Verify login button functionality with robust selector

Preconditions (1)

Step 1: Locate the login button using a robust CSS selector based on id or unique attribute

Step 2: Click the login button

Step 3: Verify that the login form is submitted or the next page is loaded

✅ Expected Result: Login button is clicked successfully and the login process proceeds without errors

Automation Requirements - Selenium WebDriver with Java

Assertions Needed:

Verify the login button is clickable

Verify the page URL or title changes after clicking login button

Best Practices:

Use By.id or By.cssSelector with stable attributes for locating elements

Avoid using brittle XPath expressions that rely on element position

Use explicit waits to ensure elements are ready before interaction

Organize selectors in a Page Object Model for maintainability

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

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

    @BeforeEach
    public void setUp() {
        driver = new ChromeDriver();
        wait = new WebDriverWait(driver, Duration.ofSeconds(10));
        driver.get("https://example.com/login");
    }

    @Test
    public void testLoginButtonClick() {
        // Use robust selector by id
        By loginButtonSelector = By.id("login-button");

        // Wait until login button is clickable
        WebElement loginButton = wait.until(ExpectedConditions.elementToBeClickable(loginButtonSelector));

        // Click the login button
        loginButton.click();

        // Wait for URL to change or page title to indicate login success
        wait.until(ExpectedConditions.not(ExpectedConditions.urlToBe("https://example.com/login")));

        // Assert URL changed from login page
        String currentUrl = driver.getCurrentUrl();
        assertNotEquals("https://example.com/login", currentUrl, "URL should change after login button click");
    }

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

This test uses Selenium WebDriver with Java to automate clicking the login button on a login page.

We use By.id("login-button") as the selector because IDs are usually unique and stable, making the test less fragile.

We apply an explicit wait with ExpectedConditions.elementToBeClickable to ensure the button is ready before clicking.

After clicking, we wait until the URL changes from the login page URL, indicating the login process proceeded.

Finally, we assert that the URL is different from the login page URL to confirm the click had the expected effect.

Setup and teardown methods initialize and close the browser cleanly.

Common Mistakes - 3 Pitfalls

Using brittle XPath selectors that rely on element position like //div[3]/button

Not using explicit waits before interacting with elements

Hardcoding URLs or page titles without verifying dynamic changes

Bonus Challenge

Now add data-driven testing with 3 different login button selectors to verify robustness

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