mickaelw

export class Basket {
  //...
  
  private applyDiscount(totalOfSameBookBorrowed: number, price: number): number {
      switch (totalOfSameBookBorrowed) {
          case 1:
              return price
          case 2:
              return price * (1 - 0.05)
          default:

mickaelw

export class Basket {
  //...
  
  private applyDiscount(totalOfSameBookBorrowed: number, price: number): number {
    return DiscountCalculatorFactory
              .for(totalOfSameBookBorrowed)
              .applyDiscountOn(price)
  }
}

mickaelw

export class DiscountCalculatorFactory {
    static for(numberOfSameBook: number): DiscountCalculator {
        switch (numberOfSameBook) {
            case 1:
                return new NoDiscountCalculator()
            case 2:
                return new TwoSameBooksDiscountCalculator()
            default:
                return new ThreeOrMoreSameBooksDiscountCalculator()
        }

mickaelw

export interface DiscountCalculator {
    applyDiscountOn(price: number): number
}

mickaelw

export class TwoSameTomesDiscountCalculator implements DiscountCalculator {
    private FIVE_PERCENT_DISCOUNT = 1 - 0.05

    applyDiscountOn(price: number): number {
        return price * this.FIVE_PERCENT_DISCOUNT
    }
}

mickaelw

export class ThreeOrMoreSameBooksDiscountCalculator implements DiscountCalculator {
    private TWENTY_FIVE_PERCENT_DISCOUNT = 1 - 0.25

    applyDiscountOn(price: number): number {
        return price * this.TWENTY_FIVE_PERCENT_DISCOUNT
    }
}

mickaelw

export class NoDiscountCalculator implements DiscountCalculator {
    applyDiscountOn(price: number): number {
        return price
    }
}

mickaelw

class PhoneNumbersSaga(eventPublisher: EventPublisher) extends EventListener {
  private var tracker = new PhoneNumberStateTracker

  def handle(phoneNumbers: List[String]): PhoneNumberStateTracker = {
    eventPublisher.publish(AllPhoneNumberListed(phoneNumbers))
    tracker
  }

  override def execute(event: Event): Unit = event match {
    case apnc: AllPhoneNumbersCounted => tracker = PhoneNumberStateTracker(apnc.total, tracker.totalMatchedPhoneNumbers)

mickaelw

describe('Unit | Basket price calculation', () => {
    let basket: Basket
    
    beforeEach(() => basket = new Basket())
    
    it('For an empty basket', () => {
        expect(basket.price).to.equal(0)
    })
    
    describe('Borrowing n different books', () => {

mickaelw

describe('Unit | Caclcule du prix du panier', () => {
    let basket: Basket
    
    beforeEach(() => basket = new Basket())
    
    it('Pour un panier vide', () => {
        expect(basket.price).to.equal(0)
    })
    
    describe('Emprunter n livres différents', () => {