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The JS Mini Hotel system implements a three-tier cancellation policy based on how far in advance a guest cancels their reservation. This guide explains the policy, penalty calculations, and the cancellation process.

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Three-Tier Cancellation Policy

The cancellation penalty depends on the number of days between the cancellation date and the check-in date:

More than 7 days

No chargeFree cancellation if you cancel more than 7 days before check-in.

3-7 days

50% penaltyHalf of the total reservation price is charged.

Less than 3 days

100% penaltyFull reservation price is charged.

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Penalty Calculation Logic

The cancellation charge is calculated using the getCancellationCharge() function:
utils.js:186-202
export function getCancellationCharge(reservation) {
  const now = Temporal.Now.plainDateISO()
  if (reservation === undefined) {
    return
  }
  const totalPrice = reservation.totalPrice

  const duration = now.until(Temporal.PlainDate.from(reservation.checkIn))

  if (duration.days < 3) {
    return totalPrice
  } else if (duration.days < 8) {
    return 0.5 * totalPrice
  } else {
    return 0
  }
}

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How It Works

1

Get current date

The function captures the current date using Temporal.Now.plainDateISO()
2

Calculate days until check-in

It calculates the duration between now and the check-in date:
const duration = now.until(Temporal.PlainDate.from(reservation.checkIn))
3

Apply policy tiers

Based on duration.days, it applies the appropriate penalty:
  • < 3 days: Return full price (totalPrice)
  • 3-7 days: Return half price (0.5 * totalPrice)
  • > 7 days: Return zero (0)
The totalPrice includes both the room charges and any extras that were added to the reservation.

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Cancelling a Reservation

To cancel a reservation, use the cancelReservation() function:
main.js:222-236
function cancelReservation(hotel, reservationId) {
  const reservation = getReservationById(hotel, reservationId)
  const cancellationCharge = getCancellationCharge(reservation)
  if (!reservation) {
    return 'La reserva no existe, no se puede cancelar'
  }

  const room = getRoomByNumber(hotel, reservation.roomNumber)

  reservation.status = RESERVATION_STATUS.CANCELLED
  room.status = ROOM_STATUS.AVAILABLE
  archiveReservation(hotel, reservation)

  return `Cancelación realizada con una penalización de ${cancellationCharge}€`
}

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What Happens During Cancellation

The reservation status is updated to 'cancelled':
reservation.status = RESERVATION_STATUS.CANCELLED
The room status is reset to 'available':
room.status = ROOM_STATUS.AVAILABLE
This makes the room available for new reservations.
The reservation is moved from active reservations to the history:
utils.js:142-146
export function archiveReservation(hotel, reservation) {
  hotel.history.push(reservation)
  deleteReservation(hotel, reservation)
}
This maintains a record of cancelled reservations for reporting purposes.
The function calculates the cancellation charge and returns a confirmation message:
return `Cancelación realizada con una penalización de ${cancellationCharge}€`

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Cancellation Scenarios

Let’s walk through different cancellation scenarios with real examples:

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Scenario 1: Early Cancellation (No Penalty)

// Today is March 3, 2026
// Reservation check-in: April 10, 2026
// Days until check-in: 38 days

const reservation = {
  id: 'RES-001',
  roomNumber: 301,
  guest: { name: 'Ana García', email: '[email protected]' },
  checkIn: '2026-04-10',
  checkOut: '2026-04-15',
  nights: 5,
  totalPrice: 750,
  status: 'confirmed',
  extras: []
}

​
Scenario 2: Medium Notice (50% Penalty)

// Today is April 5, 2026
// Reservation check-in: April 10, 2026
// Days until check-in: 5 days

const reservation = {
  id: 'RES-002',
  roomNumber: 201,
  checkIn: '2026-04-10',
  checkOut: '2026-04-12',
  totalPrice: 160, // 2 nights × €80
  status: 'confirmed'
}

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Scenario 3: Late Cancellation (100% Penalty)

// Today is April 9, 2026
// Reservation check-in: April 10, 2026
// Days until check-in: 1 day

const reservation = {
  id: 'RES-003',
  roomNumber: 101,
  checkIn: '2026-04-10',
  checkOut: '2026-04-13',
  totalPrice: 150, // 3 nights × €50
  status: 'confirmed'
}

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Scenario 4: Cancellation with Extras

// Today is April 7, 2026
// Reservation check-in: April 10, 2026
// Days until check-in: 3 days

const reservation = {
  id: 'RES-004',
  roomNumber: 301,
  checkIn: '2026-04-10',
  checkOut: '2026-04-15',
  nights: 5,
  totalPrice: 875, // €750 room + €125 extras
  status: 'confirmed',
  extras: [
    { name: 'Breakfast', price: 10, quantity: 5 },
    { name: 'Parking', price: 15, quantity: 5 }
  ]
}
The penalty is calculated on the total price, which includes both room charges and extras. Guests cannot get a refund on extras while cancelling the room.

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Error Handling

The cancellation function handles invalid reservation IDs: 
const result = cancelReservation(hotel, 'RES-INVALID')
console.log(result)
// "La reserva no existe, no se puede cancelar"

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Policy Boundary Cases

Pay special attention to these boundary cases:
Cancelling exactly 3 days before check-in:
// duration.days = 3
// Condition: duration.days < 8 is true (50% penalty)
// Result: 50% penalty applied
The policy is: < 3 days = 100%, 3-7 days = 50%, ≥ 8 days = 0%

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Complete Cancellation Example

Here’s a complete example with logging:
main.js:78
// Original example from source code
console.log('Reserva cancelada', cancelReservation(hotel, 'RES-001'))

// 1. Create a reservation
const reservation = createReservation(
  hotel,
  301,
  {
    name: 'Ana García',
    email: '[email protected]',
    phone: '+34 612345678',
    dni: '12345678A'
  },
  '2026-04-10',
  '2026-04-15'
)

console.log('Created:', reservation.id)
console.log('Total price:', reservation.totalPrice)

// 2. Add extras
addExtras(hotel, reservation.id, [
  { name: 'Breakfast', price: 10, quantity: 5 }
])

console.log('Price with extras:', reservation.totalPrice)

// 3. Cancel the reservation
const cancellationMessage = cancelReservation(hotel, reservation.id)
console.log(cancellationMessage)

// 4. Verify cancellation
const cancelledReservation = getReservationById(hotel, reservation.id)
console.log('Found in active reservations:', cancelledReservation)
// undefined (moved to history)

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Checking Cancellation Charge Before Cancelling

You can check the cancellation charge without actually cancelling: 
const reservation = getReservationById(hotel, 'RES-001')
const charge = getCancellationCharge(reservation)

if (charge === 0) {
  console.log('Free cancellation available')
  cancelReservation(hotel, 'RES-001')
} else {
  console.log(`Cancellation will cost €${charge}`)
  // Ask user for confirmation before cancelling
}

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Next Steps

Creating Reservations

Learn how to create reservations that can be cancelled

Generating Reports

View cancelled reservations in guest history reports

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