Function createSocketURL

client-src/index.js:677–763

(parsedURL)

 * @returns {string} socket URL
 */
const createSocketURL = (parsedURL) => {
  let { hostname } = parsedURL;

  // Node.js module parses it as `::`
  // `new URL(urlString, [baseURLString])` parses it as '[::]'
  const isInAddrAny =
    hostname === "0.0.0.0" || hostname === "::" || hostname === "[::]";

  // why do we need this check?
  // hostname n/a for file protocol (example, when using electron, ionic)
  // see: https://github.com/webpack/webpack-dev-server/pull/384
  if (
    isInAddrAny &&
    self.location.hostname &&
    self.location.protocol.indexOf("http") === 0
  ) {
    hostname = self.location.hostname;
  }

  let socketURLProtocol = parsedURL.protocol || self.location.protocol;

  // When https is used in the app, secure web sockets are always necessary because the browser doesn't accept non-secure web sockets.
  if (
    socketURLProtocol === "auto:" ||
    (hostname && isInAddrAny && self.location.protocol === "https:")
  ) {
    socketURLProtocol = self.location.protocol;
  }

  socketURLProtocol = socketURLProtocol.replace(
    /^(?:http|.+-extension|file)/i,
    "ws",
  );

  let socketURLAuth = "";

  // `new URL(urlString, [baseURLstring])` doesn't have `auth` property
  // Parse authentication credentials in case we need them
  if (parsedURL.username) {
    socketURLAuth = parsedURL.username;

    // Since HTTP basic authentication does not allow empty username,
    // we only include password if the username is not empty.
    if (parsedURL.password) {
      // Result: <username>:<password>
      socketURLAuth = socketURLAuth.concat(":", parsedURL.password);
    }
  }

  // In case the host is a raw IPv6 address, it can be enclosed in
  // the brackets as the brackets are needed in the final URL string.
  // Need to remove those as url.format blindly adds its own set of brackets
  // if the host string contains colons. That would lead to non-working
  // double brackets (e.g. [[::]]) host
  //
  // All of these web socket url params are optionally passed in through resourceQuery,
  // so we need to fall back to the default if they are not provided
  const socketURLHostname = (