hex-to-array-buffer/index.js

Turn a string of hexadecimal characters into an `ArrayBuffer`.

export default function hexToArrayBuffer (input) {
  if (typeof input !== 'string') {
    throw new TypeError('Expected input to be a string')
  }

  if ((input.length % 2) !== 0) {
    throw new RangeError('Expected string to be an even number of characters')
  }

  const view = new Uint8Array(input.length / 2)

  for (let i = 0; i < input.length; i += 2) {
    view[i / 2] = parseInt(input.substring(i, i + 2), 16)
  }

  return view.buffer
}