Testing private fields with Unity Test Tools

Hello everybody,

I'm currently trying to get into the Unity Test Tools. After having read and watched some tutorials and I'm now trying to get them to work in a small sample project. But I don't know how to test private methods.

E.g. I want to check, if the health of the player is set correctly in the Awake function.

Code (CSharp):

1. [Test]
2. public void AssertAwake()
3. {
4.     Health health = new Health();
5.    
6.     Assert.That(health._currentHitPoints == health._initialHitPoints);
7. }

But both members are private, so this obviously does not work. But how can I test private methods / use private members during tests? The only solutions I found are not working with Unity objects.

And btw, Unity warns me that "You are trying to create a MonoBehaviour using the 'new' keyword. This is not allowed. MonoBehaviours can only be added using AddComponent(). Alternatively, your script can inherit from ScriptableObject or no base class at all". Should I care about that or just ignore it, as this is just a unit test?

 

Thank you for taking the time to reply!

Yes I can, but wouldn't that break the encapsulation principle? In my recent test project (which is a very simple project I'm using solely to get familiar with the Unity Test Tools) the Health script is meant to handle the object health all by itself. When another object able to damage my object wants to damage it, it calls the method TakeDamage(int damage) from the interface. Anything else is done internally in the Health-component, which is why I thought it would be good design to hide health from the world. But that makes it difficult to check, if the TakeDamage-function actually changed health correctly.

Ok, this seems to work, but only for nullable types (Visual Studio tells me so, DuckDuckGo confirmed it ;-) ). Do you kow how to make this work with non-nullable types?

OMG, I'm so stupid (or was too tired)... now that you say it, I remember reading it on the Unity Blog... :-D

Edit: Removed the off-topic parts, which I'll put into a separate thread.

 

Sorry for digging out this old thread but I found interesting ways to achieve that.

I make public accessors that are only available within the context of the tests by using preprocessor macros.

Code (CSharp):

1. class Health
2. {
3. ...
4. #if UNITY_INCLUDE_TESTS
5.     // Accessors for testing purpose
6.     public int CurrentHitPoints_test()
7.     {
8.         return _currentHitPoints;
9.     }
10.     public int InitialHitPoints_test()
11.     {
12.         return _initialHitPoints;
13.     }
14. #endif
15. }

You can find them in your test assembly definition asset and change them as well.


You can even separate those test methods in another file by using partial declaration if you don’t want to mess your logic with your tests.