Checkpoint (still hacking about)

tests/EntityFrameworkCore.Projections.FunctionalTests/ExtensionsMethods/Entity.cs

@@ -0,0 +1,11 @@
+namespace EntityFrameworkCore.Projections.FunctionalTests.ExtensionMethods
+{
+
+    public partial class ExtensionMethodTests
+    {
+        public class Entity
+        {
+            public int Id { get; set; }
+        }    
+    }
+}

tests/EntityFrameworkCore.Projections.FunctionalTests/ExtensionsMethods/EntityExtensions.cs

@@ -0,0 +1,8 @@
+namespace EntityFrameworkCore.Projections.FunctionalTests.ExtensionMethods
+{
+    public static class EntityExtensions
+    {
+        [Projectable]
+        public static int Foo(this ExtensionMethodTests.Entity entity) => entity.Id + 1;
+    }
+}

tests/EntityFrameworkCore.Projections.FunctionalTests/ExtensionsMethods/ExtensionMethodTests.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projections.FunctionalTests.Helpers;
+using Microsoft.EntityFrameworkCore;
+using ScenarioTests;
+using Xunit;
+
+namespace EntityFrameworkCore.Projections.FunctionalTests.ExtensionMethods
+{
+
+    public partial class ExtensionMethodTests
+    {
+        [Scenario(NamingPolicy = ScenarioTestMethodNamingPolicy.Test)]
+        public void PlayScenario(ScenarioContext scenario)
+        {
+            using var dbContext = new SampleDbContext<Entity>();
+
+            scenario.Fact("We can select on a projectable extension method", () => {
+                const string expectedQueryString = "SELECT [e].[Id]\r\nFROM [Entity] AS [e]";
+
+                var query = dbContext.Set<Entity>()
+                    .Select(x => x.Foo());
+
+                Assert.Equal(expectedQueryString, query.ToQueryString());
+            });
+
+        }
+    }
+}

tests/EntityFrameworkCore.Projections.FunctionalTests/StatefullComplexFunctionTests.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Data.SqlTypes;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projections.FunctionalTests.Helpers;
+using EntityFrameworkCore.Projections.Services;
+using Microsoft.EntityFrameworkCore;
+using ScenarioTests;
+using Xunit;
+
+namespace EntityFrameworkCore.Projections.FunctionalTests
+{
+    public partial class StatefullComplexFunctionTests
+    {
+        public record Entity
+        {
+            public int Id { get; set; }
+            
+            [Projectable]
+            public int Computed(int argument) => Id + argument; 
+        }
+
+        [Scenario(NamingPolicy = ScenarioTestMethodNamingPolicy.Test)]
+        public void PlayScenario(ScenarioContext scenario)
+        {
+            // Setup
+            using var dbContext = new SampleDbContext<Entity>(); 
+
+            scenario.Fact("We can filter on a projectable property", () => {
+                const string expectedQueryString =
+@"DECLARE @__argument_0 int = 1;
+
+SELECT [e].[Id]
+FROM [Entity] AS [e]
+WHERE ([e].[Id] + @__argument_0) = 2";
+
+                var query = dbContext.Set<Entity>().AsQueryable()
+                    .Where(x => x.Computed(1) == 2);
+
+                Assert.Equal(expectedQueryString, query.ToQueryString());
+            });
+
+            scenario.Fact("We can select on a projectable property", () => {
+                const string expectedQueryString =
+@"DECLARE @__argument_0 int = 1;
+
+SELECT [e].[Id] + @__argument_0
+FROM [Entity] AS [e]";
+
+                var query = dbContext.Set<Entity>()
+                    .AsQueryable()
+                    .Select(x => x.Computed(1));
+
+                 Assert.Equal(expectedQueryString, query.ToQueryString());
+            });
+
+            scenario.Fact("We can pass in variables", () => {
+                const string expectedQueryString =
+@"DECLARE @__argument_0 int = 1;
+
+SELECT [e].[Id] + @__argument_0
+FROM [Entity] AS [e]";
+
+                var argument = 1;
+                var query = dbContext.Set<Entity>()
+                    .Select(x => x.Computed(argument));
+
+                Assert.Equal(expectedQueryString, query.ToQueryString());
+            });
+        }
+    }
+}

tests/EntityFrameworkCore.Projections.FunctionalTests/StatelessComplexFunctionTests.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using EntityFrameworkCore.Projections.FunctionalTests.Helpers;
+using EntityFrameworkCore.Projections.Services;
 using Microsoft.EntityFrameworkCore;
 using ScenarioTests;
 using Xunit;
@@ -28,25 +29,39 @@ namespace EntityFrameworkCore.Projections.FunctionalTests
             using var dbContext = new SampleDbContext<Entity>(); 
 
             scenario.Fact("We can filter on a projectable property", () => {
-                const string expectedQueryString = "SELECT [e].[Id]\r\nFROM [Entity] AS [e]\r\nWHERE 0 = 1";
+                const string expectedQueryString =
+@"DECLARE @__p_0 bit = CAST(0 AS bit);
 
-                var query = dbContext.Set<Entity>()
+SELECT [e].[Id]
+FROM [Entity] AS [e]
+WHERE @__p_0 = CAST(1 AS bit)";
+
+                var query = dbContext.Set<Entity>().AsQueryable()
                     .Where(x => x.Computed(0) == 1);
 
                 Assert.Equal(expectedQueryString, query.ToQueryString());
             });
 
             scenario.Fact("We can select on a projectable property", () => {
-                const string expectedQueryString = "SELECT 0\r\nFROM [Entity] AS [e]";
+                const string expectedQueryString =
+@"DECLARE @__argument1_0 int = 0;
+
+SELECT @__argument1_0
+FROM [Entity] AS [e]";
 
                 var query = dbContext.Set<Entity>()
+                    .AsQueryable()
                     .Select(x => x.Computed(0));
 
-                Assert.Equal(expectedQueryString, query.ToQueryString());
+                 Assert.Equal(expectedQueryString, query.ToQueryString());
             });
 
             scenario.Fact("We can pass in variables", () => {
-                const string expectedQueryString = "SELECT 0\r\nFROM [Entity] AS [e]";
+                const string expectedQueryString =
+@"DECLARE @__argument1_0 int = 0;
+
+SELECT @__argument1_0
+FROM [Entity] AS [e]";
 
                 var argument = 0;
                 var query = dbContext.Set<Entity>()