Listeners for Screenshots on Failure

A TestNG listener is a class whose methods TestNG calls on events: test start, success, failure, skip. The most common use: take a screenshot whenever a test fails, without writing try/catch in every test.

public class TestListener implements ITestListener {
    private static final Logger log = LogManager.getLogger(TestListener.class);

    @Override
    public void onTestStart(ITestResult result) {
        log.info("STARTED {}", result.getName());
    }

    @Override
    public void onTestFailure(ITestResult result) {
        WebDriver driver = DriverFactory.getDriver();
        if (driver == null) return;
        File src = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
        Path target = Path.of("target", "screenshots", result.getName() + ".png");
        try {
            Files.createDirectories(target.getParent());
            Files.copy(src.toPath(), target, StandardCopyOption.REPLACE_EXISTING);
            log.error("FAILED {} - screenshot {}", result.getName(), target);
        } catch (IOException e) {
            log.warn("Could not save screenshot", e);
        }
    }
}