Page class design in Selenium Java - Test Execution Trace

Test Overview

This test verifies that the Page class correctly locates and interacts with the login button on a web page. It checks that clicking the button triggers the expected behavior.

Test Code - JUnit 5 with Selenium WebDriver

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

class LoginPage {
    private WebDriver driver;
    private By loginButtonLocator = By.id("login-btn");

    public LoginPage(WebDriver driver) {
        this.driver = driver;
    }

    public WebElement getLoginButton() {
        return driver.findElement(loginButtonLocator);
    }

    public void clickLogin() {
        getLoginButton().click();
    }
}

public class LoginPageTest {
    private WebDriver driver;
    private LoginPage loginPage;

    @BeforeEach
    public void setUp() {
        driver = new ChromeDriver();
        driver.get("https://example.com/login");
        loginPage = new LoginPage(driver);
    }

    @Test
    public void testClickLoginButton() {
        loginPage.clickLogin();
        String currentUrl = driver.getCurrentUrl();
        assertTrue(currentUrl.contains("dashboard"), "URL should contain 'dashboard' after login click");
    }

    @AfterEach
    public void tearDown() {
        driver.quit();
    }
}

Execution Trace - 8 Steps

Step	Action	System State	Assertion	Result
1	Test starts	JUnit test runner initialized	—	PASS
2	Browser opens ChromeDriver	Chrome browser window opens	—	PASS
3	Navigates to https://example.com/login	Login page is loaded in browser	Page URL is https://example.com/login	PASS
4	LoginPage object is created with driver	Page class ready to interact with elements	—	PASS
5	Finds login button by id 'login-btn'	Login button element is located on page	Element is present and visible	PASS
6	Clicks login button	Browser processes click event	—	PASS
7	Checks current URL contains 'dashboard'	Browser URL updated after click	assertTrue(currentUrl.contains("dashboard"))	PASS
8	Test ends and browser closes	Browser window closed, resources freed	—	PASS

Failure Scenario

Failing Condition: Login button with id 'login-btn' is not found on the page

Execution Trace Quiz - 3 Questions

What does the test verify after clicking the login button?

A The URL contains 'dashboard'

B The login button disappears

C The page title changes to 'Login'

D An alert popup appears

Key Result

Designing a Page class with clear element locators and interaction methods helps keep tests clean and easy to maintain.

Practice

1. What is the main purpose of a page class in Selenium Java?

easy

A. To handle API requests

B. To write test assertions directly

C. To group web page elements and actions in one place

D. To manage database connections

Solution

1. Step 1: Understand the role of page classes

   Page classes organize locators and actions related to a specific web page.

2. Step 2: Identify the main purpose

   This organization improves code readability and reuse by keeping page details in one place.

3. Final Answer:

   To group web page elements and actions in one place -> Option C

4. Quick Check:

   Page class purpose = Group elements and actions [OK]

Hint: Page classes group elements and actions per page [OK]

Common Mistakes:

• Confusing page classes with test classes
• Using page classes for database or API logic
• Writing assertions inside page classes

2. Which of the following is the correct way to declare a locator in a Selenium page class using Java?

easy

A. public void submitButton = driver.findElement(By.id("submit"));

B. public String submitButton = "submit";

C. private WebElement submitButton = driver.findElement(By.id("submit"));

D. private By submitButton = By.id("submit");

Solution

1. Step 1: Recall best practice for locators

   Locators should be stored as By objects, not WebElement, to delay element lookup.

2. Step 2: Check each option

   private By submitButton = By.id("submit"); correctly declares a private By locator with By.id("submit").

3. Final Answer:

   private By submitButton = By.id("submit"); -> Option D

4. Quick Check:

   Locators = By objects [OK]

Hint: Use By for locators, not WebElement directly [OK]

Common Mistakes:

• Declaring locators as WebElement fields
• Using public visibility for locators
• Assigning void type to variables

3. Given the following page class snippet, what will loginPage.getTitle() return if the page title is "Welcome Page"?

public class LoginPage {
  private WebDriver driver;
  public LoginPage(WebDriver driver) {
    this.driver = driver;
  }
  public String getTitle() {
    return driver.getTitle();
  }
}

medium

A. "Welcome Page"

B. "Login Page"

C. null

D. Throws NullPointerException

Solution

1. Step 1: Understand getTitle() method

   The method calls driver.getTitle(), which returns the current page title.

2. Step 2: Match with given page title

   The page title is "Welcome Page", so getTitle() returns this string.

3. Final Answer:

   "Welcome Page" -> Option A

4. Quick Check:

   driver.getTitle() = "Welcome Page" [OK]

Hint: driver.getTitle() returns current page title string [OK]

Common Mistakes:

• Assuming getTitle() returns page class name
• Expecting null if not set explicitly
• Confusing with element text retrieval

4. Identify the error in this page class method:

public void clickLogin() {
  WebElement loginBtn = driver.findElement(By.id("login"));
  loginBtn.click();
}

medium

A. No error, method is correct

B. Should store locator as a By field, not find element inside method

C. Missing exception handling for element not found

D. Method should return WebElement instead of void

Solution

1. Step 1: Review locator usage best practice

   Locators should be stored as By fields in the page class, not found inside methods.

2. Step 2: Identify the problem

   Finding element inside method reduces reuse and violates page class design principles.

3. Final Answer:

   Should store locator as a By field, not find element inside method -> Option B

4. Quick Check:

   Locators as By fields = best practice [OK]

Hint: Keep locators as fields, find elements in methods [OK]

Common Mistakes:

• Finding elements repeatedly inside methods
• Ignoring locator reuse
• Assuming exception handling is mandatory here

5. You want to design a page class for a login page with username, password fields, and a login button. Which design approach is best to follow?

hard

A. Store locators as private By fields; create public methods to enter username, enter password, and click login

B. Store WebElement fields publicly and access them directly in tests

C. Write all test steps inside the page class constructor

D. Use static methods only without storing any locators

Solution

1. Step 1: Recall page class design principles

   Locators should be private By fields; actions should be public methods for reuse and encapsulation.

2. Step 2: Evaluate options

   Store locators as private By fields; create public methods to enter username, enter password, and click login follows best practice by separating locators and actions clearly.

3. Final Answer:

   Store locators as private By fields; create public methods to enter username, enter password, and click login -> Option A

4. Quick Check:

   Private locators + public methods = best design [OK]

Hint: Private locators + public action methods = good page class [OK]

Common Mistakes:

• Making locators public and exposing WebElements
• Putting test logic in constructors
• Using static methods without instance context