appropriate type definitions in
index.d.ts
? - Is the component documented accurately?
- Does the component have appropriate tests?
- Does the pull request increase the bundle size significantly?
If everything looks great, the design systems team member will approve the pull request and merge when appropriate. Minor and patch changes are released frequently, and we try to bundle up breaking changes and avoid shipping major versions too often. If your pull request is time-sensitive, please let a design systems team member know. You do not need to worry about merging pull requests on your own, we'll take care of that for you :)
All of our documentation sites use the Now integration to deploy documentation changes whenever code is merged into main. The integration also creates a preview site every time you commit code to a branch. To view the preview site, navigate to the PR and find the comment from the now
bot. This will include a link to the preview site for your branch.
Once you merge your branch into main, any changes to the docs will automatically deploy. No further action is necessary.
This site is served as a subdirectory of primer.style using a path alias configured in that repo's rules.json
. If you change the production deployment URL for this app, you will also need to change it there and re-deploy that app; otherwise, Now will automatically route requests from primer.style/components to the new deployment whenever you alias this one to primer-components.now.sh
.
We use changesets to managing versioning, publishing, and release notes. Here's how it works:
- When creating a new PR, changeset-bot will remind you to add a changeset if your change should trigger a new version number for the package.
- To create a new changeset on your local machine, run
npx changeset
and answer the prompts. If you are introducing multiple features in the PR, add a separate changeset for each. - Push your new changes along with the changeset file to your PR; changeset-bot will show that there are valid changesets in the PR.
- When the PR is ready, merge it to the main branch.
- The changeset action will automatically create a new PR that bumps the version number appropriately, creates or updates
CHANGELOG.md
, and shows the release notes that will be used in the GitHub Release notes. - If you want to release more features, merge them into the main branch and changesets will update the release PR. Note that it does this via force-pushing, so you should not edit the release PR yourself.
- When you're ready to release, merge the release PR into the main branch and changesets will publish the new version to npm and create a GitHub Release.
npm start
fails with an error like gatsby: command not found
Make sure to run npm install
from inside the docs/
subfolder as well as the root folder.
npm start
fails with a different error
Ensure you are using the latest minor of Node.js for the major version specified in the .nvmrc
file. For example, if .nvmrc
contains 8
, make sure you're using the latest version of Node.js with the major version of 8.
System props are style functions that provide one or more props, and can be passed directly the return value of [styled-components]'s styled()
function:
import {styled} from 'styled-components'
import {space} from 'styled-system'
const SpaceDiv = styled.div`
${space}
`