Added features to delete and update quantity of items

Server/Endpoints/Cart/CartController.cs

@@ -2,6 +2,7 @@ using System.Threading.Tasks;
 using MediatR;
 using Microsoft.AspNetCore.Mvc;
 using ShoppingCartStarter.Shared.Cart;
+using ShoppingCartStarter.Shared.Cart.LineItem;
 
 namespace ShoppingCartStarter.Server.Endpoints.Cart
 {
@@ -21,5 +22,19 @@ namespace ShoppingCartStarter.Server.Endpoints.Cart
             var cart = await _mediator.Send(query);
             return Ok(cart);
         }
+
+        [HttpDelete("lines/{id}")]
+        public async Task<IActionResult> Delete(Delete.Command command)
+        {
+            await _mediator.Send(command);
+            return Ok();
+        }
+
+        [HttpPut("lines")]
+        public async Task<IActionResult> Update([FromBody]Update.Command command)
+        {
+            await _mediator.Send(command);
+            return Ok();
+        }
     }
 }

Server/Endpoints/Cart/Details.cs

@@ -21,6 +21,7 @@ namespace ShoppingCartStarter.Server.Endpoints.Cart
         {
             // in reality we'd retrieve a specific cart (for the current user/session) but for demo
             // purposes this just pulls back the first cart it finds
+            
             var cart = await _context.Carts
                 .Include(x => x.LineItems)
                 .FirstOrDefaultAsync(cancellationToken: cancellationToken);

Server/Endpoints/Cart/LineItem/Delete.cs

@@ -0,0 +1,33 @@
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using ShoppingCartStarter.Server.Data;
+using ShoppingCartStarter.Shared.Cart.LineItem;
+
+namespace ShoppingCartStarter.Server.Endpoints.Cart.LineItem
+{
+    public class DeleteHandler : AsyncRequestHandler<Delete.Command>
+    {
+        private readonly StoreContext _context;
+
+        public DeleteHandler(StoreContext context)
+        {
+            _context = context;
+        }
+
+        protected override async Task Handle(Delete.Command request, CancellationToken cancellationToken)
+        {
+            // in reality we'd have more than one cart and would need to locate the correct one here
+            // for the current user/session
+            
+            var cart = await _context.Carts.Include(x => x.LineItems)
+                .FirstOrDefaultAsync(cancellationToken: cancellationToken);
+            
+            var toDelete = cart.LineItems.Single(x => x.Id == request.Id);
+            cart.LineItems.Remove(toDelete);
+            await _context.SaveChangesAsync(cancellationToken);
+        }
+    }
+}

Server/Endpoints/Cart/LineItem/Update.cs

@@ -0,0 +1,35 @@
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using ShoppingCartStarter.Server.Data;
+using ShoppingCartStarter.Shared.Cart.LineItem;
+
+namespace ShoppingCartStarter.Server.Endpoints.Cart.LineItem
+{
+    public class UpdateHandler : AsyncRequestHandler<Update.Command>
+    {
+        private readonly StoreContext _context;
+
+        public UpdateHandler(StoreContext context)
+        {
+            _context = context;
+        }
+
+        protected override async Task Handle(Update.Command request, CancellationToken cancellationToken)
+        {
+            // find the cart (in reality we'd use the customer's id or similar to do this)
+            var cart = await _context.Carts
+                .Include(x => x.LineItems)
+                .FirstOrDefaultAsync(cancellationToken: cancellationToken);
+
+            // find the relevant line and adjust its quantity
+            var line = cart.LineItems.Single(x => x.Id == request.Id);
+            line.Quantity = request.Quantity;
+
+            // save changes
+            await _context.SaveChangesAsync(cancellationToken);
+        }
+    }
+}

Shared/Cart/LineItem/Delete.cs

@@ -0,0 +1,12 @@
+using MediatR;
+
+namespace ShoppingCartStarter.Shared.Cart.LineItem
+{
+    public class Delete
+    {
+        public class Command : IRequest
+        {
+            public int Id { get; set; }
+        }
+    }
+}

Shared/Cart/LineItem/Update.cs

@@ -0,0 +1,13 @@
+using MediatR;
+
+namespace ShoppingCartStarter.Shared.Cart.LineItem
+{
+    public class Update
+    {
+        public class Command : IRequest
+        {
+            public int Id { get; set; }
+            public int Quantity { get; set; }
+        }
+    }
+}