css-razor

css-razor is a fast way to remove unused selectors from css. Essentially, it accomplishes the same goal as uncss. However, it accomplishes this goal differently. Rather than loading a webpage in phantomjs and using document.querySelector to determine if a selector is being used, css-razor uses cheeriojs to parse static html and css files to removed unused selectors.

Helps trim down CSS so you only keep the necessary parts
Built for speed using the amazing cheeriojs
has an ignore list that can be added to
ignores common pseudo elements & pseudo selectors by default
Supports multiple files / globs
Supports raw html & css input
Supports html paths from URLs
Reporting stats detailing how many selectors are removed.

Getting Started

Install with npm

npm install --save-dev css-razor

You can then use the cli

css-razor build/css/index.css build/index.html --stdout > build/css/index.min.css

And you can even pass globs

css-razor build/css/*.css build/*.html --stdout > build/css/index.min.css

Or you can use the js api

const cssRazor = require('css-razor').default

cssRazor({
  html: ['build/index.html'],
  css: ['build/css/index.css'],
}, function(err, data) {
  console.log(data.css)
})

Options

module.exports = {
  // Array of HTML file globs.
  html: [],
  // Array of CSS file globs.
  css: [],
  // Raw HTML string.
  htmlRaw: '',
  // Raw CSS string.
  cssRaw: '',
  // Array of webpages to add to HTML.
  webpages: [],
  // Strings in CSS classes to ignore. Pass `false`
  // (or `--no-ignore` via cli) to not ignore these.
  ignore: [
    'html', // global element
    'body', // global element
    'button', // global element

    'active', // state class
    'inactive', // state class
    'collapsed', // state class
    'expanded', // state class
    'show', // state class
    'hide', // state class
    'hidden', // state class
    'is-', // state class
  ],
  // Where to output
  outputFile: 'dist/index.css',
  // Disable output via stdout w/ `--no-stdout`.
  stdout: false,
  // Report Stats about used vs unused selectors.
  report: false,
  // Detailed Report Stats including every selector used vs unused.
  // Note: this also depends on the `report` option being true.
  reportDetails: false,
  // Overwrite the input css file if there is only one.
  overwriteCss: false,
}

Usage with Postcss

const postcssRazor = require('css-razor').postcss

postcss([
    postcssRazor({
      html: "<html>your html string</html>",
    })
  ])
  .process(css, {
    from: 'index.css',
    to: 'output.css'
  })

React to HTML Example

Below is an example of building an html file from a react app created with create-react-app. The resulting HTML file can then be used for server rendering and detecting selectors with css-razor.

index.js:

import App from './components/App'
import './index.css'

if (typeof window !== 'undefined') { // Web
  ReactDOM.render(
    <App />,
    window.document.getElementById('root')
  )
} else { // Node / server render
  global.appToRender = App
}

buildStatic.js:

const app = global.appToRender
const markup = ReactDOM.renderToString(ReactDOM.createElement(app));

const html = fs.readFileSync(HTML_FILE)
const newHtml = html.toString().split('<div id="root"></div>').join(
  '<div id="root">' + markup + '</div>'
)

fs.writeFileSync(HTML_FILE, newHtml, 'utf8')

Todo

html input via stdin?
more tests for raw and globs
test for postcss plugin usage

tscanlin/css-razor

tscanlin

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