text: const users = [];
  
  const addUser = ({id, name, room}) => {
      name = name.trim().toLowerCase();
      room = room.trim().toLowerCase();
  
      const existingUser = users.find((user) => user.room  === room & user.name === name);
  
      if (existingUser) {
          return {error: 'Username is taken'};
      }
  
      const user = {id, name, room};
  
      users.push(user);
  
      return {user}
  }
  
  const removeUser = (id) => {
      const index = users.findIndex((user) => user.id === id);
  
      if(index !== -1) {
          return users.splice(index, 1)[0];
      }
  }
  
  const getUser = (id) => users.find((user) => user.id === id);
  
  const getUsersInRoom = (room) => users.filter((user) => user.room === room);
  
  module.exports = {addUser, removeUser, getUser, getUsersInRoom};