make this a proper esm module

bin/server.cjs

@@ -0,0 +1,36 @@
+#!/usr/bin/env node
+
+/**
+ * @type {any}
+ */
+const WebSocket = require('ws')
+const http = require('http')
+const number = require('lib0/number')
+const wss = new WebSocket.Server({ noServer: true })
+const setupWSConnection = require('./utils.cjs').setupWSConnection
+
+const host = process.env.HOST || 'localhost'
+const port = number.parseInt(process.env.PORT || '1234')
+
+const server = http.createServer((_request, response) => {
+  response.writeHead(200, { 'Content-Type': 'text/plain' })
+  response.end('okay')
+})
+
+wss.on('connection', setupWSConnection)
+
+server.on('upgrade', (request, socket, head) => {
+  // You may check auth of request here..
+  // See https://github.com/websockets/ws#client-authentication
+  /**
+   * @param {any} ws
+   */
+  const handleAuth = ws => {
+    wss.emit('connection', ws, request)
+  }
+  wss.handleUpgrade(request, socket, head, handleAuth)
+})
+
+server.listen(port, host, () => {
+  console.log(`running at '${host}' on port ${port}`)
+})