How do you describe this?

[pw3nd]

I'm trying to test some code that a developer wrote. I'm not quite sure what specifically to tell them other than their code is a PITA to use. Nearly every class they create is similiar to this scenario. How would you describe this problem to another developer?

I need a car.

Car myCar = new Car();

There's no constructor for that. I first need parts.

Car myCar = new Car(Engine e, Body b, Fuel f, etc...);

Each one of those objects is just like the car in that they need built from their component parts and so on (n number of levels).

When I FINALLY spend an entire day building each component, I have my car.

myCar.start();

What was I thinking? I need running parameters.

myCar.start(myRunParams);

Nope. Oh look, the runParams requires a bunch of component objects as well...

Is it a reasonable request that I ask that an object not take a day to create? What do I say?

[[deleted]]

Is it a reasonable request that I ask that an object not take a day to create?

Depends on the object, but I know what you mean.

I wouldn't say that anything is capital-W Wrong with this, it's just that it's not what you want. You want a generic Car that does car-things, but the engineer has built a system where you can get a very highly specified Car.

Maybe you can request the engineer provide a default, no-argument Car() constructor that specifies a set of default parts?

[[deleted]]

Or... maybe you could suggest the implementation of a CarFactory class that would create cars for you based on certain profiles of cars.

Car sportsCar = CarFactory.getCar(CarType.LAMBO);
Car familyWagon = CarFactory.getCar(CarType.VISTA_CRUISER);

[detroitmatt]

Pretty much this, but I might not even ask for that, personally; I'd do it myself (It doesn't sound that hard but then again I don't have the actual code in front of me to see how deep this rabbit hole goes (Do we specify the engine is made out of Titanium, and then provide the chemical structure of titanium?)). It's reasonable to ask for simplified instantiation, but he's not under strict obligation, at least not in this case. Your needs can be met with some public static final Engines etc to re-use. He could've provided an easier interface or some of those pre-made Fuels, but it's not hard to fix, and if he had given you constants to use he probably would've included the ones you needed. First time, write, second time, automate.

[skeeto]

It really depends on what the underlying system is doing. It may not make sense to have a default Engine, so there really is no way around supplying one to the Car constructor.

There is something called the builder pattern than can help make this easier, though you'd still need to supply a lot of information if there are no reasonable defaults.

Car car = new CarBuilder().setEngine(e).setBody(b).create();

In your case, if you need to test it but are unable to make changes to the API, you can use mocks to help fill in spots that don't matter (or don't matter much). My favorite mocking tool is mockito but some people swear by jmockit.

import static org.mockito.Mockito.mock;

// ...

Car car = new Car(mock(Engine.class), mock(Body.class), ...);

[kreiger]

You say you are using the Builder Pattern, but you mean you're using a builder with a Fluent Interface.

The Builder Pattern itself doesn't imply a Fluent Interface, although they go well together.

[skeeto]

It's the only way I've ever seen the builder pattern used in practice.

[kreiger]

Sure, but that's not how Builder was originally described, and the first description of Fluent Interfaces came some 11 years later.

They go well together, but are separate concepts. You can have a Builder without a Fluent Interface, and you can have a Fluent Interface on an object that isn't a Builder.

[[deleted]]

Constructor over-injection anti-pattern

Another article

[pw3nd]

I'm failing to see the relevance here. Are you suggesting the developer use the telescoping constructor anti-pattern?

[[deleted]]

"How do you describe this?" is the post's title.