public async Task Handle_WhenInvoked_MustSaveNewOrder() { // Arrange var command = new CreateOrderCommandBuilder().Build(); var subject = CreateSubject(); // Act await subject.Handle(command); // Assert await repository.Received().Save( Arg.Is <Order>( o => o.Id == command.OrderId && o.GroupId == command.GroupId && o.SupplierId == command.SupplierId)); }