CallBase should not be allowed for delegate mocks

CHANGELOG.md

@@ -10,6 +10,7 @@ The format is loosely based on [Keep a Changelog](http://keepachangelog.com/en/1
 #### Fixed
 
 * `NullReferenceException` when using `SetupSet` on indexers with multiple parameters (@idigra, #694)
+* `CallBase` should not be allowed for delegate mocks (@tehmantra, #706)
 
 
 ## 4.10.0 (2018-09-08)

src/Moq/MethodCall.cs

@@ -123,6 +123,11 @@ public override void Execute(Invocation invocation)
 
 		public virtual void SetCallBaseResponse()
 		{
+			if (this.Mock.TargetType.IsDelegate())
+			{
+				throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, Resources.CallBaseCannotBeUsedWithDelegateMocks));
+			}
+
 			this.callBase = true;
 		}
 

src/Moq/MethodCallReturn.cs

@@ -58,6 +58,11 @@ public override void SetCallbackResponse(Delegate callback)
 
 		public override void SetCallBaseResponse()
 		{
+			if (this.Mock.TargetType.IsDelegate())
+			{
+				throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, Resources.CallBaseCannotBeUsedWithDelegateMocks));
+			}
+
 			this.returnValueKind = ReturnValueKind.CallBase;
 		}
 

src/Moq/Mock.Generic.cs

@@ -6,6 +6,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Globalization;
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
@@ -18,6 +19,7 @@
 
 using Moq.Language;
 using Moq.Language.Flow;
+using Moq.Properties;
 
 namespace Moq
 {
@@ -164,7 +166,15 @@ private void CheckParameters()
 		public override bool CallBase
 		{
 			get => this.callBase;
-			set => this.callBase = value;
+			set
+			{
+				if (value && this.MockedType.IsDelegate())
+				{
+					throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, Resources.CallBaseCannotBeUsedWithDelegateMocks));
+				}
+
+				this.callBase = value;
+			}
 		}
 
 		internal override Dictionary<Type, object> ConfiguredDefaultValues => this.configuredDefaultValues;

src/Moq/Properties/Resources.resx

@@ -348,4 +348,7 @@ Expected invocation on the mock once, but was {4} times: {1}</value>
 		<value>The following invocations on mock '{0}' were not verified:
 {1}</value>
 	</data>
-</root>
+	<data name="CallBaseCannotBeUsedWithDelegateMocks" xml:space="preserve">
+		<value>CallBase cannot be used with Delegate mocks.</value>
+	</data>
+</root>

tests/Moq.Tests/Regressions/IssueReportsFixture.cs

@@ -9,6 +9,7 @@
 using System.Data.Entity.Core.EntityClient;
 #endif
 using System.ComponentModel;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Linq.Expressions;
@@ -2010,6 +2011,51 @@ public interface IMyInterface
 
 		#endregion
 
+		#region 706
+
+		public class Issue706
+		{
+			[Fact]
+			public void CallBase_should_not_be_allowed_for_void_delegate_mocks()
+			{
+				Mock<Action> mock = new Mock<Action>();
+				Language.Flow.ISetup<Action> setup = mock.Setup(m => m());
+
+				Exception ex = Assert.Throws<NotSupportedException>(() => setup.CallBase());
+				Assert.Equal(string.Format(CultureInfo.CurrentCulture, Resources.CallBaseCannotBeUsedWithDelegateMocks), ex.Message);
+			}
+
+			[Fact]
+			public void CallBase_should_not_be_allowed_for_non_void_delegate_mocks()
+			{
+				Mock<Func<bool>> mock = new Mock<Func<bool>>();
+				Language.Flow.ISetup<Func<bool>, bool> setup = mock.Setup(m => m());
+
+				Exception ex = Assert.Throws<NotSupportedException>(() => setup.CallBase());
+				Assert.Equal(string.Format(CultureInfo.CurrentCulture, Resources.CallBaseCannotBeUsedWithDelegateMocks), ex.Message);
+			}
+
+			[Fact]
+			public void CallBase_property_should_not_be_allowed_true_for_delegate_mocks()
+			{
+				Mock<Action> mock = new Mock<Action>();
+
+				Exception ex = Assert.Throws<NotSupportedException>(() => mock.CallBase = true);
+				Assert.Equal(string.Format(CultureInfo.CurrentCulture, Resources.CallBaseCannotBeUsedWithDelegateMocks), ex.Message);
+			}
+
+			[Fact]
+			public void CallBase_property_should_be_allowed_false_for_delegate_mocks()
+			{
+				Mock<Action> mock = new Mock<Action>();
+				mock.CallBase = false;
+
+				Assert.Equal(false, mock.CallBase);
+			}
+		}
+
+		#endregion
+
 		// Old @ Google Code
 
 		#region #47