Merge pull request #76 from pimterry/namedMocks

Give mocks names

Source/Interceptor.cs

@@ -117,7 +117,8 @@ private IEnumerable<IInterceptStrategy> InterceptionStrategies()
 		{
 			yield return new HandleDestructor();
 			yield return new HandleTracking();
-			yield return new CheckMockMixing();
+			yield return new InterceptMockPropertyMixin();
+			yield return new InterceptToStringMixin();
 			yield return new AddActualInvocation();
 			yield return new ExtractProxyCall();
 			yield return new ExecuteCall();

Source/InterceptorStrategies.cs

@@ -111,39 +111,41 @@ public InterceptionAction HandleIntercept(ICallContext invocation, InterceptorCo
 
     }
 
-    internal class CheckMockMixing : IInterceptStrategy
+    internal class InterceptMockPropertyMixin : IInterceptStrategy
     {
-
-        public CheckMockMixing()
-        {
-
-        }
         public InterceptionAction HandleIntercept(ICallContext invocation, InterceptorContext ctx, CurrentInterceptContext localctx)
         {
-            if (invocation.Method.DeclaringType.IsGenericType &&
-                    invocation.Method.DeclaringType.GetGenericTypeDefinition() == typeof(IMocked<>))
+            var method = invocation.Method;
+
+            if (typeof(IMocked).IsAssignableFrom(method.DeclaringType) && method.Name == "get_Mock")
             {
-                // "Mixin" of IMocked<T>.Mock
                 invocation.ReturnValue = ctx.Mock;
                 return InterceptionAction.Stop;
             }
-            else if (invocation.Method.DeclaringType == typeof(IMocked))
+
+            return InterceptionAction.Continue;
+        }
+    }
+
+    internal class InterceptToStringMixin : IInterceptStrategy
+    {
+        public InterceptionAction HandleIntercept(ICallContext invocation, InterceptorContext ctx, CurrentInterceptContext localctx)
+        {
+            var method = invocation.Method;
+
+            if (method.DeclaringType == typeof(Object) && method.Name == "ToString")
             {
-                // "Mixin" of IMocked.Mock
-                invocation.ReturnValue = ctx.Mock;
+                invocation.ReturnValue = ctx.Mock.ToString() + ".Object";
                 return InterceptionAction.Stop;
             }
+
             return InterceptionAction.Continue;
         }
     }
 
     internal class HandleTracking : IInterceptStrategy
     {
 
-        public HandleTracking()
-        {
-
-        }
         public InterceptionAction HandleIntercept(ICallContext invocation, InterceptorContext ctx, CurrentInterceptContext localctx)
         {
             // Track current invocation if we're in "record" mode in a fluent invocation context.
@@ -166,10 +168,6 @@ public InterceptionAction HandleIntercept(ICallContext invocation, InterceptorCo
     internal class AddActualInvocation : IInterceptStrategy
     {
 
-        public AddActualInvocation()
-        {
-
-        }
         /// <summary>
         /// Get an eventInfo for a given event name.  Search type ancestors depth first if necessary.
         /// </summary>

Source/Mock.Generic.cs

@@ -39,8 +39,10 @@
 // http://www.opensource.org/licenses/bsd-license.php]
 
 using System;
+using System.CodeDom;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq.Expressions;
+using Microsoft.CSharp;
 using Moq.Language.Flow;
 using Moq.Proxy;
 using Moq.Language;
@@ -102,6 +104,8 @@ public Mock(MockBehavior behavior, params object[] args)
 				args = new object[] { null };
 			}
 
+			this.Name = GenerateMockName();
+
 			this.Behavior = behavior;
 			this.Interceptor = new Interceptor(behavior, typeof(T), this);
 			this.constructorArguments = args;
@@ -110,6 +114,24 @@ public Mock(MockBehavior behavior, params object[] args)
 			this.CheckParameters();
 		}
 
+		private string GenerateMockName()
+		{
+			var randomId = Guid.NewGuid().ToString("N").Substring(0, 4);
+
+			var typeName = typeof (T).FullName;
+
+			if (typeof (T).IsGenericType)
+			{
+				using (var provider = new CSharpCodeProvider())
+				{
+					var typeRef = new CodeTypeReference(typeof(T));
+					typeName = provider.GetTypeOutput(typeRef);
+				}
+			}
+
+			return "Mock<" + typeName + ":" + randomId + ">";
+		}
+
 		private void CheckParameters()
 		{
 			typeof(T).ThrowIfNotMockeable();
@@ -139,7 +161,16 @@ public virtual new T Object
 			get { return (T)base.Object; }
 		}
 
-        internal override bool IsDelegateMock
+		/// <include file='Mock.Generic.xdoc' path='docs/doc[@for="Mock{T}.Name"]/*'/>
+		public string Name { get; set; }
+
+		/// <include file='Mock.Generic.xdoc' path='docs/doc[@for="Mock{T}.ToString"]/*'/>
+		public override string ToString()
+		{
+			return this.Name;
+		}
+
+		internal override bool IsDelegateMock
         {
             get { return typeof(T).IsDelegate(); }
         }

Source/Mock.Generic.xdoc

@@ -107,6 +107,16 @@
 			Exposes the mocked object instance.
 		</summary>
 	</doc>
+	<doc for="Mock{T}.Name">
+		<summary>
+			Allows naming of your mocks, so they can be easily identified in error messages (e.g. from failed assertions).
+		</summary>
+	</doc>
+	<doc for="Mock{T}.ToString">
+		<summary>
+			Returns the name of the mock
+		</summary>
+	</doc>
 	<doc for="Mock{T}.Setup">
 		<summary>
 			Specifies a setup on the mocked type for a call to

Source/Moq.csproj

@@ -86,6 +86,7 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>IReturns.tt</DependentUpon>
     </Compile>
+    <Compile Include="Proxy\ProxyGenerationHelpers.cs" />
     <Compile Include="ReturnsExtensions.cs" />
     <Compile Include="Language\ISetupSequentialResult.cs" />
     <Compile Include="Language\ISetupConditionResult.cs" />

Source/Proxy/CastleProxyFactory.cs

@@ -66,24 +66,24 @@ static CastleProxyFactory()
 			AttributesToAvoidReplicating.Add<ReflectionPermissionAttribute>();
 			AttributesToAvoidReplicating.Add<PermissionSetAttribute>();
 			AttributesToAvoidReplicating.Add<System.Runtime.InteropServices.MarshalAsAttribute>();
-            AttributesToAvoidReplicating.Add<UIPermissionAttribute>();
+			AttributesToAvoidReplicating.Add<UIPermissionAttribute>();
 #if !NET3x
 			AttributesToAvoidReplicating.Add<System.Runtime.InteropServices.TypeIdentifierAttribute>();
 #endif
 #endif
+			proxyOptions = new ProxyGenerationOptions { Hook = new ProxyMethodHook(), BaseTypeForInterfaceProxy = typeof(InterfaceProxy) };
 		}
 
 		/// <inheritdoc />
 		public object CreateProxy(Type mockType, ICallInterceptor interceptor, Type[] interfaces, object[] arguments)
 		{
-			if (mockType.IsInterface)
-			{
-				return generator.CreateInterfaceProxyWithoutTarget(mockType, interfaces, new Interceptor(interceptor));
+			if (mockType.IsInterface) {
+				return generator.CreateInterfaceProxyWithoutTarget(mockType, interfaces, proxyOptions, new Interceptor(interceptor));
 			}
 
 			try
 			{
-				return generator.CreateClassProxy(mockType, interfaces, ProxyGenerationOptions.Default, arguments, new Interceptor(interceptor));
+				return generator.CreateClassProxy(mockType, interfaces, proxyOptions, arguments, new Interceptor(interceptor));
 			}
 			catch (TypeLoadException e)
 			{
@@ -96,6 +96,7 @@ public object CreateProxy(Type mockType, ICallInterceptor interceptor, Type[] in
 		}
 
 		private static readonly Dictionary<Type, Type> delegateInterfaceCache = new Dictionary<Type, Type>();
+		private static readonly ProxyGenerationOptions proxyOptions;
 		private static int delegateInterfaceSuffix;
 
 		/// <inheritdoc />

Source/Proxy/ProxyGenerationHelpers.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using Castle.DynamicProxy;
+
+namespace Moq.Proxy
+{
+	/// <summary>
+	/// Hook used to tells Castle which methods to proxy in mocked classes.
+	/// 
+	/// Here we proxy the default methods Castle suggests (everything Object's methods)
+	/// plus Object.ToString(), so we can give mocks useful default names.
+	/// 
+	/// This is required to allow Moq to mock ToString on proxy *class* implementations.
+	/// </summary>
+	internal class ProxyMethodHook : AllMethodsHook
+	{
+		/// <summary>
+		/// Extends AllMethodsHook.ShouldInterceptMethod to also intercept Object.ToString().
+		/// </summary>
+		public override bool ShouldInterceptMethod(Type type, MethodInfo methodInfo)
+		{
+			var isObjectToString = methodInfo.DeclaringType == typeof(Object) && methodInfo.Name == "ToString";
+			return base.ShouldInterceptMethod(type, methodInfo) || isObjectToString;
+		}
+	}
+
+	/// <summary>
+	/// The base class used for all our interface-inheriting proxies, which overrides the default
+	/// Object.ToString() behavior, to route it via the mock by default, unless overriden by a
+	/// real implementation. 
+	/// 
+	/// This is required to allow Moq to mock ToString on proxy *interface* implementations.
+	/// </summary>
+	internal abstract class InterfaceProxy
+	{
+		public override string ToString()
+		{
+			return ((IMocked)this).Mock.ToString() + ".Object";
+		}
+	}
+}

UnitTests/MockFixture.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections;
+using System.Collections.Generic;
 using System.Linq.Expressions;
 using Xunit;
 
@@ -16,6 +18,80 @@ public void CreatesMockAndExposesInterface()
 			Assert.NotNull(comparable);
 		}
 
+		[Fact]
+		public void CanBeNamedForEasierDebugging()
+		{
+			var mock = new Mock<IComparable>();
+			mock.Name = "my mock";
+
+			Assert.Equal("my mock", mock.ToString());
+		}
+
+		[Fact]
+		public void HasADefaultNameThatIsUnique()
+		{
+			var mock = new Mock<IComparable>();
+			var mock2 = new Mock<IComparable>();
+
+			Assert.NotEqual(mock.ToString(), mock2.ToString());
+		}
+
+		[Fact]
+		public void HasADefaultNameThatIncludesItsTypeAndThatItsAMock()
+		{
+			var mock = new Mock<IComparable>();
+
+			Assert.Contains("System.IComparable", mock.ToString());
+			Assert.Contains("mock", mock.ToString().ToLower());
+		}
+
+		[Fact]
+		public void HasADefaultNameThatIncludesItsGenericParameters()
+		{
+			var mock = new Mock<Dictionary<int, string>>();
+
+			Assert.Contains("System.Collections.Generic.Dictionary<int, string>", mock.ToString());
+		}
+
+		[Fact]
+		public void PassesItsNameOnToTheResultingMockObjectWhenMockingInterfaces()
+		{
+			var mock = new Mock<IComparable>();
+
+			Assert.Equal(mock.ToString() + ".Object", mock.Object.ToString());
+		}
+
+		[Fact]
+		public void PassesItsNameOnToTheResultingMockObjectWhenMockingClasses()
+		{
+			var mock = new Mock<ArrayList>();
+
+			Assert.Equal(mock.ToString() + ".Object", mock.Object.ToString());
+		}
+
+		public class ToStringOverrider
+		{
+			public override string ToString() {
+				return "real value";
+			}
+		}
+
+		[Fact]
+		public void OverriddenToStringMethodsCallUnderlyingImplementationInPartialMocks()
+		{
+			var partialMock = new Mock<ToStringOverrider>() { CallBase = true };
+
+			Assert.Equal("real value", partialMock.Object.ToString());
+		}
+
+		[Fact]
+		public void OverriddenToStringMethodsAreStubbedWithDefaultValuesInFullMocks()
+		{
+			var fullMock = new Mock<ToStringOverrider>();
+
+			Assert.Null(fullMock.Object.ToString());
+		}
+
 		[Fact]
 		public void ThrowsIfNullExpectAction()
 		{
@@ -148,7 +224,7 @@ public void HashCodeIsDifferentForEachMock()
 		}
 
 		[Fact]
-		public void ToStringIsNullOrEmpty()
+		public void ToStringIsNotNullOrEmpty()
 		{
 			var mock = new Mock<IFoo>();
 			Assert.False(String.IsNullOrEmpty(mock.Object.ToString()));