c# - Unit test for a Web API method without any injected dependency -

i have method in web api project , since it's pretty simple , there no injected dependency , deals concrete posted object, i'm not sure how create unit test it. there in design of below code change make more test-friendly?

public class homecontroller : apicontroller {     public httpresponsemessage post(rootobject root)     {         httpresponsemessage httpresponse;          return trycreateresponse(root, out httpresponse) ? httpresponse : request.createerrorresponse(httpstatuscode.internalservererror, "an unhandled exception occurred on server.");     }      private bool trycreateresponse(rootobject root, out httpresponsemessage httpresponse)     {         var success = false;         httpresponse = null;         try         {             var creator = (modelstate.isvalid)?                  new okresponsecreator(root) ihttpresponsecreator:                  new badreqeuestresponsecreator(applicationsettings.httpbadrequesterrormessage);              var abstracthttpresponse = new responsecontext(creator).createhttpresponse();             httpresponse = request.createresponse(abstracthttpresponse.statuscode, abstracthttpresponse);              success = true;         }         catch         {             success = false;         }          return success;     } } 

start testing homecontroller.post fake rootobject , asserting expected result returned test.

although there no injected dependencies, method , extension class dependent on okresponsecreator, badreqeuestresponsecreator responsecontext , applicationsettings.

given extent of coupling of classes not obvious in example , dependencies, suggest start looking @ classes.

if initial test fails, can try cycle of refactoring , retesting make mentioned classes mockable can safely injected controller better testability.