Quarkus - java.lang.RuntimeException: Internal error. The test class SOMECLASS should have been loaded with a QuarkusClassLoader, but instead...

[col-panic]

Running a QuarkusTest class like this

returns

%TESTC  4 v2
%TSTTREE2,ch.elexis.core.tasks.test.TaskServiceTest,true,4,false,1,TaskServiceTest,,[engine:junit-jupiter]/[class:ch.elexis.core.tasks.test.TaskServiceTest]
%TSTTREE3,runnableExecutionContext(ch.elexis.core.tasks.test.TaskServiceTest),false,1,false,2,runnableExecutionContext(),,[engine:junit-jupiter]/[class:ch.elexis.core.tasks.test.TaskServiceTest]/[method:runnableExecutionContext()]
%TSTTREE4,triggerCron(ch.elexis.core.tasks.test.TaskServiceTest),false,1,false,2,triggerCron(),,[engine:junit-jupiter]/[class:ch.elexis.core.tasks.test.TaskServiceTest]/[method:triggerCron()]
%TSTTREE5,reloadOnTaskDescriptorChangeDeleted(ch.elexis.core.tasks.test.TaskServiceTest),false,1,false,2,reloadOnTaskDescriptorChangeDeleted(),,[engine:junit-jupiter]/[class:ch.elexis.core.tasks.test.TaskServiceTest]/[method:reloadOnTaskDescriptorChangeDeleted()]
%TSTTREE6,completedWarnWithManualResolution(ch.elexis.core.tasks.test.TaskServiceTest),false,1,false,2,completedWarnWithManualResolution(),,[engine:junit-jupiter]/[class:ch.elexis.core.tasks.test.TaskServiceTest]/[method:completedWarnWithManualResolution()]
%ERROR  2,ch.elexis.core.tasks.test.TaskServiceTest
%TRACES 
java.lang.RuntimeException: Internal error. The test class class ch.elexis.core.tasks.test.TaskServiceTest should have been loaded with a QuarkusClassLoader, but instead it was loaded with jdk.internal.loader.ClassLoaders$AppClassLoader@2c854dc5. This is caused by the FacadeClassLoader not correctly identifying this class as a QuarkusTest.
        at io.quarkus.test.junit.QuarkusTestExtension.getClassLoaderFromTestClass(QuarkusTestExtension.java:334)
        at io.quarkus.test.junit.QuarkusTestExtension.ensureStarted(QuarkusTestExtension.java:610)
        at io.quarkus.test.junit.QuarkusTestExtension.beforeAll(QuarkusTestExtension.java:687)
        at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)

%TRACEE 

%RUNTIME57

while running a test on the classes test method works (tested clicking on #runnableExecutionContext()) with result

%TESTC  1 v2
%TSTTREE2,ch.elexis.core.tasks.test.TaskServiceTest,true,1,false,1,TaskServiceTest,,[engine:junit-jupiter]/[class:ch.elexis.core.tasks.test.TaskServiceTest]
%TSTTREE3,runnableExecutionContext(ch.elexis.core.tasks.test.TaskServiceTest),false,1,false,2,runnableExecutionContext(),,[engine:junit-jupiter]/[class:ch.elexis.core.tasks.test.TaskServiceTest]/[method:runnableExecutionContext()]
%TESTS  3,runnableExecutionContext(ch.elexis.core.tasks.test.TaskServiceTest)

%TESTE  3,runnableExecutionContext(ch.elexis.core.tasks.test.TaskServiceTest)

%RUNTIME6559

REMARK: This issue was originally posted in redhat-developer/vscode-quarkus#1111

[github-actions]

Hi Marco Descher (@col-panic), I'm an AI Support assistant here to help with your issue. While the team reviews your request, I wanted to provide some possible tips and documentation that might help you in the meantime.

Workaround & Suggestions

• Run the test class through Maven/Surefire instead of the VS Code Test Explorer, which will correctly wire up the QuarkusClassLoader:

  mvn test -Dtest=TaskServiceTest

• In VS Code you can click the ▶️ icon on individual test methods (#runnableExecutionContext(), etc.)—these correctly start under the QuarkusClassLoader.

• Track and subscribe to the upstream issue where class‐level runs aren’t recognized as QuarkusTests:

  • java.lang.RuntimeException: Internal error. The test class SOMECLASS should have been loaded with a QuarkusClassLoader, but instead... redhat-developer/vscode-quarkus#1111

Other references with low confidence

- **Error messages append out of the method when it happens at lifecycle methods** – deals with stack-trace placement, not class-loading for QuarkusTests. https://github.com/microsoft/vscode-java-test/issues/1392 - **When running debug, test dependencies are not included but test codes are.** – about missing test classpath entries under debug, not QuarkusClassLoader. https://github.com//issues/1326

The team will respond to your issue shortly. I hope these suggestions are helpful in the meantime. If this comment helped you, please give it a 👍. If the suggestion was not helpful or incorrect, please give it a 👎. Your feedback helps us improve!

[wenytang-ms]

This isn't a bug in vscode-java-debug/vscode-java-test — it's a class-loading issue in the Eclipse JDT JUnit 5 runtime used to launch JUnit 5 tests (the %TESTC/%TSTTREE output is from JDT's RemoteTestRunner).

Quarkus requires @QuarkusTest classes to be loaded by its QuarkusClassLoader via a FacadeClassLoader installed during discovery. Older JDT loaded the two paths asymmetrically:

• Method run -> selectMethod(clazz.getName()+"#"+name) (string) -> goes through the facade ✅
• Class run -> selectClass(clazz) (already-loaded Class) -> bypasses the facade ❌

Already fixed upstream in Eclipse JDT commit 6e94b0f3 (2025-06-05):

- selectClass(clazz)
+ selectClass(clazz.getName())

Fix: update Language Support for Java(TM) (redhat.java) to a build bundling JDT from June 2025 or later.
Workaround: run individual methods, or mvn test -Dtest=TaskServiceTest.

[wenytang-ms]

Update — this fix is already released, so it should be a matter of updating your extension:

• The JDT fix merged 2025-06-06; eclipse.jdt.ls started bundling it via the 4.37 (2025-09) Eclipse stream from ~2025-06-10.
• It has been shipping in Language Support for Java(TM) (redhat.java) since roughly v1.43/v1.44 (mid-2025) and is present in all current versions (latest v1.50.0).

Please update redhat.java to the latest version (and make sure the Quarkus extension pack pulls the updated redhat.java with it); class-level @QuarkusTest runs should then work.

If you are already on the latest redhat.java and still hit this, that would be a separate regression — please open an issue on https://github.com/redhat-developer/vscode-java with your redhat.java and JDT LS versions.

[wenytang-ms]

close this issue since fixed, please feel free to reopen this issue once you meet again!