Package org.junit.rules

Class TestWatcher

  • All Implemented Interfaces:
    TestRule
    Direct Known Subclasses:
    TestName
    public abstract class TestWatcher
extends java.lang.Object
implements TestRule
    TestWatcher is a base class for Rules that take note of the testing action, without modifying it. For example, this class will keep a log of each passing and failing test: 
     public static class WatchmanTest {
  private static String watchedLog;

  @Rule(order = Integer.MIN_VALUE)
  public TestWatcher watchman= new TestWatcher() {
      @Override
      protected void failed(Throwable e, Description description) {
          watchedLog+= description + "\n";
      }

      @Override
      protected void succeeded(Description description) {
          watchedLog+= description + " " + "success!\n";
         }
     };

  @Test
  public void fails() {
      fail();
  }

  @Test
  public void succeeds() {
     }
 }

    It is recommended to always set the order of the TestWatcher to Integer.MIN_VALUE so that it encloses all other rules. Otherwise it may see failed tests as successful and vice versa if some rule changes the result of a test (e.g. ErrorCollector or ExpectedException).

    Since:
    4.9