headers.ts

export function encodeHeaderValue(value: string): string {
  // encodeURIComponent escapes the following chars which are allowed
  // in header values.
  // : ; , / " ? { } [ ] @ < > = + # $ & ` | ^ space and %
  // Unescape all of them expect %, to make the encoded value smaller and more
  // readable.  Do not unescape % as that would break decoding of the
  // percent decoding done by encodeURIComponent.
  return encodeURIComponent(value).replace(
    /%(3A|3B|2C|2F|22|3F|7B|7D|5B|5D|40|3C|3E|3D|2B|23|24|26|60|7C|5E|20)/g,
    (_, hex) => String.fromCharCode(parseInt(hex, 16)),
  );
}

export function decodeHeaderValue(encoded: string): string {
  return decodeURIComponent(encoded);
}