Given mock.SetupGet(o => o.Property).CallBase(), strict mocks throw, demanding that the setup provide a return value

[stakx]

Strict mocks verify that setups for property getters actually specify some return value. (For the same reason that C# enforces non-void methods to return a value if they don't throw an exception first, so that verification is perfectly reasonable.)

The following test fails:

public class Foo
{
    public virtual bool BooleanProperty => true;
}

[Fact]
var mock = new Mock<Foo>(MockBehavior.Strict);
mock.SetupGet(_ => _.BooleanProperty).CallBase();
Assert.True(mock.Object.BooleanProperty);

Moq.MockException: Foo.BooleanProperty invocation failed with mock behavior Strict.
Invocation needs to return a value and therefore must have a corresponding setup that provides it.
at Moq.ExecuteCall.ThrowIfReturnValueRequired(IProxyCall call, ICallContext invocation)
at Moq.ExecuteCall.HandleIntercept(ICallContext invocation, InterceptorContext ctx, CurrentInterceptContext localctx)
at Moq.Interceptor.Intercept(ICallContext invocation)
at Moq.Proxy.CastleProxyFactory.Interceptor.Intercept(IInvocation invocation)
at Castle.DynamicProxy.AbstractInvocation.Proceed()
at Castle.Proxies.FooProxy.get_BooleanProperty()
at …

However, it should pass because BooleanProperty has been set up to return a value; not an explicitly specified value (.Returns(…)), but whatever the base class' (Foo's) BooleanProperty returns (.CallBase()).

[stakx]

This will be fixed in the next release of Moq (version > 4.7.99).