Webpack: load Intl polyfill with languages

polyfill-intl.js

const needsPolyfill = !window.Intl

/* eslint-disable import/no-webpack-loader-syntax */
const intl = require('bundle-loader?lazy&name=intl!intl')
/* eslint-enable import/no-webpack-loader-syntax */
const polyfilled = needsPolyfill && new Promise(resolve => {
  intl(resolve)
})

export default Promise.all([ polyfilled ])

// see https://webpack.js.org/loaders/bundle-loader/
// we have to statically reference each language file so that webpack can resolve them at build time
// see https://github.com/andyearnshaw/Intl.js/tree/master/locale-data/jsonp
const load = {
  /* eslint-disable import/no-webpack-loader-syntax */
  'de': require('bundle-loader?lazy&name=intl-de!intl/locale-data/jsonp/de.js'),
  'el': require('bundle-loader?lazy&name=intl-el!intl/locale-data/jsonp/el.js'),
  'en-US': require('bundle-loader?lazy&name=intl-en-US!intl/locale-data/jsonp/en-US.js'),
  'en': require('bundle-loader?lazy&name=intl-en!intl/locale-data/jsonp/en-GB.js'),
  'fi': require('bundle-loader?lazy&name=intl-fi!intl/locale-data/jsonp/fi.js'),
  'hr': require('bundle-loader?lazy&name=intl-hr!intl/locale-data/jsonp/hr.js'),
  'it': require('bundle-loader?lazy&name=intl-it!intl/locale-data/jsonp/it.js'),
  'nb-NO': require('bundle-loader?lazy&name=intl-nb-NO!intl/locale-data/jsonp/nb-NO.js'),
  'nl-NL': require('bundle-loader?lazy&name=intl-nl-NL!intl/locale-data/jsonp/nl-NL.js'),
  'nn': require('bundle-loader?lazy&name=intl-nn!intl/locale-data/jsonp/nn.js'),
  'sk': require('bundle-loader?lazy&name=intl-sk!intl/locale-data/jsonp/sk.js'),
  /* eslint-enable import/no-webpack-loader-syntax */
}

export function loadIntlLocale (locale) {
  if (!needsPolyfill) {
    return Promise.resolve()
  }

  return polyfilled.then(() => {
    return new Promise((resolve, reject) => {
      const loader = load[locale]
      if (!loader) {
        reject(new Error(`Intl locale "${locale}" not registered`))
      }

      loader(resolve)
    })
  })
}