## Summary of Changes in version 4.7 ## ### Rules ### - Rules allow very flexible addition or redefinition of the behavior of each test method in a test class. Testers can reuse or extend one of the provided Rules below, or write their own. For more on this feature, see http://www.threeriversinstitute.org/blog/?p=155 - The TemporaryFolder Rule allows creation of files and folders that are guaranteed to be deleted when the test method finishes (whether it passes or fails): public static class HasTempFolder { @Rule public TemporaryFolder folder= new TemporaryFolder(); @Test public void testUsingTempFolder() throws IOException { File createdFile= folder.newFile("myfile.txt"); File createdFolder= folder.newFolder("subfolder"); // ... } } - ExternalResource is a base class for Rules (like TemporaryFolder) that set up an external resource before a test (a file, socket, server, database connection, etc.), and guarantee to tear it down afterward: public static class UsesExternalResource { Server myServer = new Server(); @Rule public ExternalResource resource = new ExternalResource() { @Override protected void before() throws Throwable { myServer.connect(); }; @Override protected void after() { myServer.disconnect(); }; }; @Test public void testFoo() { new Client().run(myServer); } } - The ErrorCollector Rule allows execution of a test to continue after the first problem is found (for example, to collect _all_ the incorrect rows in a table, and report them all at once): public static class UsesErrorCollectorTwice { @Rule public ErrorCollector collector= new ErrorCollector(); @Test public void example() { collector.addError(new Throwable("first thing went wrong")); collector.addError(new Throwable("second thing went wrong")); } } - Verifier is a base class for Rules like ErrorCollector, which can turn otherwise passing test methods into failing tests if a verification check is failed public static class ErrorLogVerifier() { private ErrorLog errorLog = new ErrorLog(); @Rule public MethodRule verifier = new Verifier() { @Override public void verify() { assertTrue(errorLog.isEmpty()); } } @Test public void testThatMightWriteErrorLog() { // ... } } - TestWatchman 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 public MethodRule watchman= new TestWatchman() { @Override public void failed(Throwable e, FrameworkMethod method) { watchedLog+= method.getName() + " " + e.getClass().getSimpleName() + "\n"; } @Override public void succeeded(FrameworkMethod method) { watchedLog+= method.getName() + " " + "success!\n"; } }; @Test public void fails() { fail(); } @Test public void succeeds() { } } - The TestName Rule makes the current test name available inside test methods: public class NameRuleTest { @Rule public TestName name = new TestName(); @Test public void testA() { assertEquals("testA", name.getMethodName()); } @Test public void testB() { assertEquals("testB", name.getMethodName()); } } - The Timeout Rule applies the same timeout to all test methods in a class: public static class HasGlobalTimeout { public static String log; @Rule public MethodRule globalTimeout = new Timeout(20); @Test public void testInfiniteLoop1() { log+= "ran1"; for(;;) {} } @Test public void testInfiniteLoop2() { log+= "ran2"; for(;;) {} } } - The ExpectedException Rule allows in-test specification of expected exception types and messages: public static class HasExpectedException { @Rule public ExpectedException thrown= ExpectedException.none(); @Test public void throwsNothing() { } @Test public void throwsNullPointerException() { thrown.expect(NullPointerException.class); throw new NullPointerException(); } @Test public void throwsNullPointerExceptionWithMessage() { thrown.expect(NullPointerException.class); thrown.expectMessage("happened?"); thrown.expectMessage(startsWith("What")); throw new NullPointerException("What happened?"); } } ### Timeouts ### - Tests that time out now show the stack trace of the test thread. ### Matchers ### - Due to typing incompatibilities, JUnit is still including the 1.1 release of hamcrest. This is not a change from 4.6, but is a change from pre-beta releases of 4.7. Due to this incompatibility, tests using Hamcrest 1.2 must still use the MatcherAssert.assertThat method from Hamcrest, not Assert.assertThat from JUnit. ### Docs ### - Javadocs now link to online JDK javadocs (bug 2090230) - Parameterized runner javadocs improved (bug 2186792) - Fixed Javadoc code sample for AfterClass (2126279) - Fixed Javadoc for assertArraysEqual(float[], float[]) ### Bug fixes ### - Fixed: BaseTestRunner.getTest() requires class to extend TestCase (1812200) - Fixed: Suite does not allow for inheritance in annotations (2783118) - Fixed: ParallelComputer skipped tests that took longer than 2 seconds