@reduxjs/toolkit/src/entities/state_selectors.test.ts

The official, opinionated, batteries-included toolset for efficient Redux development

import { createEntityAdapter, EntityAdapter, EntityState } from './index'
import { EntitySelectors } from './models'
import {
  BookModel,
  AClockworkOrange,
  AnimalFarm,
  TheGreatGatsby
} from './fixtures/book'
import { createSelector, Selector } from 'reselect'

describe('Entity State Selectors', () => {
  describe('Composed Selectors', () => {
    interface State {
      books: EntityState<BookModel>
    }

    let adapter: EntityAdapter<BookModel>
    let selectors: EntitySelectors<BookModel, State>
    let state: State

    beforeEach(() => {
      adapter = createEntityAdapter({
        selectId: (book: BookModel) => book.id
      })

      state = {
        books: adapter.setAll(adapter.getInitialState(), [
          AClockworkOrange,
          AnimalFarm,
          TheGreatGatsby
        ])
      }

      selectors = adapter.getSelectors((state: State) => state.books)
    })

    it('should create a selector for selecting the ids', () => {
      const ids = selectors.selectIds(state)

      expect(ids).toEqual(state.books.ids)
    })

    it('should create a selector for selecting the entities', () => {
      const entities = selectors.selectEntities(state)

      expect(entities).toEqual(state.books.entities)
    })

    it('should create a selector for selecting the list of models', () => {
      const models = selectors.selectAll(state)

      expect(models).toEqual([AClockworkOrange, AnimalFarm, TheGreatGatsby])
    })

    it('should create a selector for selecting the count of models', () => {
      const total = selectors.selectTotal(state)

      expect(total).toEqual(3)
    })

    it('should create a selector for selecting a single item by ID', () => {
      const first = selectors.selectById(state, AClockworkOrange.id)
      expect(first).toBe(AClockworkOrange)
      const second = selectors.selectById(state, AnimalFarm.id)
      expect(second).toBe(AnimalFarm)
    })
  })

  describe('Uncomposed Selectors', () => {
    type State = EntityState<BookModel>

    let adapter: EntityAdapter<BookModel>
    let selectors: EntitySelectors<BookModel, EntityState<BookModel>>
    let state: State

    beforeEach(() => {
      adapter = createEntityAdapter({
        selectId: (book: BookModel) => book.id
      })

      state = adapter.setAll(adapter.getInitialState(), [
        AClockworkOrange,
        AnimalFarm,
        TheGreatGatsby
      ])

      selectors = adapter.getSelectors()
    })

    it('should create a selector for selecting the ids', () => {
      const ids = selectors.selectIds(state)

      expect(ids).toEqual(state.ids)
    })

    it('should create a selector for selecting the entities', () => {
      const entities = selectors.selectEntities(state)

      expect(entities).toEqual(state.entities)
    })

    it('should type single entity from Dictionary as entity type or undefined', () => {
      const singleEntity: Selector<
        EntityState<BookModel>,
        BookModel | undefined
      > = createSelector(selectors.selectEntities, entities => entities[0])
    })

    it('should create a selector for selecting the list of models', () => {
      const models = selectors.selectAll(state)

      expect(models).toEqual([AClockworkOrange, AnimalFarm, TheGreatGatsby])
    })

    it('should create a selector for selecting the count of models', () => {
      const total = selectors.selectTotal(state)

      expect(total).toEqual(3)
    })

    it('should create a selector for selecting a single item by ID', () => {
      const first = selectors.selectById(state, AClockworkOrange.id)
      expect(first).toBe(AClockworkOrange)
      const second = selectors.selectById(state, AnimalFarm.id)
      expect(second).toBe(AnimalFarm)
    })
  })
})