Rhino Mock Parameter Inspection ... Is There a Better Way?

Question

I'm using Rhino Mocks 3.5 to mock a service method call which takes 2 parameters and I want to make sure a propery on an object is being set correctly.

// Method being tested
void UpdateDelivery( Trade trade )
{
    trade.Delivery = new DateTime( 2013, 7, 4 );
    m_Service.UpdateTrade( trade, m_Token ); // mocking this
}

Here's a portion of my code (which works)

service, trade, token declared / new'd up ... etc.
...

using ( m_Mocks.Record() )
{
    Action<Trade, Token> onCalled = ( tradeParam, tokenParam ) =>
            {
                // Inspect / verify that Delivery prop is set correctly
                // when UpdateTrade called
                Assert.AreEqual( new DateTime( 2013, 7, 4 ), tradeParam.Delivery );                     
            };

    Expect.Call( () => m_Service.UpdateTrade( Arg<Trade>.Is.Equal( trade ), Arg<Token>.Is.Equal( token ) ) ).Do( onCalled );
}

using ( m_Mocks.Playback() )
{
    m_Adjuster = new Adjuster( service, token );
    m_Adjuster.UpdateDelivery( trade );
}

Is there a better, more concise, straightfoward way to test this using Rhino Mocks? I've seen posts where Contraints are used but I'm not a fan of identifying properties / value by string names.

Answer 1

You can do the following:

Expect.Call(() => m_Service.UpdateTrade(
    Arg<Trade>.Matches(t => t.Delivery.Equals(new DateTime(2013, 7, 3))),
    Arg<Token>.Is.Anything)
);

Please also note, if you are not going to validate token parameter in this tests, then you can use Is.Anything constraint for it.

---

Note:

RhinoMocks 3.5 and .NET4+ throw an AmbiguousMatchException when using the Matches(Expression<Predicate<..>>) overload. If it is not possible to update to RhinoMocks 3.6 (there are reasons), one can still use the Matches(AbstractConstraint) overload as so:

 Arg<Trade>.Matches(
   Property.Value("Delivery", new DateTime(2013, 7, 3)))

or:

 Arg<Trade>.Matches(
   new PredicateConstraint<DateTime>(
     t => t.Delivery.Equals(new DateTime(2013, 7, 3))))