PostCSS JS

PostCSS for CSS-in-JS and styles in JS objects.

For example, to use Stylelint or RTLCSS plugins in your workflow.

---

PostCSS JS Parser is built by Evil Martians, an American design and engineering consultancy for developer tools, AI, and cybersecurity startups.

---

Usage

Processing

constpostcssJs=require('postcss-js')constautoprefixer=require('autoprefixer')constprefixer=postcssJs.sync([autoprefixer])conststyle=prefixer({userSelect: 'none'})style//=> {// WebkitUserSelect: 'none',// MozUserSelect: 'none',// msUserSelect: 'none',// userSelect: 'none'// }

Compile CSS-in-JS to CSS

constpostcss=require('postcss')constpostcssJs=require('postcss-js')conststyle={'top': 10,'&:hover': {top: 5}}postcss().process(style,{parser: postcssJs}).then(result=>{result.css//=> top: 10px;// &:hover { top: 5px; }})

Compile CSS to CSS-in-JS

constpostcss=require('postcss')constpostcssJs=require('postcss-js')constcss='--text-color: #DD3A0A; @media screen { z-index: 1; color: var(--text-color) }'constroot=postcss.parse(css)postcssJs.objectify(root)//=> {// '--text-color': '#DD3A0A',// '@media screen': {// zIndex: '1',// color: 'var(--text-color)'// }// }

API

sync(plugins): function

Create PostCSS processor with simple API, but with only sync PostCSS plugins support.

Processor is just a function, which takes one style object and return other.

async(plugins): function

Same as sync, but also support async plugins.

Returned processor will return Promise.

parse(obj): Root

Parse CSS-in-JS style object to PostCSS Root instance.

It converts numbers to pixels and parses [Free Style] like selectors and at-rules:

{'@media screen': {'&:hover': {top: 10}}}

This methods use Custom Syntax name convention, so you can use it like this:

postcss().process(obj,{parser: postcssJs})

objectify(root): object

Convert PostCSS Root instance to CSS-in-JS style object.

Troubleshoot

Webpack may need some extra config for some PostCSS plugins.

Module parse failed

Autoprefixer and some other plugins need a json-loader to import data.

So, please install this loader and add to webpack config:

loaders: [{test: /\.json$/,loader: 'json-loader'}]