Need code examples on how to use org.junit.platform.launcher.listeners

Question

I run according to the documentation with a test class with 30 tests inside org.junit.platform.launcher.Launcher

I have a function launcher.registerTestExecutionListeners(listener) registered in org.junit.platform.launcher.listeners.TestExecutionSummary

I read the following and don't know how to use it: https://junit.org/junit5/docs/current/user-guide/#running-tests-listeners https://junit.org/junit5/docs/current/api/org.junit.platform.launcher/org/junit/platform/launcher/TestExecutionListener.html

I need listeners: progress - what test is currently running, are there any errors printed, etc.

For example this one:

val listener: SummaryGeneratingListener = SummaryGeneratingListener()
launcher.registerTestExecutionListeners(listener)
val summary: TestExecutionSummary = listener.summary
val failed: Long = summary.testsFailedCount

I need commands: stop/pause/exit/skip, etc.

I need code examples on how to use it. Can anyone help with links?

The next question is asked here: How to terminate the application and make the launcher return to its call by the stop command?

Answer 1

You can create your own custom listener that implements the TestExecutionListener interface and perform custom actions in response to certain events. However, you would need to implement the logic for pausing, exiting, or skipping tests yourself.

This is a simplistic example of how you can create a custom listener:

import org.junit.platform.launcher.TestExecutionListener;
import org.junit.platform.launcher.TestIdentifier;

public class CustomTestExecutionListener implements TestExecutionListener {

  private boolean shouldPause = false;
  private boolean shouldExit = false;
  private boolean shouldSkip = false;

  @Override
  public void executionFinished(TestIdentifier testIdentifier, TestExecutionResult testExecutionResult) {
    System.out.println("Finished test: " + testIdentifier.getDisplayName());
    if (shouldPause) {
      System.out.println("Pausing for 5 seconds");
      try {
        TimeUnit.SECONDS.sleep(5);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
      shouldPause = false;
    }
    if (shouldExit) {
      System.out.println("Exiting test execution");
      System.exit(0);
    }
  }

  public void setShouldPause(boolean shouldPause) {
    this.shouldPause = shouldPause;
  }

  public void setShouldExit(boolean shouldExit) {
    this.shouldExit = shouldExit;
  }

  public void setShouldSkip(boolean shouldSkip) {
    this.shouldSkip = shouldSkip;
  }
}

You can then register the custom listener with the launcher using the registerTestExecutionListeners method:

CustomTestExecutionListener listener = new CustomTestExecutionListener();
launcher.registerTestExecutionListeners(listener);

and set the flags for pausing, exiting, or skipping tests as needed:

listener.setShouldPause(true);
listener.setShouldExit(true);
listener.setShouldSkip(true);