redux-devtools/packages/redux-devtools-cli/src/index.ts

import express from 'express';
import http from 'http';
import getPort from 'get-port';
import socketClusterServer from 'socketcluster-server';
import getOptions from './options';
import routes from './routes';
import createStore from './store';

// const LOG_LEVEL_NONE = 0;
// const LOG_LEVEL_ERROR = 1;
const LOG_LEVEL_WARN = 2;
const LOG_LEVEL_INFO = 3;

export default async function (argv: { [arg: string]: any }): Promise<{
  portAlreadyUsed?: boolean;
  listener: (eventName: 'ready') => { once(): Promise<void> };
}> {
  const options = Object.assign(getOptions(argv), {
    allowClientPublish: false,
  });
  const port = options.port;
  const logLevel =
    options.logLevel === undefined ? LOG_LEVEL_INFO : options.logLevel;
  // Check port already used
  const p = await getPort({ port });
  if (port !== p) {
    if (logLevel >= LOG_LEVEL_WARN) {
      console.log(`[ReduxDevTools] Server port ${port} is already used.`);
    }
    return {
      portAlreadyUsed: true,
      listener: function () {
        return {
          once() {
            return Promise.resolve();
          },
        };
      },
    };
  }

  if (logLevel >= LOG_LEVEL_INFO) {
    console.log('[ReduxDevTools] Start server...');
    console.log('-'.repeat(80) + '\n');
  }
  const httpServer = http.createServer();
  const agServer = socketClusterServer.attach(httpServer, options);

  const app = express();
  httpServer.on('request', app);
  const store = createStore(options);
  app.use(routes(options, store, agServer));

  agServer.setMiddleware(
    agServer.MIDDLEWARE_INBOUND,
    // eslint-disable-next-line @typescript-eslint/no-misused-promises
    async (middlewareStream) => {
      for await (const action of middlewareStream) {
        if (action.type === action.TRANSMIT) {
          const channel = action.receiver;
          const data = action.data;
          if (
            channel.substring(0, 3) === 'sc-' ||
            channel === 'respond' ||
            channel === 'log'
          ) {
            void agServer.exchange.transmitPublish(channel, data);
          } else if (channel === 'log-noid') {
            void agServer.exchange.transmitPublish('log', {
              id: action.socket.id,
              data: data,
            });
          }
        } else if (action.type === action.SUBSCRIBE) {
          if (action.channel === 'report') {
            store
              .list()
              .then(function (data) {
                void agServer.exchange.transmitPublish('report', {
                  type: 'list',
                  data: data,
                });
              })
              .catch(function (error) {
                console.error(error); // eslint-disable-line no-console
              });
          }
        }
        action.allow();
      }
    }
  );

  void (async () => {
    for await (const { socket } of agServer.listener('connection')) {
      let channelToWatch: string, channelToEmit: string;
      void (async () => {
        for await (const request of socket.procedure('login')) {
          const credentials = request.data;
          if (credentials === 'master') {
            channelToWatch = 'respond';
            channelToEmit = 'log';
          } else {
            channelToWatch = 'log';
            channelToEmit = 'respond';
          }
          request.end(channelToWatch);
        }
      })();
      void (async () => {
        for await (const request of socket.procedure('getReport')) {
          const id = request.data as string;
          store
            .get(id)
            .then(function (data) {
              request.end(data);
            })
            .catch(function (error) {
              console.error(error); // eslint-disable-line no-console
            });
        }
      })();
      void (async () => {
        for await (const data of socket.listener('disconnect')) {
          const channel = agServer.exchange.channel('sc-' + socket.id);
          channel.unsubscribe();
          // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
          void agServer.exchange.transmitPublish(channelToEmit!, {
            id: socket.id,
            type: 'DISCONNECTED',
          });
        }
      })();
    }
  })();

  httpServer.listen(options.port);
  // @ts-expect-error Shouldn't there be a 'ready' event?
  return agServer;
}