Get name of currently executing test in JUnit 4

问题:

In JUnit 3, I could get the name of the currently running test like this:

public class MyTest extends TestCase
{
    public void testSomething()
    {
        System.out.println("Current test is " + getName());
        ...
    }
}

which would print "Current test is testSomething".

Is there any out-of-the-box or simple way to do this in JUnit 4?

Background: Obviously, I don't want to just print the name of the test. I want to load test-specific data that is stored in a resource with the same name as the test. You know, convention over configuration and all that.

回答1:

JUnit 4.7 added this feature it seems using TestName-Rule. Looks like this will get you the method name:

import org.junit.Rule;

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());
    }
}

回答2:

JUnit 4.9.x and higher

Since JUnit 4.9, the TestWatchman class has been deprecated in favour of the TestWatcher class, which has invocation:

@Rule
public TestRule watcher = new TestWatcher() {
   protected void starting(Description description) {
      System.out.println("Starting test: " + description.getMethodName());
   }
};

JUnit 4.7.x - 4.8.x

The following approach will print method names for all tests in a class:

@Rule
public MethodRule watchman = new TestWatchman() {
   public void starting(FrameworkMethod method) {
      System.out.println("Starting test: " + method.getName());
   }
};

回答3:

Consider using SLF4J (Simple Logging Facade for Java) provides some neat improvements using parameterized messages. Combining SLF4J with JUnit 4 rule implementations can provide more efficient test class logging techniques.

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.MethodRule;
import org.junit.rules.TestWatchman;
import org.junit.runners.model.FrameworkMethod;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class LoggingTest {

  @Rule public MethodRule watchman = new TestWatchman() {
    public void starting(FrameworkMethod method) {
      logger.info("{} being run...", method.getName());
    }
  };

  final Logger logger =
    LoggerFactory.getLogger(LoggingTest.class);

  @Test
  public void testA() {

  }

  @Test
  public void testB() {

  }
}

回答4:

In JUnit 5 there is TestInfo injection which simplifies test meta data providing to test methods. For example:

@Test
@DisplayName("This is my test")
@Tag("It is my tag")
void test1(TestInfo testInfo) {
    assertEquals("This is my test", testInfo.getDisplayName());
    assertTrue(testInfo.getTags().contains("It is my tag"));
}

See more: JUnit 5 User guide, TestInfo javadoc.

回答5:

A convoluted way is to create your own Runner by subclassing org.junit.runners.BlockJUnit4ClassRunner.

You can then do something like this:

public class NameAwareRunner extends BlockJUnit4ClassRunner {

    public NameAwareRunner(Class<?> aClass) throws InitializationError {
        super(aClass);
    }

    @Override
    protected Statement methodBlock(FrameworkMethod frameworkMethod) {
        System.err.println(frameworkMethod.getName());
        return super.methodBlock(frameworkMethod);
    }
}

Then for each test class, you'll need to add a @RunWith(NameAwareRunner.class) annotation. Alternatively, you could put that annotation on a Test superclass if you don't want to remember it every time. This, of course, limits your selection of runners but that may be acceptable.

Also, it may take a little bit of kung fu to get the current test name out of the Runner and into your framework, but this at least gets you the name.

回答6:

Try this instead:

public class MyTest {
        @Rule
        public TestName testName = new TestName();

        @Rule
        public TestWatcher testWatcher = new TestWatcher() {
            @Override
            protected void starting(final Description description) {
                String methodName = description.getMethodName();
                String className = description.getClassName();
                className = className.substring(className.lastIndexOf('.') + 1);
                System.err.println("Starting JUnit-test: " + className + " " + methodName);
            }
        };

        @Test
        public void testA() {
                assertEquals("testA", testName.getMethodName());
        }

        @Test
        public void testB() {
                assertEquals("testB", testName.getMethodName());
        }
}

The output looks like this:

Starting JUnit-test: MyTest testA
Starting JUnit-test: MyTest testB

NOTE: This DOES NOT work if your test is a subclass of TestCase! The test runs but the @Rule code just never runs.

回答7:

JUnit 4 does not have any out-of-the-box mechanism for a test case to get it’s own name (including during setup and teardown).

回答8:

Based on the previous comment and further considering I created an extension of TestWather which you can use in your JUnit test methods with this:

public class ImportUtilsTest {
    private static final Logger LOGGER = Logger.getLogger(ImportUtilsTest.class);

    @Rule
    public TestWatcher testWatcher = new JUnitHelper(LOGGER);

    @Test
    public test1(){
    ...
    }
}

The test helper class is the next:

public class JUnitHelper extends TestWatcher {
private Logger LOGGER;

public JUnitHelper(Logger LOGGER) {
    this.LOGGER = LOGGER;
}

@Override
protected void starting(final Description description) {
    LOGGER.info("STARTED " + description.getMethodName());
}

@Override
protected void succeeded(Description description) {
    LOGGER.info("SUCCESSFUL " + description.getMethodName());
}

@Override
protected void failed(Throwable e, Description description) {
    LOGGER.error("FAILURE " + description.getMethodName());
}
}

Enjoy!

回答9:

String testName = null;
StackTraceElement[] trace = Thread.currentThread().getStackTrace();
for (int i = trace.length - 1; i > 0; --i) {
    StackTraceElement ste = trace[i];
    try {
        Class<?> cls = Class.forName(ste.getClassName());
        Method method = cls.getDeclaredMethod(ste.getMethodName());
        Test annotation = method.getAnnotation(Test.class);
        if (annotation != null) {
            testName = ste.getClassName() + "." + ste.getMethodName();
            break;
        }
    } catch (ClassNotFoundException e) {
    } catch (NoSuchMethodException e) {
    } catch (SecurityException e) {
    }
}

回答10:

@ClassRule
public static TestRule watchman = new TestWatcher() {
    @Override
    protected void starting( final Description description ) {
        String mN = description.getMethodName();
        if ( mN == null ) {
            mN = "setUpBeforeClass..";
        }

        final String s = StringTools.toString( "starting..JUnit-Test: %s.%s", description.getClassName(), mN );
        System.err.println( s );
    }
};

回答11:

I'd suggest you decouple the test method name from your test data set. I would model a DataLoaderFactory class which loads/caches the sets of test data from your resources, and then in your test case cam call some interface method which returns a set of test data for the test case. Having the test data tied to the test method name assumes the test data can only be used once, where in most case i'd suggest that the same test data in uses in multiple tests to verify various aspects of your business logic.

回答12:

You can achieve this using Slf4j and TestWatcher

private static Logger _log = LoggerFactory.getLogger(SampleTest.class.getName());

@Rule
public TestWatcher watchman = new TestWatcher() {
    @Override
    public void starting(final Description method) {
        _log.info("being run..." + method.getMethodName());
    }
};

回答13:

In JUnit 5 TestInfo acts as a drop-in replacement for the TestName rule from JUnit 4.

From the documentation :

TestInfo is used to inject information about the current test or container into to @Test, @RepeatedTest, @ParameterizedTest, @TestFactory, @BeforeEach, @AfterEach, @BeforeAll, and @AfterAll methods.

To retrieve the method name of the current executed test, you have two options : String TestInfo.getDisplayName() and Method TestInfo.getTestMethod().

To retrieve only the name of the current test method TestInfo.getDisplayName() may not be enough as the test method default display name is methodName(TypeArg1, TypeArg2, ... TypeArg3).
Duplicating method names in @DisplayName("..") is not necessary a good idea.

As alternative you could use TestInfo.getTestMethod() that returns a Optional<Method> object.
If the retrieval method is used inside a test method, you don't even need to test the Optional wrapped value.

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.TestInfo;
import org.junit.jupiter.api.Test;

@Test
void doThat(TestInfo testInfo) throws Exception {
    Assertions.assertEquals("doThat(TestInfo)",testInfo.getDisplayName());
    Assertions.assertEquals("doThat",testInfo.getTestMethod().get().getName());
}