const $users = createStore({})

​

const {addUser, removeUser} = createApi($users, {

  addUser: (state, {id, value}) => ({

    ...state,

    [id]: {id, value},

  }),

  removeUser: (state, id) => {

    const {[id]: _, ...rest} = state

    return rest

  },

})

​

const getUserValue = (id) => {

  const $user = $users.map(users => users[id] ?? null)

  const $computedUser = $user.map(user => {

    if (user === null) return null

    console.log('compute user', user.id)

    return { ...user, value: user.value + 25 }

  })

  return $computedUser

}

​

$users.watch(users => console.log('users', users))

getUserValue(1).watch(user => console.log('user 1', user))

getUserValue(2).watch(user => console.log('user 2', user))

​

addUser({id: 1, value: 10})

addUser({id: 2, value: 12})

removeUser(2)

​