How to do it...

To unit test a health script class, follow these steps:

1. Create a new 3D Unity project.
2. In the Package Manager panel window, you have the latest version of the Test Framework package installed.
3. Create a new folder named _Scripts. 
4. Inside your _Scripts folder, create a new Health.cs C# script class containing the following:

    using UnityEngine;
    using System.Collections;
 
     public class Health
     {
         private float _health = 1;
 
         public float GetHealth()
         {
             return _health;
         }
 
         public bool AddHealth(float heathPlus)
         {
             if(heathPlus > 0){
                 _health += heathPlus;

                 // ensure never more than 1
                 if(_health > 1) _health = 1;
                 return true;
             } else {
                 return false;
             }
         }
 
         public bool KillCharacter()
         {
             _health = 0;
         ...