package org.junit.tests.running.classes;
   
   import static org.junit.Assert.assertEquals;
   import static org.junit.Assert.assertTrue;
   
   import org.junit.Test;
   import org.junit.runner.Description;
   import org.junit.runner.JUnitCore;
   import org.junit.runner.RunWith;
  import org.junit.runner.Runner;
  import org.junit.runner.notification.RunNotifier;
  
  public class RunWithTest {
  
      private static String log;
  
      public static class ExampleRunner extends Runner {
          public ExampleRunner(Class<?> klass) {
              log += "initialize";
          }
  
          @Override
          public void run(RunNotifier notifier) {
              log += "run";
          }
  
          @Override
          public int testCount() {
              log += "count";
              return 0;
          }
  
          @Override
          public Description getDescription() {
              log += "plan";
              return Description.createSuiteDescription("example");
          }
      }
  
      @RunWith(ExampleRunner.class)
      public static class ExampleTest {
      }
  
      @Test
      public void run() {
          log = "";
  
          JUnitCore.runClasses(ExampleTest.class);
          assertTrue(log.contains("plan"));
          assertTrue(log.contains("initialize"));
          assertTrue(log.contains("run"));
      }
  
      public static class SubExampleTest extends ExampleTest {
      }
  
      @Test
      public void runWithExtendsToSubclasses() {
          log = "";
  
          JUnitCore.runClasses(SubExampleTest.class);
          assertTrue(log.contains("run"));
      }
  
      public static class BadRunner extends Runner {
          @Override
          public Description getDescription() {
              return null;
          }
  
          @Override
          public void run(RunNotifier notifier) {
              // do nothing
          }
      }
  
      @RunWith(BadRunner.class)
      public static class Empty {
      }
  
      @Test
      public void characterizeErrorMessageFromBadRunner() {
          assertEquals(
                  "Custom runner class BadRunner should have a public constructor with signature BadRunner(Class testClass)",
                  JUnitCore.runClasses(Empty.class).getFailures().get(0)
                          .getMessage());
      }
  }