Loyalty Points - C#

Attention.md

Loyalty Points (C#)

• Create a C# Library Project - you can name it LoyaltyPoints.
• Copy PointsCalculatorTest.cs under project PrivilegeServiceSpecs. Add reference to NUnit in this project.
• Copy Tier.cs, PrivilegeService.cs, PointsCalculator.cs, CustomerRepository.cs and Customer.cs under project PrivilegeService.
• Run the tests to get a green bar.

An airline has following rules for calculating bonus amount for loyalty points for a customer based on which tier they are in:

• If a customer is in Platinum tier, add 50% more points above regular points.
• If a customer is in Gold tier, add 30% more points above regular points.
• If a customer is in Silver tier, add 15% more points above regular points.
• If a customer is in Blue tier, then there are no bonus points, just regular points.
• Spending INR 100 earns a regular point.

Customer.cs

namespace LoyaltyPoints
{
    public class Customer
    {
        public Tier Tier { get; set; }
        public int Points { get; set; }
    }
}

CustomerRepository.cs

namespace LoyaltyPoints
{
    class CustomerRepository
    {
        public Customer FindById(string customerId)
        {
            return new Customer { Points = 120, Tier = Tier.Gold };
        }
    }
}

PointsCalculator.cs

using System;

namespace LoyaltyPoints
{
    public class PointsCalculator
    {
        private static float AMOUNT_PER_POINT = 100.00f;

        public int CalculatePoints(Tier tier, float amountSpent) {
            float earnedPoints = amountSpent / AMOUNT_PER_POINT;
            var points = Math.Floor(earnedPoints + Bonus(tier, earnedPoints));
            return Convert.ToInt32(points);
        }

        private float Bonus(Tier tier, float amountSpent)
        {
            if (tier == Tier.Silver) {
                return 0.15f * amountSpent;
            }
            if (tier == Tier.Gold) {
                return 0.3f * amountSpent;
            }
            if (tier == Tier.Platinum) {
                return 0.5f * amountSpent;
            }
            return 0f;
        }
    }
}

PointsCalculatorTest.cs

using NUnit.Framework;

namespace LoyaltyPoints
{
    [TestFixture]
    public class PointsCalculatorTest
    {
        private PointsCalculator calculator = new PointsCalculator();

        [Test]
        public void BlueCustomerEarnsNoBonusPoints()
        {
            Assert.AreEqual(0, calculator.CalculatePoints(Tier.Blue, 99.99f));
            Assert.AreEqual(1, calculator.CalculatePoints(Tier.Blue, 100.00f));
            Assert.AreEqual(1, calculator.CalculatePoints(Tier.Blue, 199.99f));
            Assert.AreEqual(2, calculator.CalculatePoints(Tier.Blue, 200.00f));
        }

        [Test]
        public void SilverCustomerEarns15PercentBonusPointsAboveBlueCustomer()
        {
            Assert.AreEqual(0, calculator.CalculatePoints(Tier.Silver, 86.95f));
            Assert.AreEqual(1, calculator.CalculatePoints(Tier.Silver, 86.96f));
            Assert.AreEqual(1, calculator.CalculatePoints(Tier.Silver, 173.91f));
            Assert.AreEqual(2, calculator.CalculatePoints(Tier.Silver, 173.92f));
        }

        [Test]
        public void GoldCustomerEarns30PercentBonusPointsAboveBlueCustomer()
        {
            Assert.AreEqual(0, calculator.CalculatePoints(Tier.Gold, 76.92f));
            Assert.AreEqual(1, calculator.CalculatePoints(Tier.Gold, 76.93f));
            Assert.AreEqual(1, calculator.CalculatePoints(Tier.Gold, 153.84f));
            Assert.AreEqual(2, calculator.CalculatePoints(Tier.Gold, 153.85f));
        }

        [Test]
        public void PlatinumCustomerEarns50PercentBonusPointsOverBlueCustomer()
        {
            Assert.AreEqual(0, calculator.CalculatePoints(Tier.Platinum, 66.66f));
            Assert.AreEqual(1, calculator.CalculatePoints(Tier.Platinum, 66.67f));
            Assert.AreEqual(1, calculator.CalculatePoints(Tier.Platinum, 133.33f));
        }
    }
}

PrivilegeService.cs

namespace LoyaltyPoints
{
    public class PrivilegeService
    {
        private readonly PointsCalculator pointsCalculator = new PointsCalculator();

        private CustomerRepository customerRepository = new CustomerRepository();

        public int LoyaltyPoints(string customerId, float amountSpent)
        {
            var customer = customerRepository.FindById(customerId);
            Tier tier = customer.Tier;
            int newPoints = pointsCalculator.CalculatePoints(tier, amountSpent);
            int oldPoints = customer.Points;
            customer.Points = oldPoints + newPoints;
            return customer.Points;
        }

        // Other public methods
        // Tier updateTier(Customer customer);
        // ...
    }
}

Tier.cs

namespace LoyaltyPoints
{
    public enum Tier
    {
        Platinum = 0,
        Gold = 1,
        Silver = 2, 
        Blue = 3
    }
}

How do you run this program?

please provide the main method as well

Tests are good enough, you don't really need a Main method. If you still need it, it will not take much time to hand-toss one on your own