Can Selenium take a screenshot on test failure with JUnit?

Question

When my test case fails, especially on our build server, I want to take a picture / screenshot of the screen to help me debug what happened later on. I know how to take a screenshot, but I was hoping for a way in JUnit to call my takeScreenshot() method if a test fails, before the browser is closed.

No, I don't want to go edit our bazillions of tests to add a try/catch. I could maybe, just possibly be talked into an annotation, I suppose. All of my tests have a common parent class, but I can't think of anything I can do there to solve this.

Ideas?

Answer 1

A few quick searches led me to this:

http://blogs.steeplesoft.com/posts/2012/grabbing-screenshots-of-failed-selenium-tests.html

Basically, he recommends creating a JUnit4 Rule that wraps the test Statement in a try/catch block in which he calls:

imageFileOutputStream.write(
    ((TakesScreenshot) driver).getScreenshotAs(OutputType.BYTES));

Does that work for your problem?

Answer 2

If you want to quickly add this behavior to ALL your tests in the run you can use the RunListener interface to listen for test failures.

public class ScreenshotListener extends RunListener {

    private TakesScreenshot screenshotTaker;

    @Override
    public void testFailure(Failure failure) throws Exception {
        File file = screenshotTaker.getScreenshotAs(OutputType.File);
        // do something with your file
    }

}

Add the listener to your test runner like this...

JUnitCore junit = new JUnitCore();
junit.addListener(new ScreenshotListener((TakesScreenShots) webDriver));

// then run your test...

Result result = junit.run(Request.classes(FullTestSuite.class));