added tests for the sumbyasync methods

CoreIntegrationTests/Infrastructure/MongoDbDocumentTestBase.cs

@@ -1075,6 +1075,33 @@ namespace CoreIntegrationTests.Infrastructure
 
         #endregion Index Management
 
+        #region Math
+
+        [Fact]
+        public async Task SumByAsync()
+        {
+            // Arrange
+            var criteria = $"{GetTestName()}.{DocumentTypeName}.{Guid.NewGuid()}";
+            var documents = CreateTestDocuments(5);
+            var i = 1;
+            documents.ForEach(e =>
+            {
+                e.Nested.SomeDate = e.Nested.SomeDate.AddDays(i++);
+                e.Nested.SomeAmount = 5m;
+                e.SomeContent = criteria;
+            });
+            SUT.AddMany<T>(documents);
+            var expectedSum = documents.Sum(e => e.Nested.SomeAmount);
+
+            // Act
+            var result = await SUT.SumByAsync<T>(e => e.SomeContent == criteria, e => e.Nested.SomeAmount, PartitionKey);
+
+            // Assert
+            Assert.Equal(expectedSum, result);
+        }
+
+        #endregion Math
+
         #region Test Utils
 
         [MethodImpl(MethodImplOptions.NoInlining)]

CoreIntegrationTests/Infrastructure/MongoDbTKeyDocumentTestBase.cs

@@ -1068,6 +1068,33 @@ namespace CoreIntegrationTests.Infrastructure
 
         #endregion Index Management
 
+        #region Math
+
+        [Fact]
+        public async Task SumByAsync()
+        {
+            // Arrange
+            var criteria = $"{GetTestName()}.{DocumentTypeName}.{Guid.NewGuid()}";
+            var documents = CreateTestDocuments(5);
+            var i = 1;
+            documents.ForEach(e =>
+            {
+                e.Nested.SomeDate = e.Nested.SomeDate.AddDays(i++);
+                e.Nested.SomeAmount = 5m;
+                e.SomeContent = criteria;
+            });
+            SUT.AddMany<T, TKey>(documents);
+            var expectedSum = documents.Sum(e => e.Nested.SomeAmount);
+
+            // Act
+            var result = await SUT.SumByAsync<T, TKey>(e => e.SomeContent == criteria, e => e.Nested.SomeAmount, PartitionKey);
+
+            // Assert
+            Assert.Equal(expectedSum, result);
+        }
+
+        #endregion Math
+
         #region Test Utils
         [MethodImpl(MethodImplOptions.NoInlining)]
         private string GetCurrentMethod()

CoreIntegrationTests/Infrastructure/TestClasses.cs

@@ -1,4 +1,5 @@
-using MongoDB.Bson.Serialization.Attributes;
+using MongoDB.Bson;
+using MongoDB.Bson.Serialization.Attributes;
 using MongoDbGenericRepository.Models;
 using MongoDbGenericRepository.Utils;
 using System;
@@ -21,6 +22,8 @@ namespace CoreIntegrationTests.Infrastructure
     public class Nested
     {
         public DateTime SomeDate { get; set; }
+        [BsonRepresentation(BsonType.Decimal128)]
+        public decimal SomeAmount { get; set; }
     }
 
     public class Child