c# - How to unittest value depends on MessageBox? -

i use nunit test unit , have method:

class abc {     private int a;     public void mymethod()     {          if(messagebox.show("sure?", "title", messageboxbuttons.yesno) == dialogresult.yes)              = 1;          else              = 0;     } } 

how write nunit test method? sorry english. thank much.

the usual solution mock messagebox class , simulate show method returns. since it's static method, requires additional work , modifications in code. here's possible solution:

create class encapsulates show method:

public class mymessagebox {     public virtual dialogresult show(string text, string caption, messageboxbuttons buttons) {         return messagebox.show(text, caption, buttons);     } } 

then modify code use class:

class abc {     internal int a;     private readonly mymessagebox messagebox;      public abc(mymessagebox messagebox) {         this.messagebox = messagebox;     }      public void mymethod() {         if (messagebox.show("sure?", "title", messageboxbuttons.yesno) == dialogresult.yes)             = 1;         else             = 0;     } } 

after that, can write tests mock mymessagebox class. i'm using nsubstitute in example below:

[test] public void test() {     mymessagebox messagebox = substitute.for<mymessagebox>();     messagebox.show("sure?", "title", messageboxbuttons.yesno).returns(dialogresult.yes);      abc abc = new abc(messagebox);     abc.mymethod();      assert.areequal(1, abc.a); } 

that's 1 way it. it's decide if it's worth effort or not.