Function splitDirectives

http/unstable_cache_control.ts:182–204

Split by comma but not inside double-quoted strings, respecting RFC 9110 * §5.6.4 quoted-pairs. Needed for `no-cache` and `private` whose * quoted-string arguments may contain commas; quoted-pair sequences (e.g. * `\"` or `\,`) inside a quoted-string must not toggle the quote state or * trigger

(value: string)

 * `\"` or `\,`) inside a quoted-string must not toggle the quote state or
 * trigger a split. */
function splitDirectives(value: string): string[] {
  // Fast path: no quotes means a simple split is safe.
  if (!value.includes('"')) return value.split(",");

  const parts: string[] = [];
  let start = 0;
  let inQuotes = false;
  for (let i = 0; i < value.length; i++) {
    const c = value.charCodeAt(i);
    if (c === 92 /* \ */ && inQuotes) {
      // Quoted-pair (RFC 9110 §5.6.4): skip the escaped byte so a `\"` is
      // not seen as a closing quote and a `\,` is not seen as a separator.
      i++;
    } else if (c === 34 /* " */) {
      inQuotes = !inQuotes;
    } else if (c === 44 /* , */ && !inQuotes) {
      parts.push(value.slice(start, i));
      start = i + 1;
    }
  }
  parts.push(value.slice(start));
  return parts;
}

/** Parse a comma-separated list of HTTP field names from a directive argument.
 * Strips surrounding double quotes if present and unescapes any quoted-pair