JUnit 5 Release Notes

SummaryGeneratingListener is now thread-safe and can handle concurrently failing tests.

For consistency with the rest of the JUnit Platform, the experimental LauncherDiscoveryListener is now an interface instead of an abstract class.

New test(Condition<Event>) and nestedContainer(Class<?>, Condition<Event>) methods in EventConditions that allow you to provide conditions for matching against test and nested container events when using the EngineTestKit. For example, test(displayName("my test")) can be used to match against a test whose display name is my test.

The junit-platform-jfr module now reports execution events for containers — for example, test classes.

The junit-platform-jfr module now reports test discovery events for the launcher and registered test engines.

Custom LauncherDiscoveryListener implementations can now be registered via Java’s ServiceLoader mechanism.

Documented constant value of ExclusiveResource.GLOBAL_KEY.

Instances of TestIdentifier and UniqueId now retain less memory because they no longer store String representations of unique IDs.

Improved ExclusiveResource handling: if a Node has only read locks and no read-write locks, then descendants are not forced into SAME_THREAD execution and can run concurrently.

Tools that make multiple calls to the Launcher API should now create a LauncherSession in order to allow for executing global setup and teardown code exactly once via the new LauncherSessionListener interface that can be registered via Java’s ServiceLoader mechanism.

New junit-platform-suite-engine to execute declarative test suites using the JUnit Platform Launcher.

Additional selectors in the suite API in the junit-platform-suite-api module.

InvocationInterceptor.interceptDynamicTest(Invocation<Void>, ExtensionContext) has been deprecated in favor of InvocationInterceptor.interceptDynamicTest(Invocation<Void>, DynamicTestInvocationContext, ExtensionContext) that provides access to the dynamic test executable via DynamicTestInvocationContext.getExecutable().

Top-level test classes can now be ordered by passing the fully-qualified name of a class implementing ClassOrderer as the value of the new junit.jupiter.testclass.order.default configuration parameter.

New assertInstanceOf() methods which produce better error messages comparable to those produced by assertThrows. These new methods serve as a replacement for assertTrue(obj instanceof X).

assertNull() failure messages now include the actual object’s type if the toString() implementation for the actual object returns null or "null". This avoids the generation of confusing failure messages such as expected <null> but was <null>.

Numeric literals used with @CsvSource or CsvFileSource can now be expressed using underscores as in some JVM languages, to improve readability of long numbers like 700_000_000.

CSV rows provided via @CsvSource may now start with a number sign (#).

New ignoreLeadingAndTrailingWhitespace attributes in @CsvSource and @CsvFileSource (set to true by default) to control whether or not to trim whitespace.

Dynamic tests now require less memory thanks to a number of improvements to internal data structures.

Documented constant values in org.junit.jupiter.api.parallel.Resources.

In parameterized tests with @MethodSource or @ArgumentSource, arguments can now have optional names (supplied via the new Named API). When the argument is included in the display name of an iteration, this name will be used instead of the value.

DynamicTests.stream() can now consume Named input and will use each name-value pair as the display name and value for each generated dynamic test (see User Guide for details).

The JUnit Vintage engine now requires less memory and allows for earlier garbage collection thanks to a number of improvements to internal data structures.

StringUtils.nullSafeToString() now returns "null" if the invocation of toString() on the supplied object returns null. Although this is an internal utility, the effect of this change may be witnessed by end users and test engine or extension authors.

Method scanForClassesInPackage(String) in ClasspathScanner now returns a valid list of class names when the package name is equal to the name of a module on the module path.

The legacy XML report now always includes container-level failures (e.g. from @BeforeAll Jupiter lifecycle methods).

If the toString() implementation of an argument passed to a @ParameterizedTest method returns null, the display name formatter for the parameterized test now treats the name of the corresponding argument as "null" instead of throwing an exception. This fixes a regression introduced in JUnit Jupiter 5.7.0.

Creator functions passed to ExtensionContext.Store.getOrComputeIfAbsent() are now only called once even if they throw an exception.

The user guide now explains Nested Tests in more detail.

New utility method in TestInstancePreDestroyCallback helps to ensure all test instances are processed when used in conjunction with @Nested tests.

JAVA_17 has been added to the JRE enum for use with JRE-based execution conditions.

The legacy reporting name of top-level test classes is now always their fully-qualified class name. Previously, a textual description was returned for JUnit 3 suites.