UMD for asynchronously generating a deobfuscation effect with customizable attributes

deobfuscate.js

((root, factory) => {
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    define([], factory)
  } else if (typeof module === 'object' && module.exports) {
    // Node. Does not work with strict CommonJS.
    module.exports = factory()
  } else {
    // Browser globals (root is window)
    root.deobfuscate = factory()
  }
})(typeof self !== 'undefined' ? self : this, () => {
  const delay = ms => new Promise(resolve => { setTimeout(resolve, ms) })
  const range = (begin, end) => [...Array(1 + end - begin).keys()].map(index => begin + index)
  const toCharCode = (...string) => string.map(char => char.charCodeAt(0))
  const charRange = (begin, end) => String.fromCharCode(...range(...toCharCode(begin, end)))
  const choose = array => array[Math.floor(Math.random() * array.length)]
  const lookup = o => key => o[key]

  // Just return a value to define the module export.
  return async ({
    string = '',
    duration = 1,
    fps = 60,
    random = charRange('\u0020', '\u007e'),
    next = choose,
    render
  } = {}) => {
    const { length } = string
    const getters = Array(length).fill(() => choose(random))
    const obfuscated = [...getters.keys()]
    const timeout = duration * 1000 / length
    const charAt = lookup(string)
    const interval = setInterval(() => {
      render(getters.map((getter, index) => getter(index)).join(''), false)
    }, 1000 / fps)

    let indices = Object.values(obfuscated)

    while (indices.length > 0) {
      await delay(timeout)
      const index = next(indices)
      getters[index] = charAt
      delete obfuscated[index]
      indices = Object.values(obfuscated)
    }

    clearInterval(interval)
    render(string)
  }
})