How to Capture Screenshots on Test Failures, attach to Reports

UI Test Automation Framewok Interview Question Series

When automated UI tests fail, a screenshot can provide invaluable context for troubleshooting. Instead of relying solely on stack traces or log files, a captured image shows the exact state of the application at the moment of failure, making it much easier to identify the root cause. Here we answer the beloved interview question: “How to Capture Screenshots on Test Failures, attach to Reports?

In Selenium WebDriver with Java, you can automate screenshot capture using the TakesScreenshot interface and integrate it with a TestNG Listener. This approach ensures that every failed test automatically generates a screenshot and attaches it to your test report, such as Extent Reports, Allure Reports

Create a Screenshot Utility

The first step is to create a reusable utility method that captures a screenshot and returns the file path.

public class ScreenshotUtil {
    public static String captureScreenshot(WebDriver driver, String testName) {
        TakesScreenshot ts = (TakesScreenshot) driver;
        File src = ts.getScreenshotAs(OutputType.FILE);
        String path = "./Screenshots/" + testName + "_" +
                      System.currentTimeMillis() + ".png";
        FileHandler.copy(src, new File(path));
        return path;
    }
}

This utility:

• Uses Selenium’s TakesScreenshot interface.
• Saves the image with a unique timestamp.
• Returns the screenshot path for reporting purposes.

Capture Screenshots Using a TestNG Listener

Rather than adding screenshot logic to every test case, implement the ITestListener interface and use the onTestFailure() callback.

public class ListenerTest implements ITestListener {
    @Override
    public void onTestFailure(ITestResult result) {
        WebDriver driver = DriverManager.getDriver();
        String screenshotPath = ScreenshotUtil.captureScreenshot(driver, result.getName());
        // Attach screenshot to Extent Reports
        ExtentReportTestsTracker.logFail("Test Failed");
        ExtentReportTestsTracker.getCurrentTest()
                .addScreenCaptureFromPath(screenshotPath);
    }
}

Whenever a test fails, the listener automatically:

• Retrieves the current WebDriver instance.
• Captures a screenshot.
• Saves it to the designated folder.
• Attaches it to the Extent Report.

Best Practices

To get the most from your screenshot implementation:

• Capture screenshots only when a test fails to avoid unnecessary storage usage.
• Include timestamps in filenames to prevent overwriting previous screenshots.
• Store screenshots in a dedicated directory within your project or CI workspace.
• Integrate screenshots with reporting frameworks like Extent Reports or Allure Reports.
• Consider uploading screenshots as CI artifacts for easy access after pipeline execution.

Final Thoughts

Capturing screenshots on test failures is a simple enhancement that significantly improves the effectiveness of Selenium test automation. By combining a reusable screenshot utility with a TestNG listener, you can automatically collect visual evidence for every failed test and include it directly in your reports.

Related Articles

TestNG Guide Page

Selenium Framework Design

Interview Preparation Page

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