Function replaceInvalidHttpHeaderChar

src/string.ts:82–115

(val: string, replacement?: string | Replacement)

 * @param {String|Function} replacement - can be `function(char)`
 */
export function replaceInvalidHttpHeaderChar(val: string, replacement?: string | Replacement) {
  replacement = replacement || ' ';
  let invalid = false;

  if (!val || typeof val !== 'string') {
    return {
      val,
      invalid,
    };
  }

  let chars: string[] | undefined;
  for (let i = 0; i < val.length; ++i) {
    if (!validHdrChars[val.charCodeAt(i)]) {
      // delay create chars
      chars = chars || val.split('');
      if (typeof replacement === 'function') {
        chars[i] = replacement(chars[i]);
      } else {
        chars[i] = replacement;
      }
    }
  }

  if (chars) {
    val = chars.join('');
    invalid = true;
  }

  return {
    val,
    invalid,
  };
}

/**
 * Detect invalid http header characters in a string