move cost calculation to float aggregate

TransactionProcessor.Aggregates.Tests/FloatAggregateTests.cs

@@ -108,5 +108,19 @@ public void FloatAggregate_RecordCreditPurchase_DuplicateCreditPurchase_ErrorThr
             result.Status.ShouldBe(ResultStatus.Invalid);
 
         }
+
+        [Fact]
+        public void FloatAggregate_GetTotalCostPrice_TotalCostReturned()
+        {
+            Aggregates.FloatAggregate aggregate = Aggregates.FloatAggregate.Create(TestData.FloatAggregateId);
+            aggregate.CreateFloat(TestData.EstateId, TestData.ContractId, TestData.ProductId, TestData.FloatCreatedDateTime);
+            DateTime purchaseDateTime = DateTime.Now;
+            aggregate.RecordCreditPurchase(purchaseDateTime, 1000, 900);
+
+            Decimal totalCost = aggregate.GetTotalCostPrice(10);
+
+            totalCost.ShouldBe(9);
+
+        }
     }
 }

TransactionProcessor.Aggregates/FloatAggregate.cs

@@ -88,6 +88,11 @@ public static Result ValidateCreditIsNotADuplicate(this FloatAggregate aggregate
 
             return Result.Success();
         }
+
+        public static Decimal GetTotalCostPrice(this FloatAggregate aggregate, Decimal transactionAmount)
+        {
+            return transactionAmount * aggregate.UnitCostPrice;
+        }
     }
 
     public record FloatAggregate : Aggregate

TransactionProcessor.BusinessLogic.Tests/Services/TransactionDomainServiceTests.cs

@@ -333,7 +333,7 @@ public async Task TransactionDomainService_ProcessSaleTransaction_TransactionIsP
             this.AggregateService.Setup(t => t.Save(It.IsAny<TransactionAggregate>(), It.IsAny<CancellationToken>()))
                 .ReturnsAsync(Result.Success());
 
-            this.AggregateService.Setup(f => f.GetLatest<FloatAggregate>(It.IsAny<Guid>(), It.IsAny<CancellationToken>())).ReturnsAsync(floatAggregate);
+            this.AggregateService.Setup(f => f.GetLatest<FloatAggregate>(It.IsAny<Guid>(), It.IsAny<CancellationToken>())).ReturnsAsync(Result.Success(floatAggregate));
 
             this.TransactionValidationService.Setup(t => t.ValidateSaleTransaction(It.IsAny<Guid>(),
                                                                                    It.IsAny<Guid>(),

TransactionProcessor.BusinessLogic/Services/TransactionDomainService.cs

@@ -232,10 +232,9 @@ public async Task<Result<ProcessSaleTransactionResponse>> ProcessSaleTransaction
                 Decimal unitCost = 0;
                 Decimal totalCost = 0;
                 if (floatAggregateResult.IsSuccess) {
-                    // TODO: Move calculation to float
                     FloatAggregate floatAggregate = floatAggregateResult.Data;
                     unitCost = floatAggregate.GetUnitCostPrice();
-                    totalCost = transactionAmount.GetValueOrDefault() * unitCost;
+                    totalCost = floatAggregate.GetTotalCostPrice(transactionAmount.GetValueOrDefault());
                 }
 
                 Result stateResult = transactionAggregate.StartTransaction(command.TransactionDateTime, command.TransactionNumber, transactionType, transactionReference, command.EstateId, command.MerchantId, command.DeviceIdentifier, transactionAmount);