Function prepareRequestHeadersArray

lib/internal/http2/util.js:621–704

* Takes a request headers array, validates it and sets defaults, and returns * the resulting headers in NgHeaders string list format. * @returns {object}

(headers, session)

 * @returns {object}
 */
function prepareRequestHeadersArray(headers, session) {
  let method;
  let scheme;
  let authority;
  let path;
  let protocol;

  // Extract the key pseudo header values from the headers array.
  for (let i = 0; i < headers.length; i += 2) {
    if (headers[i][0] !== ':') {
      continue;
    }

    const header = headers[i].toLowerCase();
    const value = headers[i + 1];

    if (header === HTTP2_HEADER_METHOD) {
      method = value;
    } else if (header === HTTP2_HEADER_SCHEME) {
      scheme = value;
    } else if (header === HTTP2_HEADER_AUTHORITY) {
      authority = value;
    } else if (header === HTTP2_HEADER_PATH) {
      path = value;
    } else if (header === HTTP2_HEADER_PROTOCOL) {
      protocol = value;
    }
  }

  // We then build an array of any missing pseudo headers, to prepend
  // default values to the given header array:
  const additionalPseudoHeaders = [];

  if (method === undefined) {
    method = HTTP2_METHOD_GET;
    additionalPseudoHeaders.push(HTTP2_HEADER_METHOD, method);
  }

  const connect = method === HTTP2_METHOD_CONNECT;

  if (!connect || protocol !== undefined) {
    if (authority === undefined && headers[HTTP2_HEADER_HOST] === undefined) {
      authority = session[kAuthority];
      additionalPseudoHeaders.push(HTTP2_HEADER_AUTHORITY, authority);
    }
    if (scheme === undefined) {
      scheme = session[kProtocol].slice(0, -1);
      additionalPseudoHeaders.push(HTTP2_HEADER_SCHEME, scheme);
    }
    if (path === undefined) {
      additionalPseudoHeaders.push(HTTP2_HEADER_PATH, '/');
    }
  } else {
    if (authority === undefined)
      throw new ERR_HTTP2_CONNECT_AUTHORITY();
    if (scheme !== undefined)
      throw new ERR_HTTP2_CONNECT_SCHEME();
    if (path !== undefined)