BaseTest.cs

/*
In Xunit, NUnit or Test projects, inherit this class to avoid null exception
due to null assembly attributes when using  CommandLineParser library
*/

public class BaseTest
	   {
		   public BaseTest()  
		  {  
		//in  Full Framework NET4x only,   because no appdomain in netcore			
		#if NET45|NET461|NET472      
			/* Preparing test start */  
			Assembly assembly = Assembly.GetCallingAssembly();  

			AppDomainManager manager = new AppDomainManager();  
			FieldInfo entryAssemblyfield = manager.GetType().GetField("m_entryAssembly", BindingFlags.Instance | BindingFlags.NonPublic);  
			entryAssemblyfield.SetValue(manager, assembly);  

			AppDomain domain = AppDomain.CurrentDomain;  
			FieldInfo domainManagerField = domain.GetType().GetField("_domainManager", BindingFlags.Instance | BindingFlags.NonPublic);  
			domainManagerField.SetValue(domain, manager);  
			/* Preparing test end */  
		#endif
		} 
	  }