negativeMargin.js

import _ from 'lodash'

export default function() {
  return function({ addUtilities, e, config }) {
    const generators = [
      (size, modifier) => ({
        [`.${e(`-m-${modifier}`)}`]: { margin: `${size}` },
      }),
      (size, modifier) => ({
        [`.${e(`-my-${modifier}`)}`]: { 'margin-top': `${size}`, 'margin-bottom': `${size}` },
        [`.${e(`-mx-${modifier}`)}`]: { 'margin-left': `${size}`, 'margin-right': `${size}` },
      }),
      (size, modifier) => ({
        [`.${e(`-mt-${modifier}`)}`]: { 'margin-top': `${size}` },
        [`.${e(`-mr-${modifier}`)}`]: { 'margin-right': `${size}` },
        [`.${e(`-mb-${modifier}`)}`]: { 'margin-bottom': `${size}` },
        [`.${e(`-ml-${modifier}`)}`]: { 'margin-left': `${size}` },
      }),
    ]

    const utilities = _.flatMap(generators, generator => {
      return _.flatMap(config('theme.negativeMargin'), (size, modifier) => {
        return generator(`${size}` === '0' ? `${size}` : `-${size}`, modifier)
      })
    })

    addUtilities(utilities, config('variants.negativeMargin'))
  }
}