prejss/src/extract-expressions.js

Get the power of PostCSS with plugins in your JSS styles. 🎨 Just put CSS into JS and get it as JSS object.

import guid from './utils/guid'

export default (chunks, ...variables) => {
  let rawStyles
  let expressions = {}

  // Do we have expressions?
  if (chunks.length === 1) {
    rawStyles = chunks[0];
  } else {
    rawStyles = chunks.map((chunk, index) => {
      const variable = variables[index]
      if (typeof variable === 'function') {
        const key = `$^var__${guid()}`
        expressions[key] = variable
        return chunk + key
      } else if (typeof variable === 'string') {
        return chunk + variable
      } else {
        return chunk
      }
    }).join('')
  }

  return { rawStyles, expressions }
}