Fix a bug of the order discount and create UTs

modules/EasyAbp.EShop.Orders/src/EasyAbp.EShop.Orders.Domain/EasyAbp/EShop/Orders/Orders/IOrderDiscountDistributor.cs

@@ -5,6 +5,6 @@ namespace EasyAbp.EShop.Orders.Orders;
 
 public interface IOrderDiscountDistributor
 {
-    Task<OrderDiscountDistributionModel> DistributeAsync(IOrder order, Dictionary<IOrderLine, decimal> currentPrices,
-        OrderDiscountInfoModel discount);
+    Task<OrderDiscountDistributionModel> DistributeAsync(IOrder order,
+        Dictionary<IOrderLine, decimal> currentTotalPrices, OrderDiscountInfoModel discount);
 }

modules/EasyAbp.EShop.Orders/src/EasyAbp.EShop.Orders.Domain/EasyAbp/EShop/Orders/Orders/OrderDiscountDistributor.cs

@@ -11,16 +11,17 @@ namespace EasyAbp.EShop.Orders.Orders;
 public class OrderDiscountDistributor : IOrderDiscountDistributor, ITransientDependency
 {
     public virtual Task<OrderDiscountDistributionModel> DistributeAsync(IOrder order,
-        Dictionary<IOrderLine, decimal> currentPrices, OrderDiscountInfoModel discount)
+        Dictionary<IOrderLine, decimal> currentTotalPrices, OrderDiscountInfoModel discount)
     {
         var affectedOrderLines = discount.AffectedOrderLineIds
             .Select(orderLineId => order.OrderLines.Single(x => x.Id == orderLineId))
             .ToList();
 
-        var affectedOrderLinesCurrentPrice =
-            new Money(affectedOrderLines.Sum(x => currentPrices[x]), order.Currency);
+        var affectedOrderLinesCurrentTotalPrice =
+            new Money(affectedOrderLines.Sum(x => currentTotalPrices[x]), order.Currency);
 
-        var totalDiscountAmount = discount.CalculateDiscountAmount(affectedOrderLinesCurrentPrice.Amount, order.Currency);
+        var totalDiscountAmount =
+            discount.CalculateDiscountAmount(affectedOrderLinesCurrentTotalPrice.Amount, order.Currency);
 
         var distributions = new Dictionary<Guid, decimal>();
         var remainingDiscountAmount = totalDiscountAmount;
@@ -28,31 +29,31 @@ public class OrderDiscountDistributor : IOrderDiscountDistributor, ITransientDep
         foreach (var orderLine in affectedOrderLines)
         {
             var calculatedDiscountAmount = new Money(
-                currentPrices[orderLine] / affectedOrderLinesCurrentPrice.Amount *
+                currentTotalPrices[orderLine] / affectedOrderLinesCurrentTotalPrice.Amount *
                 totalDiscountAmount, order.Currency, MidpointRounding.ToZero);
 
-            var discountAmount = calculatedDiscountAmount.Amount > currentPrices[orderLine]
-                ? currentPrices[orderLine]
+            var discountAmount = calculatedDiscountAmount.Amount > currentTotalPrices[orderLine]
+                ? currentTotalPrices[orderLine]
                 : calculatedDiscountAmount.Amount;
 
             distributions[orderLine.Id] = discountAmount;
-            currentPrices[orderLine] -= discountAmount;
+            currentTotalPrices[orderLine] -= discountAmount;
             remainingDiscountAmount -= discountAmount;
         }
 
-        foreach (var orderLine in affectedOrderLines.OrderByDescending(x => currentPrices[x]))
+        foreach (var orderLine in affectedOrderLines.OrderByDescending(x => currentTotalPrices[x]))
         {
             if (remainingDiscountAmount == decimal.Zero)
             {
                 break;
             }
 
-            var discountAmount = remainingDiscountAmount > currentPrices[orderLine]
-                ? currentPrices[orderLine]
+            var discountAmount = remainingDiscountAmount > currentTotalPrices[orderLine]
+                ? currentTotalPrices[orderLine]
                 : remainingDiscountAmount;
 
             distributions[orderLine.Id] += discountAmount;
-            currentPrices[orderLine] -= discountAmount;
+            currentTotalPrices[orderLine] -= discountAmount;
             remainingDiscountAmount -= discountAmount;
         }
 

modules/EasyAbp.EShop.Orders/src/EasyAbp.EShop.Orders.Domain/EasyAbp/EShop/Orders/Orders/OrderDiscountResolver.cs

@@ -55,8 +55,8 @@ public class OrderDiscountResolver : IOrderDiscountResolver, ITransientDependenc
         var affectedOrderLineIdsInEffectGroup = new Dictionary<string, List<Guid>>();
         var usedDiscountNameKeyPairs = new HashSet<(string, string)>();
 
-        var currentPrices =
-            new Dictionary<IOrderLine, decimal>(order.OrderLines.ToDictionary(x => x, x => x.UnitPrice));
+        var currentTotalPrices =
+            new Dictionary<IOrderLine, decimal>(order.OrderLines.ToDictionary(x => x, x => x.TotalPrice));
 
         var distributionModels = new List<OrderDiscountDistributionModel>();
 
@@ -88,7 +88,8 @@ public class OrderDiscountResolver : IOrderDiscountResolver, ITransientDependenc
                 electionModel.TryEnqueue(newCandidateDiscounts);
             }
 
-            var distributionResult = await OrderDiscountDistributor.DistributeAsync(order, currentPrices, discount);
+            var distributionResult =
+                await OrderDiscountDistributor.DistributeAsync(order, currentTotalPrices, discount);
 
             distributionModels.Add(new OrderDiscountDistributionModel(discount, distributionResult.Distributions));
         }

modules/EasyAbp.EShop.Orders/test/EasyAbp.EShop.Orders.Domain.Tests/Orders/DemoOrderDiscountProvider.cs

@@ -14,16 +14,24 @@ public class DemoOrderDiscountProvider : IOrderDiscountProvider
 
     public Task DiscountAsync(OrderDiscountContext context)
     {
-        var firstOrderLine = context.Order.OrderLines.First();
+        var orderLines = context.Order.OrderLines.ToList();
+        var firstOrderLine = orderLines[0];
+        var secondOrderLine = orderLines[1];
 
         var models = new List<OrderDiscountInfoModel>
         {
             new(new List<Guid> { firstOrderLine.Id }, null, "DemoDiscount1", "1", "Demo Discount 1",
-                new DynamicDiscountAmountModel("USD", 0.01m, 0m, null)),
-            new(new List<Guid> { firstOrderLine.Id }, "A", "DemoDiscount2", "2", "Demo Discount 2",
-                new DynamicDiscountAmountModel("USD", 0.1m, 0m, null)),
-            new(new List<Guid> { firstOrderLine.Id }, "A", "DemoDiscount3", "3", "Demo Discount 3",
+                new DynamicDiscountAmountModel("USD", 5.00m, 0m, null)),
+            new(new List<Guid> { secondOrderLine.Id }, "A", "DemoDiscount2", "2", "Demo Discount 2",
+                new DynamicDiscountAmountModel("USD", 0.10m, 0m, null)),
+            new(new List<Guid> { secondOrderLine.Id }, "A", "DemoDiscount3", "3", "Demo Discount 3",
                 new DynamicDiscountAmountModel("USD", 0.05m, 0m, null)),
+            new(new List<Guid> { firstOrderLine.Id, secondOrderLine.Id }, "B", "DemoDiscount4", "4", "Demo Discount 4",
+                new DynamicDiscountAmountModel("USD", 0.01m, 0m, null)),
+            new(new List<Guid> { firstOrderLine.Id, secondOrderLine.Id }, null, "DemoDiscount5", "5", "Demo Discount 5",
+                new DynamicDiscountAmountModel("USD", 0.01m, 0m, null)),
+            new(new List<Guid> { firstOrderLine.Id }, "B", "DemoDiscount6", "6", "Demo Discount 6",
+                new DynamicDiscountAmountModel("USD", 0.00m, 0.55m, null)),
         };
 
         foreach (var model in models)

modules/EasyAbp.EShop.Orders/test/EasyAbp.EShop.Orders.Domain.Tests/Orders/OrderDiscountDistributorTests.cs

@@ -57,11 +57,11 @@ public class OrderDiscountDistributorTests : OrdersDomainTestBase
         var discount = new OrderDiscountInfoModel(order.OrderLines.Select(x => x.Id).ToList(), null, "Test", null,
             null, new DynamicDiscountAmountModel("USD", 0m, discountRate, null));
 
-        var currentPrices =
+        var currentTotalPrices =
             new Dictionary<IOrderLine, decimal>(order.OrderLines.ToDictionary(x => (IOrderLine)x,
-                x => x.UnitPrice));
+                x => x.TotalPrice));
 
-        var distributionResult = await OrderDiscountDistributor.DistributeAsync(order, currentPrices, discount);
+        var distributionResult = await OrderDiscountDistributor.DistributeAsync(order, currentTotalPrices, discount);
 
         order.AddDiscounts(distributionResult);
 
@@ -128,11 +128,11 @@ public class OrderDiscountDistributorTests : OrdersDomainTestBase
         var discount = new OrderDiscountInfoModel(order.OrderLines.Select(x => x.Id).ToList(), null, "Test", null,
             null, new DynamicDiscountAmountModel("USD", discountedAmount, 0m, null));
 
-        var currentPrices =
+        var currentTotalPrices =
             new Dictionary<IOrderLine, decimal>(order.OrderLines.ToDictionary(x => (IOrderLine)x,
-                x => x.UnitPrice));
+                x => x.TotalPrice));
 
-        var distributionResult = await OrderDiscountDistributor.DistributeAsync(order, currentPrices, discount);
+        var distributionResult = await OrderDiscountDistributor.DistributeAsync(order, currentTotalPrices, discount);
 
         order.AddDiscounts(distributionResult);
 

modules/EasyAbp.EShop.Orders/test/EasyAbp.EShop.Orders.Domain.Tests/Orders/OrderDiscountProviderTests.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using EasyAbp.EShop.Products.Products;
 using Microsoft.Extensions.DependencyInjection;
+using NodaMoney;
 using Shouldly;
 using Xunit;
 
@@ -25,7 +26,8 @@ public class OrderDiscountProviderTests : OrdersDomainTestBase
         var createOrderInfoModel = new CreateOrderInfoModel(OrderTestData.Store1Id, null,
             new List<CreateOrderLineInfoModel>
             {
-                new(OrderTestData.Product1Id, OrderTestData.ProductSku1Id, 2)
+                new(OrderTestData.Product1Id, OrderTestData.ProductSku1Id, 2),
+                new(OrderTestData.Product1Id, OrderTestData.ProductSku2Id, 1),
             }
         );
 
@@ -42,7 +44,16 @@ public class OrderDiscountProviderTests : OrdersDomainTestBase
                             {
                                 Id = OrderTestData.ProductSku1Id,
                                 AttributeOptionIds = new List<Guid>(),
-                                Price = 1m,
+                                Price = 100m,
+                                Currency = "USD",
+                                OrderMinQuantity = 1,
+                                OrderMaxQuantity = 100,
+                            },
+                            new()
+                            {
+                                Id = OrderTestData.ProductSku2Id,
+                                AttributeOptionIds = new List<Guid>(),
+                                Price = 2m,
                                 Currency = "USD",
                                 OrderMinQuantity = 1,
                                 OrderMaxQuantity = 100,
@@ -52,14 +63,32 @@ public class OrderDiscountProviderTests : OrdersDomainTestBase
                 }
             }, new Dictionary<Guid, DateTime>());
 
-        order.ActualTotalPrice.ShouldBe(1.89m);
-        order.TotalDiscount.ShouldBe(0.11m);
-        order.OrderDiscounts.Count.ShouldBe(2);
+        var orderLines = order.OrderLines;
+
+        const decimal orderLine1PriceWithoutDiscount = 2 * 100m;
+        const decimal orderLine2PriceWithoutDiscount = 1 * 2m;
+
+        var orderLine1ExpectedPrice = new Money((orderLine1PriceWithoutDiscount - 5m - 0.01m) * (1 - 0.55m), "USD",
+            MidpointRounding.AwayFromZero).Amount;
+        var orderLine2ExpectedPrice = orderLine2PriceWithoutDiscount - 0.1m;
+
+        order.ActualTotalPrice.ShouldBe(orderLine1ExpectedPrice + orderLine2ExpectedPrice);
+        order.TotalDiscount.ShouldBe(order.TotalPrice - order.ActualTotalPrice);
+        order.OrderDiscounts.Count.ShouldBe(5);
+        order.OrderDiscounts.ShouldContain(x =>
+            x.OrderId == order.Id && x.OrderLineId == orderLines[0].Id && x.Name == "DemoDiscount1" &&
+            x.Key == "1" && x.DisplayName == "Demo Discount 1" && x.DiscountedAmount == 5.00m);
+        order.OrderDiscounts.ShouldContain(x =>
+            x.OrderId == order.Id && x.OrderLineId == orderLines[1].Id && x.Name == "DemoDiscount2" &&
+            x.Key == "2" && x.DisplayName == "Demo Discount 2" && x.DiscountedAmount == 0.10m);
+        order.OrderDiscounts.ShouldContain(x =>
+            x.OrderId == order.Id && x.OrderLineId == orderLines[0].Id && x.Name == "DemoDiscount5" &&
+            x.Key == "5" && x.DisplayName == "Demo Discount 5" && x.DiscountedAmount == 0.01m);
         order.OrderDiscounts.ShouldContain(x =>
-            x.OrderId == order.Id && x.OrderLineId == order.OrderLines.First().Id && x.Name == "DemoDiscount1" &&
-            x.Key == "1" && x.DisplayName == "Demo Discount 1" && x.DiscountedAmount == 0.01m);
+            x.OrderId == order.Id && x.OrderLineId == orderLines[1].Id && x.Name == "DemoDiscount5" &&
+            x.Key == "5" && x.DisplayName == "Demo Discount 5" && x.DiscountedAmount == 0m);
         order.OrderDiscounts.ShouldContain(x =>
-            x.OrderId == order.Id && x.OrderLineId == order.OrderLines.First().Id && x.Name == "DemoDiscount2" &&
-            x.Key == "2" && x.DisplayName == "Demo Discount 2" && x.DiscountedAmount == 0.1m);
+            x.OrderId == order.Id && x.OrderLineId == orderLines[0].Id && x.Name == "DemoDiscount6" &&
+            x.Key == "6" && x.DisplayName == "Demo Discount 6" && x.DiscountedAmount == 107.24m);
     }
 }