junit-team/junit5 · error · JUnitException

'ResourceLockTarget.CHILDREN' is not supported for methods.

Error message

'ResourceLockTarget.CHILDREN' is not supported for methods. Invalid method: <method>

What it means

Thrown by MethodBasedTestDescriptor.getExclusiveResourceCollector() when a test method is annotated with @ResourceLock whose target is ResourceLockTarget.CHILDREN. CHILDREN only makes sense on a container (class-level) descriptor because a method has no child tests, so the engine rejects it as a JUnitException.

Source

Thrown at junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/MethodBasedTestDescriptor.java:133

		Validatable.reportAndClear(this.methodInfo.discoveryIssues, reporter);
		DisplayNameUtils.validateAnnotation(getTestMethod(), //
			() -> "method '%s'".formatted(getTestMethod().toGenericString()), //
			// Use _declaring_ class here because that's where the `@DisplayName` annotation is declared
			() -> MethodSource.from(getTestMethod()), //
			reporter);
	}

	// --- Node ----------------------------------------------------------------

	@Override
	public ExclusiveResourceCollector getExclusiveResourceCollector() {
		// There's no need to cache this as this method should only be called once
		ExclusiveResourceCollector collector = ExclusiveResourceCollector.from(getTestMethod());

		if (collector.getStaticResourcesFor(CHILDREN).findAny().isPresent()) {
			String message = "'ResourceLockTarget.CHILDREN' is not supported for methods." + //
					" Invalid method: " + getTestMethod();
			throw new JUnitException(message);
		}

		return collector;
	}

	@Override
	public Function<ResourceLocksProvider, Set<ResourceLocksProvider.Lock>> getResourceLocksProviderEvaluator() {
		return enclosingInstanceTypesDependentResourceLocksProviderEvaluator(this::getEnclosingTestClasses,
			(provider, enclosingInstanceTypes) -> provider.provideForMethod(enclosingInstanceTypes, getTestClass(),
				getTestMethod()));
	}

	@Override
	protected Optional<ExecutionMode> getExplicitExecutionMode() {
		return getExecutionModeFromAnnotation(getTestMethod());
	}

	/**

View on GitHub (pinned to 956246301e)

Solutions

1. Move the @ResourceLock(target = CHILDREN) annotation from the method to the enclosing test class.
2. If the lock applies to the method itself, use the default target (or ResourceLockTarget.SELF).
3. Search the codebase for @ResourceLock(.*CHILDREN on method-level annotations and remove target = CHILDREN there.

Example fix

// before
@Test
@org.junit.jupiter.api.parallel.ResourceLock(value = "db", target = ResourceLockTarget.CHILDREN)
void myTest() {}
// after
@org.junit.jupiter.api.parallel.ResourceLock(value = "db", target = ResourceLockTarget.CHILDREN)
class MyTest {
    @Test void myTest() {}
}

// Scan test methods for the unsupported annotation shape
for (Method m : testClass.getDeclaredMethods()) {
    ResourceLock rl = m.getAnnotation(ResourceLock.class);
    if (rl != null && rl.target() == ResourceLockTarget.CHILDREN) {
        throw new IllegalStateException("Method " + m + " uses CHILDREN target");
    }
}

When it happens

Trigger: Annotating a @Test, @TestFactory, @RepeatedTest, @ParameterizedTest, or lifecycle method with @ResourceLock(value = "...", target = ResourceLockTarget.CHILDREN).

Common situations: Copy-pasting a class-level @ResourceLock(target = CHILDREN) annotation onto a test method; refactoring a @ClassOrderContext/@ResourceLocks block from the class onto individual methods without changing the target.

Related errors

• Task was deferred but should have been executed synchronousl
• Assumption failed:
• Assumption failed
• This class must not be instantiated
• Implement generateDisplayNameForNestedClass(List<Class<?>>,

AI-assisted analysis of junit-team/junit5@956246301e (2026-08-04). Data as JSON: /data/errors/58a2ed201264e0d6.json. Report an issue: GitHub.