FruitStand.ts

interface IFruit {
  name: string
  qty: number
  price: number
}

const FruitStand = () => {
  const fruits = new Map<string, IFruit>();

  const addFruit = (name: string, qty: number, price: number) => {
    if(!fruits.has(name)) {
      fruits.set(name, { name, qty, price})
    } else {
      const existFruit = fruits.get(name)
      existFruit.qty += qty
      existFruit.price = price
      console.log(`The fruit ${name} is already in the list. The new quantity is ${existFruit.qty} and the updated price is ${price.toFixed(2)}`)
    }
  }

  const updateQty = (name: string, qty: number) => {
    if(fruits.has(name)) {
      fruits.get(name)!.qty = qty
    } else {
      // Handle fruit not found
      console.log(`The fruit ${name} is not yet on the list. Please add it first.`)
    }
  }

  const calcTotalValue = (): number => {
    const fruitsArray = Array.from(fruits.values());
		const total:number = fruitsArray.reduce((accumulator, { qty, price }) => {
			return accumulator + qty * price
		}, 0)
		return total
  }

  return {
    addFruit,
    updateQty,
    calcTotalValue
  }
}

// Testing
const fs = FruitStand()

// Add fruits
fs.addFruit('Banana', 10, 1.25)
fs.addFruit('Apple', 20, 1.35)
fs.addFruit('Kiwi', 15, 1.55)

//Get initial total value
const initTotalValue = fs.calcTotalValue()
console.log(`The initial value of the fruits is ${initTotalValue.toFixed(2)}`)
// ==> The initial value of the fruits is 62.75
    
// Update fruits
fs.updateQty('Banana', 5)
fs.updateQty('Kiwi', 3)

// Calculate updated value
const updatedValue = fs.calcTotalValue()
console.log(`The updated value of the fruits is ${updatedValue.toFixed(2)}`)
// ==> The updated value of the fruits is 37.90
    
// Update with fruit not in the list yet
fs.updateQty('Pear', 5)
// ==> The fruit Pear is not yet on the list. Please add it first.
    
// Try add a fruit that is already on the list
fs.addFruit('Banana', 10, 1.65)
// ==> The fruit Banana is already in the list. The new quantity is 15 and the updated price is 1.65