How to use console launcher --uid option?

[trancexpress]

Hi all,

I'm trying to understand how to use the --uid command line option of the ConsoleLauncher: https://junit.org/junit5/docs/snapshot/user-guide/#running-tests-console-launcher-options-discovering-tests

      --uid, --select-unique-id=UNIQUE-ID...
                             Select a unique id for test discovery. This option can be
                               repeated.

I have two classes:

package test;
abstract class TestBase {
    @org.junit.jupiter.api.Test public void testBase() {}
}

package test;
public class TestSub extends TestBase {
    @org.junit.jupiter.api.Test public void testSub() {}
}

I compile them with:

$ rm test/TestBase.class test/TestSub.class ; /usr/lib/jvm/java-21/bin/javac -cp junit-jupiter-api-5.12.2.jar:junit-jupiter-engine-5.12.2.jar test/TestBase.java test/TestSub.java
warning: unknown enum constant Status.STABLE
  reason: class file for org.apiguardian.api.API$Status not found
1 warning

The structure of the current directory is:

$ tree
.
├── junit-jupiter-api-5.12.2.jar
├── junit-jupiter-engine-5.12.2.jar
├── junit-platform-console-standalone-1.12.2.jar
└── test
    ├── TestBase.class
    ├── TestBase.java
    ├── TestSub.class
    └── TestSub.java

1 directory, 7 files

Then I try to execute one of the test methods via the following commands:

$ /usr/lib/jvm/java-21/bin/java -jar junit-platform-console-standalone-1.12.2.jar execute -cp . --details=verbose -d . -m test.TestSub#testBase

💚 Thanks for using JUnit! Support its development at https://junit.org/sponsoring

Test plan execution started. Number of static tests: 1
╷
├─ JUnit Platform Suite
└─ JUnit Platform Suite finished after 3 ms.
├─ JUnit Jupiter
│  ├─ TestSub
│  │  ├─ testBase()
│  │  │       tags: []
│  │  │   uniqueId: [engine:junit-jupiter]/[class:test.TestSub]/[method:testBase()]
│  │  │     parent: [engine:junit-jupiter]/[class:test.TestSub]
│  │  │     source: MethodSource [className = 'test.TestSub', methodName = 'testBase', methodParameterTypes = '']
│  │  │   duration: 13 ms
│  │  │     status: ✔ SUCCESSFUL
│  └─ TestSub finished after 26 ms.
└─ JUnit Jupiter finished after 48 ms.
├─ JUnit Vintage
└─ JUnit Vintage finished after 1 ms.
Test plan execution finished. Number of all tests: 1

Test run finished after 86 ms
[         4 containers found      ]
[         0 containers skipped    ]
[         4 containers started    ]
[         0 containers aborted    ]
[         4 containers successful ]
[         0 containers failed     ]
[         1 tests found           ]
[         0 tests skipped         ]
[         1 tests started         ]
[         0 tests aborted         ]
[         1 tests successful      ]
[         0 tests failed          ]

This lists the UID of the test as [engine:junit-jupiter]/[class:test.TestSub]/[method:testBase()], which I'm trying to pass via the --uid option:

$ /usr/lib/jvm/java-21/bin/java -jar junit-platform-console-standalone-1.12.2.jar execute -cp . --details=verbose -d . --select-unique-id "[engine:junit-jupiter]/[class:test.TestSub]/[method:testBase()]"

💚 Thanks for using JUnit! Support its development at https://junit.org/sponsoring

Test plan execution started. Number of static tests: 0
╷
├─ JUnit Platform Suite
└─ JUnit Platform Suite finished after 4 ms.
├─ JUnit Jupiter
└─ JUnit Jupiter finished after 4 ms.
├─ JUnit Vintage
└─ JUnit Vintage finished after 1 ms.
Test plan execution finished. Number of all tests: 0

Test run finished after 52 ms
[         3 containers found      ]
[         0 containers skipped    ]
[         3 containers started    ]
[         0 containers aborted    ]
[         3 containers successful ]
[         0 containers failed     ]
[         0 tests found           ]
[         0 tests skipped         ]
[         0 tests started         ]
[         0 tests aborted         ]
[         0 tests successful      ]
[         0 tests failed          ]

This then finds nothing. What am I doing wrong here?

Best regards,
Simeon

---

Background:

I'm looking into an Eclipse JUnit 5 related bug: https://github.com/eclipse-jdt/eclipse.jdt.ui/issues/2235

Eclipse build a request via: LauncherDiscoveryRequestBuilder.request().selectors(DiscoverySelectors.selectUniqueId(UID))

The used UID seems right to me: [engine:junit-jupiter]/[class:test.TestSub]/[method:testBase()]

But the execution fails if the base class (see snippet above) is package private:

org.junit.platform.commons.JUnitException: TestEngine with ID 'junit-jupiter' failed to discover tests
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:165)
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverSafely(EngineDiscoveryOrchestrator.java:132)
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:105)
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:78)
	at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:99)
	at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:77)
	at org.junit.platform.launcher.core.DelegatingLauncher.discover(DelegatingLauncher.java:42)
	at org.junit.platform.launcher.core.InterceptingLauncher.lambda$discover$0(InterceptingLauncher.java:33)
	at org.junit.platform.launcher.core.ClasspathAlignmentCheckingLauncherInterceptor.intercept(ClasspathAlignmentCheckingLauncherInterceptor.java:25)
	at org.junit.platform.launcher.core.InterceptingLauncher.discover(InterceptingLauncher.java:33)
	at org.junit.platform.launcher.core.DelegatingLauncher.discover(DelegatingLauncher.java:42)
	at org.junit.platform.launcher.core.SessionPerRequestLauncher.discover(SessionPerRequestLauncher.java:56)
	at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.<init>(JUnit5TestReference.java:47)
	at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.createUniqueIdTest(JUnit5TestLoader.java:113)
	at org.eclipse.jdt.internal.junit5.runner.JUnit5TestLoader.loadTests(JUnit5TestLoader.java:47)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:504)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:748)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:443)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:211)
Caused by: org.junit.platform.commons.JUnitException: UniqueIdSelector [uniqueId = [engine:junit-jupiter]/[class:test.TestSub]/[method:testBase()]] resolution failed
	at org.junit.platform.launcher.listeners.discovery.AbortOnFailureLauncherDiscoveryListener.selectorProcessed(AbortOnFailureLauncherDiscoveryListener.java:39)
	at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:103)
	at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.run(EngineDiscoveryRequestResolution.java:83)
	at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolver.resolve(EngineDiscoveryRequestResolver.java:116)
	at org.junit.jupiter.engine.discovery.DiscoverySelectorResolver.resolveSelectors(DiscoverySelectorResolver.java:48)
	at org.junit.jupiter.engine.JupiterTestEngine.discover(JupiterTestEngine.java:69)
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:152)
	... 18 more
Caused by: org.junit.platform.commons.JUnitException: UniqueIdSelector [uniqueId = [engine:junit-jupiter]/[class:test.TestSub]/[method:testBase()]] could not be resolved
	at org.junit.platform.launcher.listeners.discovery.AbortOnFailureLauncherDiscoveryListener.selectorProcessed(AbortOnFailureLauncherDiscoveryListener.java:44)
	at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:98)
	... 23 more

I'm trying to figure out if Eclipse is doing something wrong or if this is a JUnit 5 bug. For that I was hoping to run the JUnit 5 ConsoleLauncher, potentially running into the same bug also with just JUnit 5.

[trancexpress]

I was able to move forward with my initial problem, using a snippet similar to the one found here: #3693

I.e. defining a main method and running that.

It would still be nice to know how to use the console launcher for this, but I could progress with my work without this.

[sormuras]

I'm trying to figure out if Eclipse is doing something wrong or if this is a JUnit 5 bug. For that I was hoping to run the JUnit 5 ConsoleLauncher, potentially running into the same bug also with just JUnit 5.

This use-case unearthed two issue: the one about javac vs ecj as described in eclipse-jdt/eclipse.jdt.core#4053, and the one in JUnit regarding the --select-unique-id/--uid option in its console launcher — meanwhile addressed and fixed via

• Fix console launcher --uid option #4587

Thanks for starting this discussion!

[trancexpress]

Thank you for looking into this!

I.e. the invocation should look like this (assuming the jar version has the fix for #4587)?

java -jar junit-platform-console-standalone.jar execute -cp . --select-unique-id "[engine:junit-jupiter]/[class:test.TestSub]/[method:testBase()]"

[sormuras]

Yes.

You can call it already without the patch being released, via the --select "uid:[...]". That generic selector is part of the "explicit selector set". Also assuming you use javac to compile the classes.