UnitTestsExam20Aug2020

using NUnit.Framework;
using System;
using System.Linq;

namespace Store.Tests
{
    public class StoreManagerTests
    {
        [SetUp]
        public void Setup()
        {
        }

        [Test]
        public void Constructor_ProductsCollectionIsEmpty()
        {
            StoreManager manager = new StoreManager();

            Assert.IsEmpty(manager.Products);
            Assert.AreEqual(0, manager.Count);
        }

        [Test]
        public void ProductsProp_Should_Add_CorrectNumOfProducts()
        {
            StoreManager manager = new StoreManager();
            Product product1 = new Product("name1", 2, 3.00M);
            Product product2 = new Product("name2", 5, 10.00M);

            manager.AddProduct(product1);
            manager.AddProduct(product2);

            Assert.AreEqual(2, manager.Products.Count);
        }

        [Test]
        public void AddProductMethod_Should_ThrowExc_When_NullProduct()
        {
            StoreManager manager = new StoreManager();

            Assert.Throws<ArgumentNullException>(() => manager.AddProduct(null));
        }

        [Test]
        public void AddProductMethod_Should_ThrowExc_When_ProductQtyNegative()
        {
            StoreManager manager = new StoreManager();
            Product product1 = new Product("name1", -2, 3.00M);

            Assert.Throws<ArgumentException>(() => manager.AddProduct(product1));
        }

        [Test]
        public void AddProductMethod_Should_Add_Correct_Part()
        {
            StoreManager manager = new StoreManager();
            Product product1 = new Product("name1", 2, 3.00M);

            manager.AddProduct(product1);

            Product actualProduct = manager.Products.FirstOrDefault(p => p.Name == "name1");

            Assert.IsNotNull(actualProduct.Name);
            Assert.AreEqual("name1", actualProduct.Name);
        }

        [Test]
        public void BuyProduct_Should_ThrowExc_When_NullProduct()
        {
            StoreManager manager = new StoreManager();

            Assert.Throws<ArgumentNullException>(() => manager.BuyProduct("nameA", 10));
        }

        [Test]
        public void BuyProduct_Should_ThrowExc_When_NotEnoughQty()
        {
            StoreManager manager = new StoreManager();
            Product product1 = new Product("name1", 2, 3.00M);

            manager.AddProduct(product1);

            Assert.Throws<ArgumentException>(() => manager.BuyProduct("name1", 10));
        }

        [Test]
        public void BuyProduct_Should_Work_Properly_Qty()
        {
            StoreManager manager = new StoreManager();
            Product product1 = new Product("name1", 6, 3.00M);

            manager.AddProduct(product1);
            manager.BuyProduct("name1", 1);

            Assert.AreEqual(5, product1.Quantity);
        }

        [Test]
        public void BuyProduct_Should_Work_Properly_Price()
        {
            StoreManager manager = new StoreManager();
            Product product1 = new Product("name1", 6, 3.00M);

            manager.AddProduct(product1);
            decimal actualPrice = manager.BuyProduct("name1", 1);

            Assert.AreEqual(product1.Price, actualPrice);
        }

        [Test]
        public void GetTheMostExpensiveProduct_Should_Work_Properly()
        {
            StoreManager manager = new StoreManager();
            Product product1 = new Product("name1", 2, 3.00M);
            Product product2 = new Product("name2", 5, 10.00M);
            Product product3 = new Product("name3", 3, 8.00M);

            manager.AddProduct(product1);
            manager.AddProduct(product2);
            manager.AddProduct(product3);

            var actualProduct = manager.GetTheMostExpensiveProduct();

            Assert.AreEqual(product2, actualProduct);
        }
    }
}