Allow to remove items from the basket setting quantity to zero

src/ApplicationCore/Entities/BasketAggregate/Basket.cs

@@ -25,5 +25,10 @@ public void AddItem(int catalogItemId, decimal unitPrice, int quantity = 1)
             var existingItem = Items.FirstOrDefault(i => i.CatalogItemId == catalogItemId);
             existingItem.Quantity += quantity;
         }
+
+        public void RemoveEmptyItems()
+        {
+            _items.RemoveAll(i => i.Quantity == 0);
+        }
     }
 }

src/ApplicationCore/Services/BasketService.cs

@@ -59,10 +59,11 @@ public async Task SetQuantities(int basketId, Dictionary<string, int> quantities
             {
                 if (quantities.TryGetValue(item.Id.ToString(), out var quantity))
                 {
-                    _logger.LogInformation($"Updating quantity of item ID:{item.Id} to {quantity}.");
+                    if(_logger != null) _logger.LogInformation($"Updating quantity of item ID:{item.Id} to {quantity}.");
                     item.Quantity = quantity;
                 }
             }
+            basket.RemoveEmptyItems();
             await _basketRepository.UpdateAsync(basket);
         }
 

src/Web/Pages/Basket/Index.cshtml

@@ -35,7 +35,7 @@
                             <section class="esh-basket-item esh-basket-item--middle col-xs-2">$ @item.UnitPrice.ToString("N2")</section>
                             <section class="esh-basket-item esh-basket-item--middle col-xs-2">
                                 <input type="hidden" name="@("Items[" + i + "].Key")" value="@item.Id" />
-                                <input type="number" class="esh-basket-input" min="1" name="@("Items[" + i + "].Value")" value="@item.Quantity" />
+                                <input type="number" class="esh-basket-input" min="0" name="@("Items[" + i + "].Value")" value="@item.Quantity" />
                             </section>
                             <section class="esh-basket-item esh-basket-item--middle esh-basket-item--mark col-xs-2">$ @Math.Round(item.Quantity * item.UnitPrice, 2).ToString("N2")</section>
                         </div>

tests/IntegrationTests/Repositories/BasketRepositoryTests/SetQuantities.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.eShopWeb.ApplicationCore.Entities.BasketAggregate;
+using Microsoft.eShopWeb.ApplicationCore.Interfaces;
+using Microsoft.eShopWeb.ApplicationCore.Services;
+using Microsoft.eShopWeb.Infrastructure.Data;
+using Microsoft.eShopWeb.UnitTests.Builders;
+using Xunit;
+
+namespace Microsoft.eShopWeb.IntegrationTests.Repositories.BasketRepositoryTests
+{
+    public class SetQuantities
+    {
+        private readonly CatalogContext _catalogContext;
+        private readonly IAsyncRepository<Basket> _basketRepository;
+        private readonly BasketBuilder BasketBuilder = new BasketBuilder();
+
+        public SetQuantities()
+        {
+            var dbOptions = new DbContextOptionsBuilder<CatalogContext>()
+                .UseInMemoryDatabase(databaseName: "TestCatalog")
+                .Options;
+            _catalogContext = new CatalogContext(dbOptions);
+            _basketRepository = new EfRepository<Basket>(_catalogContext);
+        }
+
+        [Fact]
+        public async Task RemoveEmptyQuantities()
+        {
+            var basket = BasketBuilder.WithOneBasketItem();
+            var basketService = new BasketService(_basketRepository, null);
+            await _basketRepository.AddAsync(basket);
+            _catalogContext.SaveChanges();
+
+            await basketService.SetQuantities(BasketBuilder.BasketId, new Dictionary<string, int>() { { BasketBuilder.BasketId.ToString(), 0 } });
+
+            Assert.Equal(0, basket.Items.Count);
+        }
+    }
+}

tests/UnitTests/ApplicationCore/Entities/BasketTests/BasketAddItem.cs

@@ -53,5 +53,15 @@ public void DefaultsToQuantityOfOne()
             var firstItem = basket.Items.Single();
             Assert.Equal(1, firstItem.Quantity);
         }
+
+        [Fact]
+        public void RemoveEmptyItems()
+        {
+            var basket = new Basket();
+            basket.AddItem(_testCatalogItemId, _testUnitPrice, 0);
+            basket.RemoveEmptyItems();
+
+            Assert.Equal(0, basket.Items.Count);
+        }
     }
 }

tests/UnitTests/ApplicationCore/Services/BasketServiceTests/SetQuantities.cs

@@ -5,21 +5,22 @@
 using Moq;
 using System;
 using Xunit;
-
+using System.Threading.Tasks;
+
 namespace Microsoft.eShopWeb.UnitTests.ApplicationCore.Services.BasketServiceTests
 {
     public class SetQuantities
     {
-        private int _invalidId = -1;
-        private Mock<IAsyncRepository<Basket>> _mockBasketRepo;
+        private readonly int _invalidId = -1;
+        private readonly Mock<IAsyncRepository<Basket>> _mockBasketRepo;
 
         public SetQuantities()
         {
             _mockBasketRepo = new Mock<IAsyncRepository<Basket>>();
         }
 
         [Fact]
-        public async void ThrowsGivenInvalidBasketId()
+        public async Task ThrowsGivenInvalidBasketId()
         {
             var basketService = new BasketService(_mockBasketRepo.Object, null);
 
@@ -28,7 +29,7 @@ public async void ThrowsGivenInvalidBasketId()
         }
 
         [Fact]
-        public async void ThrowsGivenNullQuantities()
+        public async Task ThrowsGivenNullQuantities()
         {
             var basketService = new BasketService(null, null);
 

tests/UnitTests/ApplicationCore/Services/BasketServiceTests/TransferBasket.cs

@@ -1,21 +1,22 @@
 using Microsoft.eShopWeb.ApplicationCore.Services;
 using System;
+using System.Threading.Tasks;
 using Xunit;
 
 namespace Microsoft.eShopWeb.UnitTests.ApplicationCore.Services.BasketServiceTests
 {
     public class TransferBasket
     {
         [Fact]
-        public async void ThrowsGivenNullAnonymousId()
+        public async Task ThrowsGivenNullAnonymousId()
         {
             var basketService = new BasketService(null, null);
 
             await Assert.ThrowsAsync<ArgumentNullException>(async () => await basketService.TransferBasketAsync(null, "steve"));
         }
 
         [Fact]
-        public async void ThrowsGivenNullUserId()
+        public async Task ThrowsGivenNullUserId()
         {
             var basketService = new BasketService(null, null);