c# - Can I mock object which is impossible to instantiate? -

i using com library in c# bound particular hardware , doesn't work without it. on development/testing computer don't have hardware. method using library looks this:

using hwsysmanagerlib; bool processbias(hwsysmanager systemmanager, string hwpath) {     int handle = systemmanager.openconfiguration(hwpath);     ...     // magic goes here     // return result } 

the question is, can mock hwsysmanager test method , how? there few methods in hwsysmanager , wouldn't problem simulate functionality test. tiny example great on how mock it, if it's possible @ all.

you can use adapter pattern here.

create interface named ihwsysmanager

public interface ihwsysmanager {     int openconfiguration(string hwpath); } 

the real implementation class delegates work library:

public class hwsysmanagerimpl : ihwsysmanager {     private hwsysmanager _hwsysmanager; //initialize constructor      public int openconfiguration(string hwpath)     {         return _hwsysmanager.openconfiguration(hwpath);     } } 

use interface in code this:

bool processbias(ihwsysmanager systemmanager, string hwpath) {     int handle = systemmanager.openconfiguration(hwpath);     ...     // magic goes here     // return result } 

now can mock ihwsysmanager interface mock frameworks or can create stub class yourself.