How can I verify Error Message on a webpage using Selenium Webdriver?

Selenium WebDriver is an essential tool for automating web application testing, allowing testers to ensure that applications function correctly and efficiently. One critical aspect of this testing is verifying error messages, which are crucial for user feedback, especially when invalid inputs are provided or issues arise.

In this guide, we'll explore how to verify an error message using Selenium WebDriver by focusing on a practical example with the GeeksforGeeks (GFG) login page. This demonstration will help you understand the process of checking for error messages to ensure your web application's error-handling mechanisms work as expected.

Steps to Verify the Error Message

Suppose we are testing the login functionality of the GFG website. If a user enters invalid credentials (e.g., incorrect email or password), an error message should be displayed. Our goal is to verify that this error message appears as expected.

1. Set up Selenium WebDriver: Ensure that you have installed the necessary dependencies, including the Selenium package and WebDriver for your browser (e.g., Chrome Driver).
2. Locate the necessary elements: Use Selenium to locate the input fields for the username and password, as well as the element that displays the error message.
3. Submit invalid credentials: Enter incorrect login details and submit the form to trigger the error message.
4. Capture and verify the error message: Retrieve the text of the error message displayed on the webpage and compare it with the expected message.

Example

Below is the Python code that demonstrates the steps mentioned above to verify the error message on the GeeksforGeeks login page using Selenium WebDriver.

package com.example.tests;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import io.github.bonigarcia.wdm.WebDriverManager;

public class VerifyErrorMessage {
    public static void main(String[] args) {
        // Set up ChromeDriver using WebDriverManager
        WebDriverManager.chromedriver().setup();

        // Initialize ChromeDriver instance
        WebDriver driver = new ChromeDriver();

        // Maximize the browser window
        driver.manage().window().maximize();

        try {
            // Navigate to the GFG login page
            driver.get("https://auth.geeksforgeeks.org/");

            // Locate the username and password fields
            WebElement usernameField = driver.findElement(By.id("luser"));
            WebElement passwordField = driver.findElement(By.id("password"));

            // Enter invalid credentials
            usernameField.sendKeys("invalid_username");
            passwordField.sendKeys("invalid_password");
            passwordField.submit();

            // Introduce a small delay to allow the error message to load
            Thread.sleep(3000);

            // Capture the error message
            WebElement errorMessage = driver.findElement(By.cssSelector(".alert.alert-danger"));
            String actualMessage = errorMessage.getText();

            // Verify the error message
            String expectedMessage = "Invalid email or password.";
            if (actualMessage.equals(expectedMessage)) {
                System.out.println("Test Passed: Error message verified successfully.");
            } else {
                System.out.println("Test Failed: Expected message '" + expectedMessage + "', but got '" + actualMessage + "'.");
            }
        } catch (Exception e) {
            System.out.println("An error occurred: " + e.getMessage());
            e.printStackTrace();
        } finally {
            // Close the WebDriver
            driver.quit();
        }
    }
}

Explanation of the Code

1. We start by initializing the WebDriver for Chrome (you can use other browsers like Firefox or Edge by downloading the respective WebDriver).
2. The get() method is used to navigate to the GFG login page.
3. Using Selenium's find_element() method, we locate the username and password input fields by their HTML IDs (luser and password respectively).
4. Invalid credentials are entered into the form, and the RETURN key is pressed to submit it.
5. A small delay (3 seconds) is introduced to allow the page to load the error message after submission.
6. The error message is captured using the css Selector associated with it (.alert.alert-dange).
7. The captured error message is compared with the expected error message using an assert statement. If the messages match, the test passes; otherwise, an assertion error is raised.
8. Finally, the WebDriver is closed to end the session.

Output

If the test runs successfully, the error message will be verified without any issues. If the assertion fails, an error message will be displayed indicating the mismatch between the expected and actual error messages.

Conclusion

In this article, we've learned how to use Selenium WebDriver to verify error messages on the GeeksforGeeks (GFG) login page. By automating the process of entering invalid credentials and capturing the resulting error message, we ensure that the application provides accurate and appropriate feedback to users. This approach is vital for maintaining a smooth user experience and robust error handling.

With Selenium WebDriver, you can effectively test and validate error messages across various web applications, enhancing the reliability and usability of your software.