ES6: custom webfont loader promise

webFontLoader.js

// families: array
// urls: array
export async function customWebFontLoader({ families, urls }) {
  return new Promise((resolve, reject) => {
    WebFont.load({
      custom: {
        families,
        urls,
      },
      active: () => {
        resolve()
      },
      inactive: () => {
        reject()
      },
    })
  })
}