这是对适配器模式的正确使用吗？ 我无法实例化该对象？

Question

I am using C# with Unity3D.

There is an object type called Transform that I cannot directly instantiate.

I want to do some unit testing on a function that uses Transform.

Is this the correct way to do it?

Use the adapter pattern by:

• creating a class (TransformAdapter) that has the same functionality as Transform
• (when running for real) extending TransformAdapter, with a class called UnityTransform, that holds a Transform and just forwards on any functionality to Transform.
• (when running in unit test) extending TransformAdapter, with a class caled MockTransform, that just holds values set by my unit test.

Update:

It appears that in many situations, I don't need to create abstract classes to mock out the objects, as I can instantiate the objects from unit tests if I run the unit tests from the Unity3d Unit Testing window. I cannot instantiate the objects if running the tests from MonoDevelop.

Answer 1

Unity3D doesn't really allow you to use your "normal" design patterns because of certain limitations, especially with it's internal serialization.

But specific to your case, in Unity3D a transform cannot exist without a GameObject, and vice-versa. Just use new GameObject("Insert Name Here") in conjunction with GetComponent() on the new transform. You could write a small factory to do this.