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 };