AmbiguousMatchException when setting up the property, that hides another one

[ishatalkin]

mock.Setup(m => m.Prop) throws AmbiguousMatchException in case that:

• Prop hides the property with new keyword;
• the hidden and the derived properties have different types;
• mocked object has the child class of the class, where the property was hidden.

You can repropduce the exception with the following code:

public class HidePropertyFixture
{
	public class A
	{
		public string Prop { get; }
	}

	public class B : A
	{
		// consider new keyword and the different type of property
		public new virtual int Prop { get; }
	}

	public class C : B
	{

	}

	[Fact]
	public void SetupsDerivedProperty()
	{
		// create the mock of C; mock of B works correct
		var mock = new Mock<C>();
		// the next line will throw AmbiguousMatchException 
		mock.Setup(m => m.Prop);
	}
}

Stacktrace:

System.Reflection.AmbiguousMatchException
   в System.RuntimeType.GetPropertyImpl(String name, BindingFlags bindingAttr, Binder binder, Type returnType, Type[] types, ParameterModifier[] modifiers)
   в System.Type.GetProperty(String name, BindingFlags bindingAttr)
   в Moq.ExpressionExtensions.GetReboundProperty(MemberExpression expression) в C:\Projects\github_moq\src\Moq\ExpressionExtensions.cs:строка 323
   в Moq.ExpressionExtensions.<Split>g__Split|4_1(Expression e, Expression& r, InvocationShape& p) в C:\Projects\github_moq\src\Moq\ExpressionExtensions.cs:строка 286
   в Moq.ExpressionExtensions.Split(LambdaExpression expression) в C:\Projects\github_moq\src\Moq\ExpressionExtensions.cs:строка 107
   в Moq.Mock.SetupRecursive[TSetup](Mock mock, LambdaExpression expression, Func`3 setupLast) в C:\Projects\github_moq\src\Moq\Mock.cs:строка 590
   в Moq.Mock.Setup(Mock mock, LambdaExpression expression, Condition condition) в C:\Projects\github_moq\src\Moq\Mock.cs:строка 527
   в Moq.Mock`1.Setup[TResult](Expression`1 expression) в C:\Projects\github_moq\src\Moq\Mock.Generic.cs:строка 407

Here is pull request that fixes the bug.

This bug is somewhat similar with #930, but here is the problem of Moq.

[stakx]

Thanks for the bug fix... Looks good to me! Apart from the request below, could you please also add an entry to the CHANGELOG.md?

 The format is loosely based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).


+## Unreleased
+
+#### Fixed
+
+* <description of your bug fix> (@ishatalkin, #939)
+
+
 ## 4.13.0 (2019-08-31)

Thanks!

[ishatalkin]

Ok! I'll do the stuff tomorrow. ср, 16 окт. 2019 г., 20:23 stakx <notifications@github.com>:

…

***@***.**** requested changes on this pull request. Thanks for the bug fix... Looks good to me! Apart from the request below, could you please also add an entry to the CHANGELOG.md? The format is loosely based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/). +## Unreleased++#### Fixed++* <description of your bug fix> ***@***.***, #939)++ ## 4.13.0 (2019-08-31) Thanks! ------------------------------ In src/Moq/ExpressionExtensions.cs <#939 (comment)>: > @@ -320,7 +320,9 @@ internal static PropertyInfo GetReboundProperty(this MemberExpression expression // we "upgrade" to the derived property. if (property.DeclaringType != expression.Expression.Type) { - var derivedProperty = expression.Expression.Type.GetProperty(property.Name, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance); + var derivedProperty = expression.Expression.Type + .GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance) + .SingleOrDefault(p => p.Name == property.Name && p.PropertyType == property.PropertyType); Could you please rewrite this query as follows?: var derivedProperty = expression.Expression.Type .GetMember(property.Name, MemberTypes.Property, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance) .Cast<PropertyInfo>() .SingleOrDefault(p => p.PropertyType == property.PropertyType); This should be more efficient as the filtering by name happens earlier (inside System.Reflection). — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#939>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AC2TXXKUNILRHYZVO5CQZ7DQO5E2HANCNFSM4JBGX3EA> .

[ishatalkin]

@stakx, I've made the changes. Is it OK now?

[stakx]

Looks good to me.

Btw. it appears that you are using a different email address in your commits than on GitHub, so your commits won't be linked to your profile when viewed on GitHub. If you want to fix that, now would be a good time.

Otherwise I'll merge your PR tonight (in approx. 8 hours).

[ishatalkin]

Btw. it appears that you are using a different email address in your commits than on GitHub, so your commits won't be linked to your profile when viewed on GitHub. If you want to fix that, now would be a good time.

Added secondary e-mail address to my profile. Feel free to merge the PR

[stakx]

🚀

Thank you for contributing, @ishatalkin!