How to create a XML report by executing a JAR

Question

I want to develop a stand-alone test-solution delivered as a jar that can be used in a CI/CD environment without being recompiled all the time. Therefore I packed a fat-jar from a multi-maven-module containing a few libaries, a Spring Boot application and a submodule called test-runner.

Executing the fat-jar from within GitLab CI/CD works, but I think that was only the first half of it. I want to produce a JUnit XML report to output the test-results. What I understood from my research is that I would have to implement my own reporter. Is there a more complete example out there?

The test runner

public class Runner {
    SummaryGeneratingListener listener = new SummaryGeneratingListener();

    public void runOne() {
        LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request()
                        .selectors(selectClass(MyTest.class)).build();
        Launcher launcher = LauncherFactory.create();
        TestPlan testPlan = launcher.discover(request);
        launcher.registerTestExecutionListeners(listener);
        launcher.execute(testPlan);
    }

    public static void resultReport(Result result) {
        System.out.println("Finished. Result: Failures: " + result.getFailureCount() + ". Ignored: "
                        + result.getIgnoreCount() + ". Tests run: " + result.getRunCount() + ". Time: "
                        + result.getRunTime() + "ms.");
    }

    public static void main(String[] args) {
        Runner runner = new Runner();
        runner.runOne();
        TestExecutionSummary summary = runner.listener.getSummary();

        summary.printTo(new PrintWriter(System.out));
    }
}

Background: My test-solution is generic and uses a configuration file to parameterize the tests. All tests run in parallel versus a system-under-test. So before this attempt all gitlab-jobs called mvn test to execute the tests and generate the reports, but it recompiled everything every run. I thought about speeding things up.

Answer 1

You can use Console launcher to geneate Junit5 xml reports

java -jar junit-platform-console-standalone-1.6.2.jar @junitArgs.txt --reports-dir=reports

junitArgs.txt file has following info:

-classpath fat jar path
--scan-classpath

Answer 2

To generate XML reports, you can use the LegacyXmlReportGeneratingListener with a path to save your reports to as first argument:

LegacyXmlReportGeneratingListener xmlListener = new LegacyXmlReportGeneratingListener(Paths.get("reports"), new PrintWriter(System.out));

In your runOne() method, you need to register your listener accordingly:

    public void runOne() {
        LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request()
                        .selectors(selectClass(MyTest.class)).build();
        Launcher launcher = LauncherFactory.create();
        TestPlan testPlan = launcher.discover(request);
        launcher.registerTestExecutionListeners(listener);
        launcher.registerTestExecutionListeners(xmlListener);
        launcher.execute(testPlan);
    }

This will generate one XML file per test root in the folder you passed to the listener during initialization. More information can be found in the JavaDoc