package org.apidesign.singletons.usage;

 import org.apidesign.singletons.api.DialogDisplayer;

 import org.junit.BeforeClass;

 import org.junit.Test;

 import org.netbeans.junit.MockServices;

 import static org.junit.Assert.*;

 public class MainTest {

     public MainTest() {

     }

     @BeforeClass

     public static void setUpClass() throws Exception {

         MockServices.setServices(MockDialogDisplayer.class);

     }

     @Test

     public void testMainAsksAQuestion() {

         assertNull("No question asked yet", MockDialogDisplayer.askedQuery);

         Main.main(new String[0]);

         assertNotNull("main code asked our Mock displayer", MockDialogDisplayer.askedQuery);

     }

     public static final class MockDialogDisplayer extends DialogDisplayer {

         static String askedQuery;

         @Override

         public boolean yesOrNo(String query) {

             askedQuery = query;

             return false;

         }

     }

 }