const user = (state = [], action) => {
  switch (action.type) {
  case "ADD_USERS":
    return action.users
  case "UPDATE_USER":
    const { userToken, newAttributes } = action
    return state.map(user => {
      return (user.token === userToken) ? { ...user, ...newAttributes } : user
    })
  default:
    return state
  }
}

export default user

const user = (state = [], action) => {
  switch (action.type) {
    case "ADD_USERS":
      return action.users
    case "UPDATE_USER":
      const { userToken, newAttributes } = action
      return state.map(user => {
        return (user.token === userToken) ? { ...user, ...newAttributes } : user
      })
    default:
      return state
  }
}

export default user

Fix indentation in user reducer