make GetKeyNames work recursively

Chris Santero · Chris Santero · commit 6bf83ccfb18e · 2015-07-16T12:13:04.000-04:00
diff --git a/JSONAPI.EntityFramework.Tests/DbContextExtensionsTests.cs b/JSONAPI.EntityFramework.Tests/DbContextExtensionsTests.cs
@@ -82,7 +82,7 @@ public void GetKeyNamesNotAnEntityTest()
         {
             // Act
             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");
+            action.ShouldThrow<Exception>().Which.Message.Should().Be("Failed to identify the key names for NotAnEntity or any of its parent classes.");
         }
     }
 }
diff --git a/JSONAPI.EntityFramework/DbContextExtensions.cs b/JSONAPI.EntityFramework/DbContextExtensions.cs
@@ -21,16 +21,28 @@ public static class DbContextExtensions
         /// <returns></returns>
         public static IEnumerable<string> GetKeyNames(this DbContext dbContext, Type type)
         {
-            var openMethod = typeof(DbContextExtensions).GetMethod("GetKeyNamesFromGeneric", BindingFlags.Public | BindingFlags.Static);
-            var method = openMethod.MakeGenericMethod(type);
-            try
-            {
-                return (IEnumerable<string>)method.Invoke(null, new object[] { dbContext });
-            }
-            catch (TargetInvocationException ex)
+            if (dbContext == null) throw new ArgumentNullException("dbContext");
+            if (type == null) throw new ArgumentNullException("type");
+
+            var originalType = type;
+
+            while (type != null)
             {
-                throw ex.InnerException;
+                var openMethod = typeof(DbContextExtensions).GetMethod("GetKeyNamesFromGeneric", BindingFlags.Public | BindingFlags.Static);
+                var method = openMethod.MakeGenericMethod(type);
+
+                try
+                {
+                    return (IEnumerable<string>) method.Invoke(null, new object[] {dbContext});
+                }
+                catch (TargetInvocationException)
+                {
+                }
+
+                type = type.BaseType;
             }
+
+            throw new Exception(string.Format("Failed to identify the key names for {0} or any of its parent classes.", originalType.Name));
         }
 
         /// <summary>

Original file line number	Diff line number	Diff line change
`@@ -82,7 +82,7 @@ public void GetKeyNamesNotAnEntityTest()`
`82`	`82`	`{`
`83`	`83`	`// Act`
`84`	`84`	`Action action = () => _context.GetKeyNames(typeof (NotAnEntity));`
`85`		`- action.ShouldThrow<ArgumentException>().Which.Message.Should().Be("The Type NotAnEntity was not found in the DbContext with Type TestDbContext");`
	`85`	`+ action.ShouldThrow<Exception>().Which.Message.Should().Be("Failed to identify the key names for NotAnEntity or any of its parent classes.");`
`86`	`86`	`}`
`87`	`87`	`}`
`88`	`88`	`}`