started grouping:

PoweredSoft.DynamicLinq.Test/GroupingTests.cs

@@ -0,0 +1,44 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PoweredSoft.DynamicLinq.Test
+{
+    [TestClass]
+    public class GroupingTests
+    {
+        [TestMethod]
+        public void WantedSyntax()
+        {
+            var regularSyntax = TestData.Sales
+                .GroupBy(t => t.ClientId)
+                .Select(t => new
+                {
+                    TheClientId = t.Key,
+                    Count = t.Count(),
+                    CountClientId = t.Count(t2 => t2.ClientId > 1),
+                    LongCount = t.LongCount(),
+                    NetSales = t.Sum(t2 => t2.NetSales),
+                    TaxAverage = t.Average(t2 => t2.Tax),
+                    Sales = t.ToList()
+                });
+            /*
+            var dynamicSyntax = TestData.Sales
+                .GroupBy("ClientId")
+                .Select(t =>
+                {
+                    t.PropertyFromKey("TheClientId", "ClientId");
+                    t.Count("Count");
+                    // don't have to implement right away.
+                    t.Count("CountClientId", "ClientId", ConditionOperators.GreaterThan, 1);
+                    t.LongCount("LongCount");
+                    t.Sum("NetSales");
+                    t.Average("TaxAverage", "Tax");
+                    t.ToList("Sales");
+                });*/
+        }
+    }
+}

PoweredSoft.DynamicLinq.Test/ShortcutTests.cs

@@ -7,15 +7,6 @@ using PoweredSoft.DynamicLinq.Test.Helpers;
 
 namespace PoweredSoft.DynamicLinq.Test
 {
-    internal class MockPersonObject
-    {
-        public string FirstName { get; set; }
-
-        public string LastName { get; set; }
-
-        public int Age { get; set; }
-    }
-
     [TestClass]
     public class ShortcutTests
     {

PoweredSoft.DynamicLinq.Test/TestData.cs

@@ -7,6 +7,31 @@ using System.Threading.Tasks;
 
 namespace PoweredSoft.DynamicLinq.Test
 {
+    internal class MockPersonObject
+    {
+        public string FirstName { get; set; }
+
+        public string LastName { get; set; }
+
+        public int Age { get; set; }
+    }
+
+    internal class MockSale
+    {
+        public long Id { get; set; }
+        public long ClientId { get; set; }
+        public MockClient Client { get; set; }
+        public decimal GrossSales { get; set; }
+        public decimal NetSales { get; set; }
+        public decimal Tax { get; set; }
+    }
+
+    internal class MockClient
+    {
+        public long Id { get; set; }
+        public string Name { get; set; }
+    }
+
     internal static class TestData
     {
         static readonly internal List<MockPersonObject> Persons = new List<MockPersonObject>
@@ -18,6 +43,28 @@ namespace PoweredSoft.DynamicLinq.Test
             new MockPersonObject { FirstName = "Michael", LastName = "Jackson", Age = 58 }
         };
 
+        static readonly internal List<MockClient> Clients = new List<MockClient>
+        {
+            new MockClient { Id = 1, Name = "ACME INC."},
+            new MockClient { Id = 2, Name = "MSLINK" },
+            new MockClient { Id = 3, Name = "COOL GUYS TBD"},
+            new MockClient { Id = 4, Name = "SOME LLC YEAH!" }
+        };
+
+        static readonly internal List<MockSale> Sales = new List<MockSale>
+        {
+            new MockSale { Id = 1, ClientId = 1, Client = Clients.First(t => t.Id == 1), GrossSales = 1000M, NetSales = 890.0M, Tax = 20M },
+            new MockSale { Id = 2, ClientId = 1, Client = Clients.First(t => t.Id == 1), GrossSales = 1100M, NetSales = 180.0M, Tax = 0M },
+            new MockSale { Id = 3, ClientId = 2, Client = Clients.First(t => t.Id == 2), GrossSales = 1200M, NetSales = 920.0M, Tax = 3M },
+            new MockSale { Id = 4, ClientId = 2, Client = Clients.First(t => t.Id == 2), GrossSales = 1330M, NetSales = 800.0M, Tax = 120M },
+            new MockSale { Id = 5, ClientId = 1, Client = Clients.First(t => t.Id == 1), GrossSales = 1400M, NetSales = 990.0M, Tax = 20M },
+            new MockSale { Id = 6, ClientId = 3, Client = Clients.First(t => t.Id == 3), GrossSales = 1500M, NetSales = 290.0M, Tax = 200M },
+            new MockSale { Id = 7, ClientId = 3, Client = Clients.First(t => t.Id == 3), GrossSales = 1600M, NetSales = 230.0M, Tax = 240M },
+            new MockSale { Id = 8, ClientId = 3, Client = Clients.First(t => t.Id == 3), GrossSales = 1700M, NetSales = 330.0M, Tax = 210M },
+            new MockSale { Id = 9, ClientId = 1, Client = Clients.First(t => t.Id == 1), GrossSales = 1800M, NetSales = 890.0M, Tax = 290M },
+            new MockSale { Id = 10, ClientId = 4, Client = Clients.First(t => t.Id == 4), GrossSales = 1900M, NetSales = 490.0M, Tax = 270M }
+        };
+
         static readonly internal List<Post> Posts = new List<Post>()
         {
             new Post