use camelcase file names from now on...

src/events/login.ts

@@ -0,0 +1,9 @@
+import { Server } from 'socket.io'
+import { TSocket } from '../utilities/types'
+
+export default function (socket: TSocket, io: Server) {
+  socket.on('login', () => {
+    // return user data
+    socket.emit('logged_in', { user: socket.user })
+  })
+}