@bebraw/linaria

Zero-runtime CSS in JS library.

---

Features

• Write CSS in JS, but with zero runtime, CSS is extracted to CSS files during build
• Familiar CSS syntax with Sass like nesting
• Use dynamic prop based styles with the React bindings, uses CSS variables behind the scenes
• Easily find where the style was defined with CSS sourcemaps
• Lint your CSS in JS with stylelint
• Use JavaScript for logic, no CSS preprocessor needed

Why use Linaria

Installation

npm install linaria

or

yarn add linaria

Setup

Linaria requires webpack to build your CSS. To set up the build, add the webpack loader to your webpack.config.js after babel-loader (if you use it):

module: {
  rules: [
    {
      test: /\.js$/,
      use: [
        { loader: 'babel-loader' },
        {
          loader: 'linaria/loader',
          options: {
            sourceMap: process.env.NODE_ENV !== 'production',
          },
        },
      ],
    },
    {
      test: /\.css$/,
      use: [
        MiniCssExtractPlugin.loader,
        {
          loader: 'css-loader',
          options: {
            sourceMap: process.env.NODE_ENV !== 'production',
          },
        },
      ],
    },
  ],
  plugins: [
    new MiniCssExtractPlugin({
      filename: 'styles.css',
    }),
  ],
},

You also need css-loader and mini-css-extract-plugin in your pipeline. The usage is shown above.

Now, the CSS you write with Linaria will be extracted at build time to the styles.css file. Linaria automatically vendor prefixes and strips whitespace from the CSS.

Linaria integrates with your CSS pipeline, so you can always perform additional operations on the CSS, for example, using postcss plugins such as clean-css to further minify your CSS.

Optionally, add the linaria/babel preset to your Babel configuration at the end of the presets list to avoid errors when importing the components in your server code or tests:

{
  "presets": [
    "@babel/preset-env",
    "@babel/preset-react",
    "linaria/babel"
  ]
}

Syntax

Linaria can be used with any framework, with additional helpers for React. The basic syntax looks like this:

import { css } from 'linaria';
import { modularScale, hiDPI } from 'polished';
import fonts from './fonts';

// Write your styles in `css` tag
const header = css`
  text-transform: uppercase;
  font-family: ${fonts.heading};
  font-size: ${modularScale(2)};

  ${hiDPI(1.5)} {
    font-size: ${modularScale(2.5)};
  }
`;

// Then use it as a class name
<h1 class={header}>Hello world</h1>;

You can use imported variables and functions for logic inside the CSS code. They will be evaluated at build time.

If you're using React, you can use the styled helper, which makes it easy to write React components with dynamic styles with a styled-component like syntax:

import { styled } from 'linaria/react';
import { families, sizes } from './fonts';

// Write your styles in `styled` tag
const Title = styled.h1`
  font-family: ${families.serif};
`;

const Container = styled.div`
  font-size: ${sizes.medium}px;
  color: ${props => props.color};
  border: 1px solid red;

  &:hover {
    border-color: blue;
  }

  ${Title} {
    margin-bottom: 24px;
  }
`;

// Then use the resulting component
<Container color="#333">
  <Title>Hello world</Title>
</Container>;

Dynamic styles will be applied using CSS custom properties (aka CSS variables) and don't require any runtime.

Documentation

• API and usage
  • Client APIs
  • Server APIs
• Configuring Babel
• Dynamic styles with css tag
• Theming
• Critical CSS extraction
• Bundlers integration
  • Webpack
• Linting
• How it works
• Example

Trade-offs

• No IE11 support when using dynamic styles in components with styled, since it uses CSS custom properties

• Dynamic styles are not supported with css tag. See Dynamic styles with css tag for alternative approaches.

• Modules used in the CSS rules cannot have side-effects. For example:

  import { css } from 'linaria';
  import colors from './colors';
  
  const title = css`
    color: ${colors.text};
  `;

  Here, there should be no side-effects in the colors.js file, or any file it imports. We recommend to move helpers and shared configuration to files without any side-effects.

Editor Plugins

VSCode

• Syntax Highlighting and autocompletion - styled-components plugin
• Linting - stylelint plugin

Atom

• Syntax Highlighting and autocompletion - babel grammar

Recommended Libraries

• linaria-jest – Jest testing utilities for Linaria.
• gatsby-plugin-linaria – Gatsby plugin that sets up Babel and webpack configuration for Linaria
• babel-plugin-object-styles-to-template - Babel plugin to write styles in object syntax with linaria
• babel-plugin-css-prop - Babel plugin to use a css prop ala emotion in linaria
• polished.js - A lightweight toolset for writing styles in JavaScript.

Inspiration

• glam
• styled-components
• css-literal-loader

Acknowledgements

This project wouldn't have been possible without the following libraries or the people behind them.

• babel
• stylis.js

Special thanks to @kentcdodds for his babel plugin and @threepointone for his suggestions and encouragement.

Contributors

Thanks goes to these wonderful people (emoji key):

Paweł Trysła 💻 📖 🤔	Satyajit Sahoo 💻 🤔	Michał Pierzchała 💻 📖 🤔	Lucas 📖	Alexey Pronevich 📖	Wojtek Szafraniec 💻	Tushar Sonawane 📖 💡
Ferran Negre 📖	Jakub Beneš 💻 📖	Oscar Busk 🐛 💻	Dawid 💻 📖

This project follows the all-contributors specification. Contributions of any kind welcome!