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 s

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));

Answer 3

If you want to take a screenshot on test failure, add this class

import java.io.File;

import java.io.IOException;

import java.util.UUID;

import org.apache.commons.io.FileUtils;

import org.junit.rules.MethodRule;

import org.junit.runners.model.FrameworkMethod;

import org.junit.runners.model.Statement;

import org.openqa.selenium.OutputType;

import org.openqa.selenium.TakesScreenshot;

import org.openqa.selenium.WebDriver;

public class ScreenShotOnFailure implements MethodRule {

    private WebDriver driver;

    public ScreenShotOnFailure(WebDriver driver){
        this.driver = driver;
    }

    public Statement apply(final Statement statement, final FrameworkMethod frameworkMethod, final Object o) {
        return new Statement() {
            @Override
            public void evaluate() throws Throwable {
                try {
                    statement.evaluate();
                } catch (Throwable t) {
                    captureScreenShot(frameworkMethod.getName());
                    throw t;
                }
            }

            public void captureScreenShot(String fileName) throws IOException {
                File scrFile = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
                fileName += UUID.randomUUID().toString();
                File targetFile = new File("./Screenshots/" + fileName + ".png");
                FileUtils.copyFile(scrFile, targetFile);
            }
        };
    }
}

And Before all tests, you should use this Rule:

@Rule
public ScreenShotOnFailure failure = new ScreenShotOnFailure(driver));

@Before
public void before() {
   ...
}