Screenshot attachment on failure in Selenium Java - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output when this Selenium test fails?

Consider this Java Selenium test snippet that takes a screenshot on failure. What will be the result if the assertion fails?

Selenium Java

import org.openqa.selenium.*;
import org.openqa.selenium.chrome.ChromeDriver;
import org.testng.Assert;
import org.testng.annotations.*;
import java.io.File;
import org.apache.commons.io.FileUtils;

public class ScreenshotTest {
    WebDriver driver;

    @BeforeMethod
    public void setup() {
        driver = new ChromeDriver();
        driver.get("https://example.com");
    }

    @Test
    public void testTitle() throws Exception {
        try {
            Assert.assertEquals(driver.getTitle(), "Wrong Title");
        } catch (AssertionError e) {
            File src = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
            FileUtils.copyFile(src, new File("failure.png"));
            throw e;
        }
    }

    @AfterMethod
    public void teardown() {
        driver.quit();
    }
}

A Test fails with AssertionError and a screenshot file named 'failure.png' is saved in the project folder.

B Test passes because the screenshot is taken and the error is caught, so no failure is thrown.

C Test fails but no screenshot is saved because FileUtils.copyFile throws IOException that is not handled.

D Test fails and throws a NullPointerException because driver is not initialized.

💡 Hint

Look at how the AssertionError is caught and rethrown after saving the screenshot.

The test asserts the page title against a wrong expected value, so it fails.

The catch block takes a screenshot and saves it as 'failure.png'. Then it rethrows the AssertionError, so the test fails.

No exceptions are thrown from FileUtils.copyFile because it is declared to throw Exception and the test method declares 'throws Exception'.

❓ assertion

intermediate

Which assertion correctly verifies screenshot file creation after failure?

After a Selenium test fails and saves a screenshot named 'error.png', which assertion correctly checks that the screenshot file exists?

Selenium Java

File screenshot = new File("error.png");

A Assert.assertFalse(screenshot.isFile());

B Assert.assertEquals(screenshot.length(), 0);

C Assert.assertTrue(screenshot.exists());

D Assert.assertNull(screenshot);

💡 Hint

Check if the file physically exists on disk.

To verify a file was created, we check if it exists using exists().

Option C correctly asserts the file exists.

Option C checks if file size is zero, which is not guaranteed.

Option C asserts the file is not a file, which is wrong.

Option C asserts the file object is null, which is false.

🔧 Debug

advanced

Why does this screenshot capture code throw IOException?

This Selenium Java code snippet throws IOException during screenshot capture. What is the cause?

Selenium Java

File src = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
FileUtils.copyFile(src, new File("/invalid_path/failure.png"));

A FileUtils.copyFile requires a third argument for overwrite permission.

B The driver is not cast correctly to TakesScreenshot.

C The source file 'src' is null because screenshot failed.

D The destination path '/invalid_path/failure.png' does not exist or is not writable.

💡 Hint

Check the file path permissions and existence.

IOException occurs if the destination path is invalid or not writable.

Option D correctly identifies this cause.

Option D is incorrect because the cast is valid.

Option D is incorrect; getScreenshotAs returns a valid file or throws exception.

Option D is incorrect; copyFile does not require a third argument.

❓ framework

advanced

Which TestNG listener interface is best to implement automatic screenshot on test failure?

You want to automatically capture screenshots on test failures in TestNG without modifying each test method. Which listener interface should you implement?

A ISuiteListener

B ITestListener

C IAnnotationTransformer

D IInvokedMethodListener

💡 Hint

Look for listener that reacts to test method results.

ITestListener provides callbacks like onTestFailure where you can add screenshot logic.

ISuiteListener is for suite-level events, not individual tests.

IAnnotationTransformer is for modifying annotations.

IInvokedMethodListener is for method invocation events but less commonly used for failure handling.

🧠 Conceptual

expert

What is the main benefit of attaching screenshots to test reports on failure?

Why is attaching screenshots to automated test failure reports considered a best practice in software testing?

A It provides visual evidence of the failure, helping faster debugging and communication.

B It reduces the test execution time by skipping logs.

C It automatically fixes UI bugs by capturing screenshots.

D It prevents tests from failing by retrying the failed steps.

💡 Hint

Think about how screenshots help developers and testers understand failures.

Visual evidence from screenshots helps quickly identify what went wrong.

Options A, B, and D are incorrect because screenshots do not affect execution time, fix bugs, or prevent failures.

Practice

1. What is the main purpose of taking a screenshot on test failure in Selenium Java?

easy

A. To automatically fix the test errors

B. To speed up the test execution

C. To visually capture the state of the application at failure

D. To reduce the size of the test report

Solution

1. Step 1: Understand the role of screenshots in testing

   Screenshots help testers see what the application looked like when a test failed.

2. Step 2: Identify the benefit of visual evidence

   This visual evidence helps diagnose issues faster and more clearly than logs alone.

3. Final Answer:

   To visually capture the state of the application at failure -> Option C

4. Quick Check:

   Screenshot = Visual failure evidence [OK]

Hint: Screenshots show what failed visually, not fix or speed tests [OK]

Common Mistakes:

• Thinking screenshots fix errors automatically
• Believing screenshots speed up tests
• Assuming screenshots reduce report size

2. Which Selenium interface is used to capture screenshots in Java?

easy

A. WebDriver

B. JavascriptExecutor

C. Alert

D. TakesScreenshot

Solution

1. Step 1: Recall Selenium interfaces for screenshots

   The TakesScreenshot interface provides the method to capture screenshots.

2. Step 2: Differentiate from other interfaces

   Other interfaces like WebDriver control browser, Alert handles popups, and JavascriptExecutor runs JS scripts.

3. Final Answer:

   TakesScreenshot -> Option D

4. Quick Check:

   TakesScreenshot = Capture screenshots [OK]

Hint: Use TakesScreenshot interface to capture images [OK]

Common Mistakes:

• Using WebDriver directly for screenshots
• Confusing Alert or JavascriptExecutor with screenshot capture
• Not casting driver to TakesScreenshot

3. What will happen if you run this code snippet after a test failure?

File srcFile = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
FileUtils.copyFile(srcFile, new File("screenshots/fail.png"));

medium

A. Compilation error due to missing cast

B. Screenshot saved as fail.png in screenshots folder

C. Runtime error because FileUtils is undefined

D. Screenshot saved but file name is random

Solution

1. Step 1: Analyze the screenshot capture code

   The driver is cast to TakesScreenshot and screenshot saved as a file named "fail.png" in the "screenshots" folder.

2. Step 2: Check for errors or randomness

   FileUtils.copyFile copies the screenshot correctly; file name is fixed as "fail.png" so no randomness.

3. Final Answer:

   Screenshot saved as fail.png in screenshots folder -> Option B

4. Quick Check:

   Code saves fixed-name screenshot file [OK]

Hint: Casting driver and copyFile saves fixed screenshot file [OK]

Common Mistakes:

• Forgetting to cast driver to TakesScreenshot
• Not importing or defining FileUtils
• Expecting random file names without code for it

4. Identify the error in this code snippet for saving a screenshot on failure:

File srcFile = driver.getScreenshotAs(OutputType.FILE);
FileUtils.copyFile(srcFile, new File("screenshots/error.png"));

medium

A. driver must be cast to TakesScreenshot before calling getScreenshotAs

B. FileUtils.copyFile method does not exist

C. OutputType.FILE is invalid for screenshots

D. File path must be absolute, not relative

Solution

1. Step 1: Check method call on driver

   The getScreenshotAs method belongs to TakesScreenshot, so driver must be cast before calling it.

2. Step 2: Verify other parts

   FileUtils.copyFile exists and OutputType.FILE is correct. Relative paths are allowed if folder exists.

3. Final Answer:

   driver must be cast to TakesScreenshot before calling getScreenshotAs -> Option A

4. Quick Check:

   Cast driver to TakesScreenshot before screenshot [OK]

Hint: Always cast driver to TakesScreenshot before getScreenshotAs [OK]

Common Mistakes:

• Calling getScreenshotAs directly on WebDriver
• Assuming OutputType.FILE is wrong
• Thinking relative paths cause errors

5. You want to attach a screenshot to your test report only when a test fails. Which approach correctly implements this in Selenium Java with TestNG?

@AfterMethod
public void tearDown(ITestResult result) {
  if (result.getStatus() == ITestResult.FAILURE) {
    File src = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
    File dest = new File("screenshots/" + result.getName() + ".png");
    FileUtils.copyFile(src, dest);
    // Attach dest to report here
  }
  driver.quit();
}

hard

A. This code saves screenshot only on failure and attaches it correctly

B. Screenshot is saved on every test, not just failures

C. FileUtils.copyFile will throw error without try-catch

D. result.getName() returns null, so file name is invalid

Solution

1. Step 1: Check condition for failure

   The code checks if test status is FAILURE before taking screenshot, so it runs only on failures.

2. Step 2: Verify screenshot saving and naming

   Screenshot saved with test method name, which is valid. Attaching to report is indicated as a comment.

3. Step 3: Confirm no errors in logic

   FileUtils.copyFile may throw IOException but typically handled or declared; this snippet focuses on logic correctness.

4. Final Answer:

   This code saves screenshot only on failure and attaches it correctly -> Option A

5. Quick Check:

   Screenshot on failure only with correct naming [OK]

Hint: Use ITestResult.FAILURE check to save screenshots only on failure [OK]

Common Mistakes:

• Taking screenshots regardless of test result
• Not handling exceptions from file operations
• Assuming getName() returns null