Testing MonoBehaviours in a Package

Hi! I'm working on a package.
It has MonoBehaviour scripts in it.
I'm trying to test these MB scripts.
I decided to setup Test Scenes with certain states, load them during the Test, and to assert results.

• I tried PlayMode Tests. To SceneManager.LoadScene and to assert results.
  The issue:
  Unity wants these Scenes to be added to BuildSettings.
  I cannot do this, because this is a package.
  
  
• I tried EditorTests with EditorSceneManager.OpenScene
  The issue:
  OpenScene requires a path to a scene, and it cannot find my scene in Packages folder
  
  
• Instead of scenes, I could Instantiate prefabs from my Tests folder. The issue: AssetDatabase cannot find assets in Packages folder.
  

The question!
How to setup Tests in a Package with several MonoBehaviours instantiated in a Scene-like or Prefab-like structure?

 

Forgive me if you've already explored this but Unity has a built in Testing framework: https://www.raywenderlich.com/9454-introduction-to-unity-unit-testing

Does this work for you? Not sure if being a package makes it not useable.

 

Hi PraetorBlue! Thanks.
Yes, I'm trying to apply Unity Testing framework to a Package.
For now, I'm gonna continue with PlayMode tests...
Maybe someone would come up with better approach to testing a package.