frontend/node_modules/autoprefixer/lib/hacks/flex-spec.js

/**
 * Return flexbox spec versions by prefix
 */
module.exports = function (prefix) {
  let spec
  if (prefix === '-webkit- 2009' || prefix === '-moz-') {
    spec = 2009
  } else if (prefix === '-ms-') {
    spec = 2012
  } else if (prefix === '-webkit-') {
    spec = 'final'
  }

  if (prefix === '-webkit- 2009') {
    prefix = '-webkit-'
  }

  return [spec, prefix]
}