Screenshot attachment on failure in Selenium Java - Build an Automation Script

Capture screenshot when test fails

Preconditions (3)

Step 1: Open the browser and navigate to 'https://example.com/login'

Step 2: Enter 'wronguser' in the username field

Step 3: Enter 'wrongpass' in the password field

Step 4: Click the login button

Step 5: Verify that the login failed by checking the error message is displayed

Step 6: If the verification fails, capture a screenshot and save it to 'screenshots' folder

✅ Expected Result: On test failure, a screenshot image file is saved with a timestamped filename in the 'screenshots' folder

Automation Requirements - TestNG with Selenium WebDriver

Assertions Needed:

Assert that the error message element is displayed after login attempt

Best Practices:

Use @AfterMethod to capture screenshot on failure

Use explicit waits to wait for elements

Use descriptive file names with timestamps for screenshots

Use Page Object Model for element locators (optional but recommended)

Automated Solution

Selenium Java

import org.openqa.selenium.By;
import org.openqa.selenium.OutputType;
import org.openqa.selenium.TakesScreenshot;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.support.ui.WebDriverWait;
import org.testng.Assert;
import org.testng.ITestResult;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import java.time.Duration;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class LoginTest {
    private WebDriver driver;
    private WebDriverWait wait;

    @BeforeMethod
    public void setUp() {
        driver = new ChromeDriver();
        wait = new WebDriverWait(driver, Duration.ofSeconds(10));
        driver.manage().window().maximize();
    }

    @Test
    public void testInvalidLoginShowsError() {
        driver.get("https://example.com/login");

        WebElement usernameInput = wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("username")));
        usernameInput.sendKeys("wronguser");

        WebElement passwordInput = driver.findElement(By.id("password"));
        passwordInput.sendKeys("wrongpass");

        WebElement loginButton = driver.findElement(By.id("loginBtn"));
        loginButton.click();

        WebElement errorMsg = wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("error-message")));
        Assert.assertTrue(errorMsg.isDisplayed(), "Error message should be displayed on invalid login");
    }

    @AfterMethod
    public void tearDown(ITestResult result) {
        if (ITestResult.FAILURE == result.getStatus()) {
            takeScreenshot(result.getName());
        }
        if (driver != null) {
            driver.quit();
        }
    }

    private void takeScreenshot(String testName) {
        try {
            File srcFile = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
            String timestamp = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyyMMdd_HHmmss"));
            Path destPath = Path.of("screenshots", testName + "_" + timestamp + ".png");
            Files.createDirectories(destPath.getParent());
            Files.copy(srcFile.toPath(), destPath, StandardCopyOption.REPLACE_EXISTING);
            System.out.println("Screenshot saved to: " + destPath.toAbsolutePath());
        } catch (IOException e) {
            System.err.println("Failed to save screenshot: " + e.getMessage());
        }
    }
}

This test class uses Selenium WebDriver with TestNG to automate a login failure scenario.

setUp() initializes the Chrome browser and sets an explicit wait.

testInvalidLoginShowsError() opens the login page, enters wrong credentials, clicks login, and asserts the error message is visible.

tearDown() runs after each test. If the test failed, it calls takeScreenshot() to capture the browser screen and save it with a timestamped filename in the screenshots folder. Then it closes the browser.

takeScreenshot() uses Selenium's TakesScreenshot interface to get the screenshot file, creates the folder if needed, and saves the file with a name that includes the test method name and current time. This helps identify which test failed and when.

This approach ensures that any failure during the test run is documented visually, helping debugging.

Common Mistakes - 4 Pitfalls

Not using explicit waits before interacting with elements

Taking screenshot only inside the test method

Hardcoding screenshot file paths without creating directories

Using fixed screenshot file names

Bonus Challenge

Now add data-driven testing with 3 different invalid username and password combinations

Show Hint