Get name of currently executing test in JUnit 4

java

unit-testing

junit-4

logging

byAnton Shumikhin·Dec 5, 2024

To access the name of the executing test method in JUnit 4, use the TestName rule:

@Rule
public TestName testName = new TestName();

@Test
public void exampleTest() {
    String currentTest = testName.getMethodName();
   // Whoops! The test name just dropped, better pick it up!
}

When using testName.getMethodName() within your test methods, the current test name is returned.

Efficient logging and data management with JUnit 4 rules

To effectively conduct unit testing in JUnit 4, an understanding of the rules particularly TestName rule, is crucial. Test-specific operations, like logging and data loading, become simplified with the usage of the TestName rule which also enables the access to the current test's name.

Implement logging with SLF4J

To achieve a customized logging experience, integrate SLF4J with JUnit 4, as demonstrated:

private static final Logger logger = LoggerFactory.getLogger(MyTestClass.class);

@Rule
public TestName testName = new TestName();

@Before
public void logTestName() {
    logger.info("Next Contestant : {}", testName.getMethodName());
}

Now, every time a test method runs, its name is logged, making our life easy when numerous tests are dancing around.

Mastering data-driven testing

By creating a strong binding between test methods and resource names, we can ensure a method-specific data loading process:

@Test
public void exampleTest() {
    String currentTest = testName.getMethodName();
    InputStream testInput = getClass().getResourceAsStream(currentTest + ".data");
    // Need a byte to eat? Here, have a stream!
}

This ensures easier maintenance and scalability for data-driven tests even in big projects.

Handling method naming conflicts

While the TestName rule is definitely a power player, exercise caution while dealing with tests subclassing TestCase. Here, TestName might not play ball due to legacy structures. It's suggested to use alternatives such as Description methods or consider refactoring.

Using TestWatcher for advanced introspection

from JUnit 4.9, you can utilize the TestWatcher class for more advanced pre-test actions and introspection.

@Rule
public TestWatcher watchman = new TestWatcher() {
    @Override
    protected void starting(Description description) {
        logger.info("Test is about to start jogging: {}", description.getMethodName());
    }
};

@Test
public void exampleTest() {
    // Now, where was I...
}

starting method is triggered right before each test, allowing you to perform any custom pre-test actions.

Embracing JUnit 5

If you are eyeing JUnit 5, you'll be pleased to know about TestInfo injection that offers enhanced access to test metadata :

@Test
public void exampleTest(TestInfo testInfo) {
    System.out.println("Display name: " + testInfo.getDisplayName());
    // Who am I? Ah, yes. That's me!
}