Function parseMultipartFormDataHeaders

lib/web/fetch/formdata-parser.js:315–468

* @see https://andreubotella.github.io/multipart-form-data/#parse-multipart-form-data-headers * @param {Buffer} input * @param {{ position: number }} position

(input, position)

 * @param {{ position: number }} position
 */
function parseMultipartFormDataHeaders (input, position) {
  // 1. Let name, filename and contentType be null.
  let name = null
  let filename = null
  let contentType = null
  let encoding = null

  // 2. While true:
  while (true) {
    // 2.1. If position points to a sequence of bytes starting with 0x0D 0x0A (CR LF):
    if (input[position.position] === 0x0d && input[position.position + 1] === 0x0a) {
      // 2.1.1. If name is null, return failure.
      if (name === null) {
        throw parsingError('header name is null')
      }

      // 2.1.2. Return name, filename and contentType.
      return { name, filename, contentType, encoding }
    }

    // 2.2. Let header name be the result of collecting a sequence of bytes that are
    //      not 0x0A (LF), 0x0D (CR) or 0x3A (:), given position.
    let headerName = collectASequenceOfBytes(
      (char) => char !== 0x0a && char !== 0x0d && char !== 0x3a,
      input,
      position
    )

    // 2.3. Remove any HTTP tab or space bytes from the start or end of header name.
    headerName = removeChars(headerName, true, true, (char) => char === 0x9 || char === 0x20)

    // 2.4. If header name does not match the field-name token production, return failure.
    if (!HTTP_TOKEN_CODEPOINTS.test(headerName.toString())) {
      throw parsingError('header name does not match the field-name token production')
    }

    // 2.5. If the byte at position is not 0x3A (:), return failure.
    if (input[position.position] !== 0x3a) {
      throw parsingError('expected :')
    }

    // 2.6. Advance position by 1.
    position.position++

    // 2.7. Collect a sequence of bytes that are HTTP tab or space bytes given position.
    //      (Do nothing with those bytes.)
    collectASequenceOfBytes(
      (char) => char === 0x20 || char === 0x09,
      input,
      position
    )

    // 2.8. Byte-lowercase header name and switch on the result:
    switch (bufferToLowerCasedHeaderName(headerName)) {
      case 'content-disposition': {
        name = filename = null
        // Track whether filename was set from the extended (RFC 5987) form so
        // a subsequent legacy `filename` attribute does not override it.