Mocking an interface derived from IList to pass it to Should().BeEquivalentTo()

Question

I am currently testing a method that returns an instance of the IBuilding interface defined like this:

public interface IBuilding
{
    public string Name { get; set; }
    public IBuildingZones Zones { get; set; }
}

public interface IBuildingZones: IList<IBuildingZone> 
{ 
    public void SortByElevation();
}

public interface IBuildingZone
{
    public string Name { get; set; }
    public double Elevation { get; set; } 
}

Testing for the Name value is quite easy, but I'm struggling with the best way to test for the Zones to contain a given set of values. Ideally, I would write this:

    building.Zones.Should().BeEquivalentTo(
        {
            { "garage", 0 },
            { "living_room", 10 },
            { "master bedroom", -4.2 }
        }
    ); 

But this obviously does not compile.

The assembly where IBuilding is defined has public classes that implement IBuildingZone and IBuildingZones so I can use them like this:

    var expectedZones = new BuildingZones
    {
        new BuildingZone("garage", 0),
        new BuildingZone("living_room", 10),
        new BuildingZone("master_bedroom", -4.2)
    };
    building.Zones.Should().BeEquivalentTo(expectedZones);

but I'm not too happy to use classes from the assembly under test to be able to test it, especially when all that is needed are interfaces.

This is why I went looking for a way to mock expectedZones using the Moq framework but I'm a bit stuck trying to find a lean syntax for this.

Any suggestion is most welcome.

Answer 1

You can use anonymous objects to avoid using the types under test.

var expected = new[]
{
   new { Name = "garage", Elevation = 0.0 },
   new { Name = "living_room", Elevation = 10.0 },
   new { Name = "master bedroom", Elevation = -4.2 }
};

building.Zones.Should().BeEquivalentTo(expected);