@jeremyckahn/farmhand/src/game-logic/reducers/processCowBreeding.test.ts

A farming game

import {
  EXPERIENCE_VALUES,
  COW_GESTATION_PERIOD_DAYS,
  PURCHASEABLE_COW_PENS,
} from '../../constants.js'
import { genders } from '../../enums.js'
import { generateCow } from '../../utils/index.js'
import { testState } from '../../test-utils/index.js'

import { processCowBreeding } from './processCowBreeding.js'

describe('processCowBreeding', () => {
  const maleCow1 = generateCow({ gender: genders.MALE, happiness: 1 })
  const maleCow2 = generateCow({ gender: genders.MALE, happiness: 1 })
  const femaleCow = generateCow({ gender: genders.FEMALE, happiness: 1 })

  describe('there are less than two cows in breeding pen', () => {
    test('no-ops', () => {
      const inputState = testState({
        cowBreedingPen: {
          cowId1: maleCow1.id,
          cowId2: null,
          daysUntilBirth: COW_GESTATION_PERIOD_DAYS,
        },
        cowInventory: [maleCow1],
        newDayNotifications: [],
        purchasedCowPen: 1,
      })

      const state = processCowBreeding(inputState)

      expect(state).toBe(inputState)
    })
  })

  describe('there are two cows in breeding pen', () => {
    describe('cows are same gender', () => {
      test('no-ops', () => {
        const inputState = testState({
          cowBreedingPen: {
            cowId1: maleCow1.id,
            cowId2: maleCow2.id,
            daysUntilBirth: COW_GESTATION_PERIOD_DAYS,
          },
          cowInventory: [maleCow1, maleCow2],
          newDayNotifications: [],
          purchasedCowPen: 1,
        })

        const state = processCowBreeding(inputState)

        expect(state).toBe(inputState)
      })
    })

    describe('cows are opposite gender', () => {
      describe('at least one cow does not meet happiness requirement', () => {
        test('resets daysUntilBirth', () => {
          const {
            cowBreedingPen: { daysUntilBirth },
          } = processCowBreeding(
            testState({
              cowBreedingPen: {
                cowId1: maleCow1.id,
                cowId2: femaleCow.id,
                daysUntilBirth: COW_GESTATION_PERIOD_DAYS - 1,
              },
              cowInventory: [
                generateCow({ ...maleCow1, happiness: 0 }),
                femaleCow,
              ],
              newDayNotifications: [],
              purchasedCowPen: 1,
            })
          )

          expect(daysUntilBirth).toEqual(COW_GESTATION_PERIOD_DAYS)
        })
      })

      describe('both cows meet happiness requirement', () => {
        describe('daysUntilBirth > 1', () => {
          test('decrements daysUntilBirth', () => {
            const {
              cowBreedingPen: { daysUntilBirth },
            } = processCowBreeding(
              testState({
                cowBreedingPen: {
                  cowId1: maleCow1.id,
                  cowId2: femaleCow.id,
                  daysUntilBirth: COW_GESTATION_PERIOD_DAYS,
                },
                cowInventory: [maleCow1, femaleCow],
                newDayNotifications: [],
                purchasedCowPen: 1,
              })
            )

            expect(daysUntilBirth).toEqual(COW_GESTATION_PERIOD_DAYS - 1)
          })
        })

        describe('daysUntilBirth === 1', () => {
          describe('there is space in cowInventory', () => {
            let newState

            beforeEach(() => {
              newState = processCowBreeding(
                testState({
                  cowBreedingPen: {
                    cowId1: maleCow1.id,
                    cowId2: femaleCow.id,
                    daysUntilBirth: 1,
                  },
                  cowInventory: [maleCow1, femaleCow],
                  experience: 0,
                  newDayNotifications: [],
                  purchasedCowPen: 1,
                })
              )
            })

            test('adds offspring cow to cowInventory', () => {
              expect(newState.cowInventory).toHaveLength(3)
            })

            test('adds experience', () => {
              expect(newState.experience).toEqual(EXPERIENCE_VALUES.COW_BRED)
            })
          })

          describe('there is no space in cowInventory', () => {
            test('offspring cow is not added to cowInventory', () => {
              const { cowInventory } = processCowBreeding(
                testState({
                  cowBreedingPen: {
                    cowId1: maleCow1.id,
                    cowId2: femaleCow.id,
                    daysUntilBirth: 1,
                  },
                  cowInventory: [
                    maleCow1,
                    femaleCow,
                    ...new Array(
                      (PURCHASEABLE_COW_PENS.get(1) || { cows: 10 }).cows - 2
                    )
                      .fill(null)
                      .map(() => generateCow()),
                  ],
                  newDayNotifications: [],
                  purchasedCowPen: 1,
                })
              )

              expect(cowInventory).toHaveLength(
                (PURCHASEABLE_COW_PENS.get(1) || { cows: 10 }).cows
              )
            })
          })

          test('resets daysUntilBirth', () => {
            const {
              cowBreedingPen: { daysUntilBirth },
            } = processCowBreeding(
              testState({
                cowBreedingPen: {
                  cowId1: maleCow1.id,
                  cowId2: femaleCow.id,
                  daysUntilBirth: 1,
                },
                cowInventory: [maleCow1, femaleCow],
                newDayNotifications: [],
                purchasedCowPen: 1,
              })
            )

            expect(daysUntilBirth).toEqual(COW_GESTATION_PERIOD_DAYS)
          })
        })
      })
    })
  })
})