Function parseCacheControlHeader

lib/util/cache.js:314–530

* @see https://www.rfc-editor.org/rfc/rfc9111.html#name-cache-control * @see https://www.iana.org/assignments/http-cache-directives/http-cache-directives.xhtml * @param {string | string[]} header * @returns {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives}

(header)

 * @returns {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives}
 */
function parseCacheControlHeader (header) {
  /**
   * @type {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives}
   */
  const output = {}
  const invalidNumericDirectives = new Set()
  const invalidNoArgumentDirectives = new Set()

  const directives = splitCacheControlHeaderValue(Array.isArray(header) ? header.join(',') : header)

  for (let i = 0; i < directives.length; i++) {
    const directiveRecord = directives[i]
    const directive = directiveRecord.value.toLowerCase()
    const fromMalformedQuote = directiveRecord.fromMalformedQuote
    const keyValueDelimiter = directive.indexOf('=')

    let key
    let value
    let keyHasTrailingWhitespace = false
    let valueHasLeadingWhitespace = false
    if (keyValueDelimiter !== -1) {
      const rawKey = directive.substring(0, keyValueDelimiter)
      const rawValue = directive.substring(keyValueDelimiter + 1)

      keyHasTrailingWhitespace = trimOWSEnd(rawKey) !== rawKey
      valueHasLeadingWhitespace = trimOWSStart(rawValue) !== rawValue
      key = trimOWS(rawKey)
      value = trimOWSStart(rawValue)
    } else {
      key = trimOWS(directive)
    }

    const malformedRestrictiveDirectiveName = getMalformedRestrictiveDirectiveName(key)
    if (malformedRestrictiveDirectiveName !== undefined) {
      output[malformedRestrictiveDirectiveName] = true
      continue
    }

    switch (key) {
      case 'min-fresh':
      case 'max-stale':
      case 'max-age':
      case 's-maxage':
      case 'stale-while-revalidate':
      case 'stale-if-error': {
        if (fromMalformedQuote || invalidNumericDirectives.has(key)) {
          continue
        }

        if (value === undefined || keyHasTrailingWhitespace || valueHasLeadingWhitespace) {
          delete output[key]
          invalidNumericDirectives.add(key)
          markInvalidCacheControlDirective(output, key)
          continue
        }

        if (
          value.length >= 2 &&