socket.js

/* global __webpack_dev_server_client__ */

import WebSocketClient from "./clients/WebSocketClient.js";
import { log } from "./utils/log.js";

// this WebsocketClient is here as a default fallback, in case the client is not injected
/* eslint-disable camelcase */
const Client =
  // eslint-disable-next-line no-nested-ternary
  typeof __webpack_dev_server_client__ !== "undefined"
    ? typeof __webpack_dev_server_client__.default !== "undefined"
      ? __webpack_dev_server_client__.default
      : __webpack_dev_server_client__
    : WebSocketClient;
/* eslint-enable camelcase */

let retries = 0;
let maxRetries = 10;

// Initialized client is exported so external consumers can utilize the same instance
// It is mutable to enforce singleton
// eslint-disable-next-line import/no-mutable-exports
export let client = null;

let timeout;

/**
 * @param {string} url
 * @param {{ [handler: string]: (data?: any, params?: any) => any }} handlers
 * @param {number} [reconnect]
 */
const socket = function initSocket(url, handlers, reconnect) {
  client = new Client(url);

  client.onOpen(() => {
    retries = 0;

    if (timeout) {
      clearTimeout(timeout);
    }

    if (typeof reconnect !== "undefined") {
      maxRetries = reconnect;
    }
  });

  client.onClose(() => {
    if (retries === 0) {
      handlers.close();
    }

    // Try to reconnect.
    client = null;

    // After 10 retries stop trying, to prevent logspam.
    if (retries < maxRetries) {
      // Exponentially increase timeout to reconnect.
      // Respectfully copied from the package `got`.
      // eslint-disable-next-line no-restricted-properties
      const retryInMs = 1000 * Math.pow(2, retries) + Math.random() * 100;

      retries += 1;

      log.info("Trying to reconnect...");

      timeout = setTimeout(() => {
        socket(url, handlers, reconnect);
      }, retryInMs);
    }
  });

  client.onMessage(
    /**
     * @param {any} data
     */
    (data) => {
      const message = JSON.parse(data);

      if (handlers[message.type]) {
        handlers[message.type](message.data, message.params);
      }
    },
  );
};

export default socket;