c# - UnitTest ApiController with ExceptionFilterAttribute -

i'm trying unittest controller exception catch exceptionfilterattribute , launched httpresponseexception.

controller

[exceptionfilters] //exceptionfilterattribute public class elevecontroller : apicontroller {    private igpirepository _gpirepository;    public elevecontroller(igpirepository gpirepository)   {      _gpirepository = gpirepository;   }    [httpget]   [route("{fiche:int}/grouperepere")]   public grouperepere grouperepere(int fiche) //this im trying test   {      gpiservice service = new gpiservice(_gpirepository);      return service.get(fiche); //throw argumentnullexception when fiche == 0   } } 

exceptionfilter

public class exceptionfilters : exceptionfilterattribute {   public override void onexception(httpactionexecutedcontext context)   {      if (context.exception notimplementedexception)      {         context.response = new httpresponsemessage(httpstatuscode.notimplemented);      }      else if (context.exception argumentnullexception)      {         context.response = new httpresponsemessage(httpstatuscode.badrequest)         {            content = new stringcontent(string.format("argument \"{0}\" null or invalid", ((argumentnullexception)context.exception).paramname)),            reasonphrase = "argument null or invalid"         };      }   } 

and test:

  private igpirepository _gpirepository;   private mock<icallapi> _callapi;   private elevecontroller _controller;    [testinitialize]   public void initialize()   {      _callapi = new mock<icallapi>();      _gpirepository = new gpirepository(_callapi.object);      _controller = new elevecontroller(_gpirepository);   }    [testmethod]   public void elevecontroller__grouperepere_withbadfiche_400badrequest()   {      string nogroupe = "111";      int fiche = 0;      try      {         grouperepere gp = _controller.grouperepere(fiche);          assert.fail();      }      catch (exception e)      {         assert.istrue(e httpresponseexception); // not working --> argumentnullexception      }   } 

the problem e still argumentnullexception. when go on debug, doesn't reach exceptionfilter class

am missing something? thanks.

your test directly against controller. exceptionfilterattribute depends on server.(remember: attributes metadata)

the way test behavior use iis server or selfhost server, raise server in test class , send request:

[testinitialize] public void initialize() {     _callapi = new mock<icallapi>();     _gpirepository = new gpirepository(_callapi.object);     //initialize server    //set _gpirepository dependency , etc.. } [testmethod] public void elevecontroller__grouperepere_withbadfiche_400badrequest() {     //configure request     var result = client.executeasget<grouperepere>(<your request>);      assert.areequal(httpstatuscode.badrequest,result.statuscode); } 

in opinion shouldn't error code unless controller apart of public api.(the reason simple kind of tests simple break, thay slow , thay use expensive resources) if controller part public api should test through acceptance tests, verify nothing override expected behavior.

if still want test behavior i'd offer alternative way test it:

1. create ut against exceptionfilters.
2. create ut verifies method has exceptionfilters attribute

for example:

[testmethod] public void grouperepere_hasexceptionfiltersattribute()  {     var attribute = typeof (unittest2).getmethod("grouperepere").getcustomattributes(true);      foreach (var att in attribute)     {         if(att.gettype() typeof(exceptionfilters))         {             return;         }     }     assert.fail(); } 

pros: it' fast, not easy break, doesn't use expensive reasorces.

cons: in production setting override expected behavior.