timing-provider-server/build/node/app.js

A command line tool to spin up a server which can be used with the timing-provider.

#!/usr/bin/env node
import { argv } from 'process';
import { generateUniqueNumber } from 'fast-unique-numbers';
import { WebSocketServer } from 'ws';
import yargs from 'yargs';
const commandLineArguments = yargs(argv.slice(2)).help().option('port', {
  default: 2276,
  describe: 'specify the port at which the server will be listening',
  type: 'number'
}).strict().argv;
if (commandLineArguments instanceof Promise) {
  throw new TypeError('The command line arguments are expected to get parsed synchronously.');
}
const {
  port
} = commandLineArguments;
const activeConnections = new Map();
const server = new WebSocketServer({
  port
});
let origin = 0;
server.on('connection', connection => {
  const id = generateUniqueNumber(activeConnections);
  const sendMessage = message => connection.send(JSON.stringify(message));
  activeConnections.set(id, sendMessage);
  sendMessage({
    client: {
      id
    },
    events: [],
    origin,
    type: 'init'
  });
  origin += 1;
  connection.on('message', message => {
    const parsedMessage = JSON.parse(message.toString());
    const sendMessageToActiveConnection = activeConnections.get(parsedMessage.client.id);
    if (sendMessageToActiveConnection === undefined) {
      sendMessage({
        client: parsedMessage.client,
        type: 'termination'
      });
    } else if (parsedMessage.type !== 'check') {
      sendMessageToActiveConnection({
        ...parsedMessage,
        client: {
          id
        }
      });
    }
  });
  connection.on('close', () => activeConnections.delete(id));
  for (const [clientIdOfActiveConnection, sendMessageToActiveConnection] of activeConnections) {
    if (clientIdOfActiveConnection !== id) {
      const ids = [id, clientIdOfActiveConnection].sort();
      const label = ids.join('-');
      const type = 'request';
      if (ids[0] === id) {
        sendMessage({
          client: {
            id: clientIdOfActiveConnection
          },
          label,
          type
        });
      } else {
        sendMessageToActiveConnection({
          client: {
            id
          },
          label,
          type
        });
      }
    }
  }
});