Function removeChars

deps/undici/src/lib/web/fetch/formdata-parser.js:492–505

* @param {Buffer} buf * @param {boolean} leading * @param {boolean} trailing * @param {(charCode: number) => boolean} predicate * @returns {Buffer}

(buf, leading, trailing, predicate)

 * @returns {Buffer}
 */
function removeChars (buf, leading, trailing, predicate) {
  let lead = 0
  let trail = buf.length - 1

  if (leading) {
    while (lead < buf.length && predicate(buf[lead])) lead++
  }

  if (trailing) {
    while (trail > 0 && predicate(buf[trail])) trail--
  }

  return lead === 0 && trail === buf.length - 1 ? buf : buf.subarray(lead, trail + 1)
}

/**
 * Checks if {@param buffer} starts with {@param start}