Developer guide

For basics see How to contribute.

Styleguidist isn’t an ordinary single-page app and some design decisions may look confusing to an outsider. In this guide, we’ll explain these decisions to un-confuse potential contributors.

The main thing is that we’re running two apps at the same time: user’s components and Styleguidist UI. They share a webpack configuration and have styles in the same scope (there’s only one scope in CSS). And we can control only one of these two apps: Styleguidist UI. That puts us under some restrictions:

  • Our styles should not affect user component styles.
  • User styles (especially global like Bootstrap) should not affect Styleguidist UI.
  • body styles (like font-family) should affect user components as the user expects but not Styleguidist UI.

How it works

Styleguidist uses react-docgen to parse source files (not transpiled). react-docgen finds exported React components and generates documentation based on PropTypes or Flow annotations.

Styleguidist uses Markdown for documentation: each JavaScript code block is rendered as an interactive playground with react-simple-code-editor. To do that we extract all these code blocks using Remark.

Webpack loaders (see below) generate JavaScript modules with all user components, their documentation and examples and pass that to a React app which renders a style guide.

Webpack loaders and webpack configuration

We use webpack loaders to hot reload the style guide on changes in user components, styles and Markdown documentation. We have three loaders (loaders folder):

  • styleguide-loader: loads components and sections;
  • props-loaders: loads props documentation using react-docgen;
  • examples-loader: loads examples from Markdown files;

Styleguidist tries to load and reuse the user’s webpack config (webpack.config.js in project root folder). It works most of the time but has some restrictions: Styleguidist ignores some fields and plugins because they are already included (like webpack.HotModuleReplacementPlugin), don’t make sense for a style guide (like output) or may break Styleguidist (like entry).

We’re trying to keep Styleguidist’s webpack config minimal to reduce clashes with the user’s configuration.

React components

Most of StyleGuidist UI components consist of two parts: Foo/Foo.js that contains all logic and Foo/FooRenderer.js that contains all markup and styles. This allows users to customize rendering by overriding *Renderer component using webpack aliases (or styleguideComponents config option):

// styleguide.config.js
const path = require('path')
module.exports = {
webpackConfig: {
resolve: {
alias: {
'rsg-components/Wrapper': path.join(
__dirname,
'lib/styleguide/Wrapper'
)
}
}
}
}

All Styleguidist components should be imported like this: import Foo from 'rsg-components/Foo' to make aliases work.

Each component folder usually has several files:

  • Foo/Foo.js (optional for basic components);
  • Foo/FooRenderer.js;
  • Foo/Foo.spec.js — tests;
  • Foo/index.js — reexport of Foo.js or FooRenderer.js.

Styles

For styles we use JSS, it allows users to customize their style guide and allows us to ensure style isolation (thanks to jss-isolate). No user styles should affect Styleguidist UI and no Styleguidist styles should affect user components.

Use clsx to merge several class names or for conditional class names, import it as cx (import cx from 'clsx').

We use Styled higher-order component to allow theming (see theme and style style guide config options). Use it like this:

import React from 'react'
import Styled from 'rsg-components/Styled'
export const styles = ({ fontFamily, fontSize, color }) => ({
button: {
fontSize: fontSize.base,
fontFamily: fontFamily.base,
color: color.light,
'&:hover, &:active': {
isolate: false,
color: color.lightest
}
}
})
function ExamplePlaceholderRenderer({ classes }) {
return (
<button className={classes.button}>I am a styled button</button>
)
}
export default Styled(styles)(ExamplePlaceholderRenderer)

Check available theme variables in src/client/styles/theme.js.

Because of isolation and theming you need to explicitly declare fontFamily, fontSize and color. Add isolate: false to your hover styles, otherwise you’ll have to repeat base non-hover styles.

Testing

We’re using Jest with React Test Renderer for testing. Put your component tests into Component.spec.js file in the same folder and all other tests into __tests__/filename.spec.js.

To test particular class names use classes function (available in the global namespace in tests):

import { TabButtonRenderer, styles } from './TabButtonRenderer'
const props = {
classes: classes(styles)
}
it('should render active styles', () => {
const renderer = createRenderer()
renderer.render(
<TabButtonRenderer {...props} active>
pizza
</TabButtonRenderer>
)
expect(actual.toJson()).toMatchSnapshot()
})