Automate login functionality using Page Object pattern

Preconditions (2)

Step 1: Open the login page URL

Step 2: Enter 'user@example.com' in the email input field

Step 3: Enter 'Password123' in the password input field

Step 4: Click the login button

Step 5: Verify that the user is redirected to the dashboard page with URL containing '/dashboard'

✅ Expected Result: User successfully logs in and dashboard page is displayed

Automation Requirements - JUnit 5 with Selenium WebDriver

Assertions Needed:

Verify current URL contains '/dashboard' after login

Verify login button is clickable before clicking

Best Practices:

Use Page Object Model to separate page structure from test logic

Use explicit waits to wait for elements to be ready

Use meaningful assertions with clear messages

Automated Solution

JUnit

import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.openqa.selenium.By;
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 static org.junit.jupiter.api.Assertions.*;
import java.time.Duration;

// Page Object for Login Page
class LoginPage {
    private WebDriver driver;
    private WebDriverWait wait;

    private By emailField = By.id("email");
    private By passwordField = By.id("password");
    private By loginButton = By.id("loginBtn");

    public LoginPage(WebDriver driver) {
        this.driver = driver;
        this.wait = new WebDriverWait(driver, Duration.ofSeconds(10));
    }

    public void open() {
        driver.get("http://example.com/login");
    }

    public void enterEmail(String email) {
        WebElement emailInput = wait.until(ExpectedConditions.visibilityOfElementLocated(emailField));
        emailInput.clear();
        emailInput.sendKeys(email);
    }

    public void enterPassword(String password) {
        WebElement passwordInput = wait.until(ExpectedConditions.visibilityOfElementLocated(passwordField));
        passwordInput.clear();
        passwordInput.sendKeys(password);
    }

    public void clickLogin() {
        WebElement loginBtn = wait.until(ExpectedConditions.elementToBeClickable(loginButton));
        loginBtn.click();
    }
}

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

    @BeforeEach
    public void setUp() {
        driver = new ChromeDriver();
        wait = new WebDriverWait(driver, Duration.ofSeconds(10));
        loginPage = new LoginPage(driver);
    }

    @Test
    public void testSuccessfulLogin() {
        loginPage.open();
        loginPage.enterEmail("user@example.com");
        loginPage.enterPassword("Password123");
        loginPage.clickLogin();

        // Wait for URL to contain /dashboard
        boolean urlContainsDashboard = wait.until(ExpectedConditions.urlContains("/dashboard"));
        assertTrue(urlContainsDashboard, "URL should contain '/dashboard' after login");
    }

    @AfterEach
    public void tearDown() {
        if (driver != null) {
            driver.quit();
        }
    }
}

This test uses the Page Object Model pattern to separate the login page details from the test logic. The LoginPage class contains methods to interact with the login page elements. This makes the test easier to read and maintain.

Explicit waits ensure elements are ready before interacting, avoiding flaky tests. Assertions check that after login, the URL contains '/dashboard', confirming successful login.

The setup and teardown methods initialize and close the browser cleanly for each test run.

Common Mistakes - 3 Pitfalls

Hardcoding element locators directly in the test method

Using Thread.sleep() instead of explicit waits

Not verifying element is clickable before clicking

Bonus Challenge

Now add data-driven testing with 3 different sets of login credentials (valid and invalid)

Show Hint