Verify login functionality with multiple user credentials

Preconditions (1)

Step 1: Enter username 'user1@example.com' in the username field

Step 2: Enter password 'Password1!' in the password field

Step 3: Click the login button

Step 4: Verify that the user is redirected to the dashboard page

Step 5: Log out and return to the login page

Step 6: Repeat the above steps with username 'user2@example.com' and password 'Password2!'

Step 7: Repeat the above steps with username 'user3@example.com' and password 'Password3!'

✅ Expected Result: Each user is able to log in successfully and is redirected to the dashboard page after login

Automation Requirements - Selenium WebDriver with TestNG

Assertions Needed:

Verify current URL contains '/dashboard' after login

Verify login button is clickable before clicking

Verify logout button is present after login

Best Practices:

Use Page Object Model to separate page interactions

Use explicit waits to wait for elements to be clickable or visible

Separate test data from test logic using data providers

Use assertions to validate expected outcomes clearly

Automated Solution

Selenium Java

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 org.testng.Assert;
import org.testng.annotations.AfterClass;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;
import java.time.Duration;

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

    @BeforeClass
    public void setUp() {
        // Set path to chromedriver executable if needed
        driver = new ChromeDriver();
        wait = new WebDriverWait(driver, Duration.ofSeconds(10));
        driver.manage().window().maximize();
    }

    @DataProvider(name = "loginData")
    public Object[][] loginData() {
        return new Object[][] {
            {"user1@example.com", "Password1!"},
            {"user2@example.com", "Password2!"},
            {"user3@example.com", "Password3!"}
        };
    }

    @Test(dataProvider = "loginData")
    public void testLogin(String username, String password) {
        driver.get("https://example.com/login");

        WebElement usernameField = wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("username")));
        WebElement passwordField = driver.findElement(By.id("password"));
        WebElement loginButton = driver.findElement(By.id("loginBtn"));

        usernameField.clear();
        usernameField.sendKeys(username);
        passwordField.clear();
        passwordField.sendKeys(password);

        wait.until(ExpectedConditions.elementToBeClickable(loginButton));
        loginButton.click();

        // Verify URL contains '/dashboard'
        wait.until(ExpectedConditions.urlContains("/dashboard"));
        Assert.assertTrue(driver.getCurrentUrl().contains("/dashboard"), "User is not on dashboard page after login");

        // Verify logout button is present
        WebElement logoutButton = wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("logoutBtn")));
        Assert.assertTrue(logoutButton.isDisplayed(), "Logout button is not displayed after login");

        // Logout to prepare for next test
        logoutButton.click();

        // Wait until back on login page
        wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("loginBtn")));
    }

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

This test uses Selenium WebDriver with TestNG to automate login tests for multiple users.

Setup: We open a Chrome browser and set an explicit wait to handle dynamic elements.

Data separation: The @DataProvider method loginData holds different username and password pairs. This separates test data from test logic, making it easy to add or change users without modifying the test code.

Test method: The testLogin method runs once for each data set. It navigates to the login page, enters credentials, clicks login, and verifies the user lands on the dashboard page by checking the URL and presence of the logout button.

Assertions: We assert the URL contains '/dashboard' and the logout button is visible to confirm successful login.

Best practices: We use explicit waits to avoid timing issues, clear input fields before typing, and use Page Object Model principles by separating data and actions logically (though a full Page Object class is not shown here for simplicity).

Cleanup: After each login, the test logs out to reset the state for the next user. Finally, the browser closes after all tests.

Common Mistakes - 4 Pitfalls

Hardcoding test data inside the test method

Using Thread.sleep() instead of explicit waits

Not verifying page state after login

Not resetting state between test runs

Bonus Challenge

Now add data-driven testing with 3 different inputs using TestNG DataProvider

Show Hint