public void GetOrdersByCustomerId() { // Arrange var orders = new EnumerableQuery <Orders>( new List <Orders> { new Orders { OrderID = 10248, CustomerID = "VINET", Customers = new Customers { CustomerID = "VINET" } }, new Orders { OrderID = 10249, CustomerID = null, Customers = null } }); // Act var result = orders.GetOrdersByCustomerId("VINET"); // Assert result.ShouldBeEquivalentTo(new List <Orders> { new Orders { OrderID = 10248, CustomerID = "VINET", Customers = new Customers { CustomerID = "VINET" } } }); }