Make conditionalSetup.Verifiable() an error

CHANGELOG.md

@@ -14,6 +14,10 @@ The format is loosely based on [Keep a Changelog](http://keepachangelog.com/en/1
 
  * Two new public methods in `Times`: `bool Validate(int count)` and `string ToString()` (@stakx, 975)
 
+#### Changed
+
+ * Attempts to mark conditionals setup as verifiable are now considered an error, since conditional setups are ignored during verification. Calls to `.Verifiable()` on conditional setups are no-ops and can be safely removed. (@stakx, #997)
+
 #### Fixed
 
  * Regression: Restored `Capture.In` use in `mock.Verify(expression, ...)` to extract arguments of previously recorded invocations. (@vgriph, #968; @stakx, #974)

src/Moq/Properties/Resources.resx

@@ -351,4 +351,7 @@ This could be caused by an unrecognized type conversion, coercion, narrowing, or
   <data name="UseItIsOtherOverload" xml:space="preserve">
     <value>It is impossible to call the provided strongly-typed predicate due to the use of a type matcher. Provide a weakly-typed predicate with two parameters (object, Type) instead.</value>
   </data>
+  <data name="ConditionalSetupsAreNotVerifiable" xml:space="preserve">
+    <value>This call to 'Verifiable' will have no effect because conditional setups are ignored by both 'Verify' and 'VerifyAll'. This might indicate an error in your code.</value>
+  </data>
 </root>

src/Moq/Setup.cs

@@ -7,6 +7,8 @@
 using System.Reflection;
 using System.Text;
 
+using Moq.Properties;
+
 namespace Moq
 {
 	internal abstract class Setup : ISetup
@@ -86,6 +88,11 @@ public void MarkAsOverridden()
 
 		public void MarkAsVerifiable()
 		{
+			if (this.IsConditional)
+			{
+				throw new InvalidOperationException(Resources.ConditionalSetupsAreNotVerifiable);
+			}
+
 			this.flags |= Flags.Verifiable;
 		}
 

tests/Moq.Tests/VerifyFixture.cs

@@ -1047,17 +1047,16 @@ public void CanVerifyMethodThatIsNamedLikeEventRemoveAccessor()
 		}
 
 		[Fact]
-		public void Verify_ignores_conditional_setups()
+		public void Verify_ignores_conditional_setups_so_calling_Verifiable_is_a_user_error()
 		{
 			var mock = new Mock<IFoo>();
-			mock.When(() => true).Setup(m => m.Submit()).Verifiable();
+			var setup = mock.When(() => true).Setup(m => m.Submit());
 
-			var exception = Record.Exception(() =>
-			{
-				mock.Verify();
-			});
-
-			Assert.Null(exception);
+			// Conditional setups are completely ignored by `Verify[All]`.
+			// Making such a setup verifiable is therefore a no-op, but
+			// may be indicative of the user making an incorrect assumption;
+			// best to warn the user so they revise their code:
+			Assert.Throws<InvalidOperationException>(() => setup.Verifiable());
 		}
 
 		[Fact]