Use any mocking framework to create a fake/stub/mock for ICodeCamperUow
(below I am using NSubstitute):
[TestMethod]
public void GetRoomsTest()
{
// UOW we need to use
var fakeUOW = Substitute.For<ICodeCamperUow>();
// setting up room repository so that it returns a collection of one room
var fakeRooms = Substitute.For<IRepository<Room>>();
var fakeRoomsQueryable = new[]{new Room()}.AsQueryable();
fakeRooms.GetAll<Room>().Returns(fakeRoomsQueryable);
// connect UOW with room repository
fakeUOW.Rooms.Returns(fakeRooms);
var controller = new LookupsController(fakeUOW);
var result = controller.GetRooms().Any();
Assert.IsTrue(result);
}
Please consider reading The Art of Unit Testing which is a great book to learn about unit testing.