extract key-name determination facility

Chris Santero · Chris Santero · commit 44fa79beedd5 · 2015-03-19T18:05:12.000-04:00
Figured this made more sense as an extension method.
diff --git a/JSONAPI.EntityFramework.Tests/DbContextExtensionsTests.cs b/JSONAPI.EntityFramework.Tests/DbContextExtensionsTests.cs
@@ -7,13 +7,11 @@
 using FluentAssertions;
 using System.Collections.Generic;
 using System.Data.Entity;
-using JSONAPI.Core;
-using Moq;
 
 namespace JSONAPI.EntityFramework.Tests
 {
     [TestClass]
-    public class EntityFrameworkMaterializerTests
+    public class DbContextExtensionsTests
     {
         private class TestDbContext : DbContext
         {
@@ -60,12 +58,8 @@ private void CleanupTest()
         [TestMethod]
         public void GetKeyNamesStandardIdTest()
         {
-            // Arrange
-            var mockMetadataManager = new Mock<IMetadataManager>(MockBehavior.Strict);
-            var materializer = new EntityFrameworkMaterializer(_context, mockMetadataManager.Object);
-
             // Act
-            IEnumerable<string> keyNames = materializer.GetKeyNames(typeof(Post)).ToArray();
+            IEnumerable<string> keyNames = _context.GetKeyNames(typeof(Post)).ToArray();
 
             // Assert
             keyNames.Count().Should().Be(1);
@@ -75,12 +69,8 @@ public void GetKeyNamesStandardIdTest()
         [TestMethod]
         public void GetKeyNamesNonStandardIdTest()
         {
-            // Arrange
-            var mockMetadataManager = new Mock<IMetadataManager>(MockBehavior.Strict);
-            var materializer = new EntityFrameworkMaterializer(_context, mockMetadataManager.Object);
-
             // Act
-            IEnumerable<string> keyNames = materializer.GetKeyNames(typeof(Backlink)).ToArray();
+            IEnumerable<string> keyNames = _context.GetKeyNames(typeof(Backlink)).ToArray();
 
             // Assert
             keyNames.Count().Should().Be(1);
@@ -90,12 +80,8 @@ public void GetKeyNamesNonStandardIdTest()
         [TestMethod]
         public void GetKeyNamesNotAnEntityTest()
         {
-            // Arrange
-            var mockMetadataManager = new Mock<IMetadataManager>(MockBehavior.Strict);
-            var materializer = new EntityFrameworkMaterializer(_context, mockMetadataManager.Object);
-
             // Act
-            Action action = () => materializer.GetKeyNames(typeof (NotAnEntity));
+            Action action = () => _context.GetKeyNames(typeof (NotAnEntity));
             action.ShouldThrow<ArgumentException>().Which.Message.Should().Be("The Type NotAnEntity was not found in the DbContext with Type TestDbContext");
         }
     }
diff --git a/JSONAPI.EntityFramework.Tests/JSONAPI.EntityFramework.Tests.csproj b/JSONAPI.EntityFramework.Tests/JSONAPI.EntityFramework.Tests.csproj
@@ -116,7 +116,7 @@
     <Compile Include="Acceptance\AcceptanceTestsBase.cs" />
     <Compile Include="Acceptance\SortingTests.cs" />
     <Compile Include="ActionFilters\AsynchronousEnumerationTransformerTests.cs" />
-    <Compile Include="EntityFrameworkMaterializerTests.cs" />
+    <Compile Include="DbContextExtensionsTests.cs" />
     <Compile Include="Helpers\TestDbAsyncEnumerable.cs" />
     <Compile Include="Helpers\WaitsUntilCancellationDbAsyncEnumerator.cs" />
     <Compile Include="Helpers\TestDbAsyncEnumerator.cs" />
diff --git a/JSONAPI.EntityFramework/DbContextExtensions.cs b/JSONAPI.EntityFramework/DbContextExtensions.cs
@@ -0,0 +1,48 @@
+&#65279;using System;
+using System.Collections.Generic;
+using System.Data.Entity;
+using System.Data.Entity.Core.Objects;
+using System.Data.Entity.Infrastructure;
+using System.Linq;
+using System.Reflection;
+
+namespace JSONAPI.EntityFramework
+{
+    internal static class DbContextExtensions
+    {
+        internal static IEnumerable<string> GetKeyNames(this DbContext dbContext, Type type)
+        {
+            var openMethod = typeof(DbContextExtensions).GetMethod("GetKeyNamesFromGeneric", BindingFlags.NonPublic | BindingFlags.Static);
+            var method = openMethod.MakeGenericMethod(type);
+            try
+            {
+                return (IEnumerable<string>)method.Invoke(null, new object[] { dbContext });
+            }
+            catch (TargetInvocationException ex)
+            {
+                throw ex.InnerException;
+            }
+        }
+
+        // ReSharper disable once UnusedMember.Local
+        private static IEnumerable<string> GetKeyNamesFromGeneric<T>(this DbContext dbContext) where T : class
+        {
+            var objectContext = ((IObjectContextAdapter)dbContext).ObjectContext;
+            ObjectSet<T> objectSet;
+            try
+            {
+                objectSet = objectContext.CreateObjectSet<T>();
+
+            }
+            catch (InvalidOperationException e)
+            {
+                throw new ArgumentException(
+                    String.Format("The Type {0} was not found in the DbContext with Type {1}", typeof(T).Name, dbContext.GetType().Name),
+                    e
+                    );
+            }
+            return objectSet.EntitySet.ElementType.KeyMembers.Select(k => k.Name).ToArray();
+        }
+
+    }
+}
diff --git a/JSONAPI.EntityFramework/JSONAPI.EntityFramework.csproj b/JSONAPI.EntityFramework/JSONAPI.EntityFramework.csproj
@@ -71,6 +71,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ActionFilters\AsynchronousEnumerationTransformer.cs" />
+    <Compile Include="DbContextExtensions.cs" />
     <Compile Include="EntityFrameworkMaterializer.cs" />
     <Compile Include="EntityFrameworkMaterializer_Util.cs" />
     <Compile Include="Http\ApiController.cs" />
