Test class consuming page objects in Selenium Java - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of test method using page object

Given the following test class using a page object, what will be the output when the test runs successfully?

Selenium Java

public class LoginPage {
    private WebDriver driver;
    public LoginPage(WebDriver driver) {
        this.driver = driver;
    }
    public void enterUsername(String username) {
        driver.findElement(By.id("username")).sendKeys(username);
    }
    public void enterPassword(String password) {
        driver.findElement(By.id("password")).sendKeys(password);
    }
    public void clickLogin() {
        driver.findElement(By.id("loginBtn")).click();
    }
    public String getWelcomeMessage() {
        return driver.findElement(By.id("welcomeMsg")).getText();
    }
}

public class LoginTest {
    WebDriver driver = new ChromeDriver();
    LoginPage loginPage = new LoginPage(driver);

    @Test
    public void testValidLogin() {
        driver.get("http://example.com/login");
        loginPage.enterUsername("user1");
        loginPage.enterPassword("pass1");
        loginPage.clickLogin();
        String message = loginPage.getWelcomeMessage();
        System.out.println(message);
    }
}

A Prints "Welcome user1!" to the console

B Throws NoSuchElementException at enterUsername

C Prints empty string because welcomeMsg element is missing

D Throws NullPointerException at clickLogin

💡 Hint

Think about what the page object methods do and what the getWelcomeMessage returns after login.

The test simulates a valid login. After clicking login, the page shows a welcome message with the username. The getWelcomeMessage method returns this text, which is printed.

❓ assertion

intermediate

Correct assertion for login success

Which assertion correctly verifies that the login was successful by checking the welcome message using the page object?

Selenium Java

String expectedMessage = "Welcome user1!";
String actualMessage = loginPage.getWelcomeMessage();

A assertNull(actualMessage);

B assertEquals(expectedMessage, actualMessage);

C assertFalse(actualMessage.isEmpty());

D assertTrue(actualMessage.contains("user1"));

💡 Hint

Check which assertion exactly compares the expected and actual welcome messages.

assertEquals compares the expected and actual strings exactly, ensuring the welcome message is correct.

❓ locator

advanced

Best locator for login button in page object

Which locator is the best practice to use for the login button in the page object class to ensure stability and readability?

A By.cssSelector("button.btn-primary")

B By.xpath("//button[text()='Login']")

C By.id("loginBtn")

D By.className("btn")

💡 Hint

Consider uniqueness and stability of locators.

Using By.id is best because IDs are unique and less likely to change, making tests more stable and readable.

🔧 Debug

advanced

Identify cause of NoSuchElementException in test

A test using a page object fails with NoSuchElementException at the line driver.findElement(By.id("password")).sendKeys("pass1");. What is the most likely cause?

A The driver instance is null

B The id "password" is misspelled in the page object

C The sendKeys method is called before driver.get()

D The password input field is not present on the current page

💡 Hint

Think about what causes NoSuchElementException in Selenium.

NoSuchElementException means Selenium cannot find the element. The most common reason is the element is not on the page currently loaded.

❓ framework

expert

Proper test class structure using page objects and JUnit 5

Which test class structure correctly uses JUnit 5 annotations and page objects to initialize WebDriver before all tests and quit after all tests?

A

public class LoginTest {
    static WebDriver driver;
    static LoginPage loginPage;

    @BeforeAll
    public static void setup() {
        driver = new ChromeDriver();
        loginPage = new LoginPage(driver);
    }

    @AfterAll
    public static void teardown() {
        driver.quit();
    }

    @Test
    public void testLogin() {
        driver.get("http://example.com/login");
        loginPage.enterUsername("user1");
        loginPage.enterPassword("pass1");
        loginPage.clickLogin();
        assertEquals("Welcome user1!", loginPage.getWelcomeMessage());
    }
}

B

public class LoginTest {
    WebDriver driver = new ChromeDriver();
    LoginPage loginPage = new LoginPage(driver);

    @BeforeEach
    public void setup() {
        driver = new ChromeDriver();
        loginPage = new LoginPage(driver);
    }

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

    @Test
    public void testLogin() {
        driver.get("http://example.com/login");
        loginPage.enterUsername("user1");
        loginPage.enterPassword("pass1");
        loginPage.clickLogin();
        assertEquals("Welcome user1!", loginPage.getWelcomeMessage());
    }
}

C

public class LoginTest {
    static WebDriver driver;
    LoginPage loginPage;

    @BeforeAll
    public void setup() {
        driver = new ChromeDriver();
        loginPage = new LoginPage(driver);
    }

    @AfterAll
    public void teardown() {
        driver.quit();
    }

    @Test
    public void testLogin() {
        driver.get("http://example.com/login");
        loginPage.enterUsername("user1");
        loginPage.enterPassword("pass1");
        loginPage.clickLogin();
        assertEquals("Welcome user1!", loginPage.getWelcomeMessage());
    }
}

D

public class LoginTest {
    WebDriver driver;
    LoginPage loginPage;

    @BeforeEach
    public void setup() {
        driver = new ChromeDriver();
        loginPage = new LoginPage(driver);
    }

    @AfterAll
    public void teardown() {
        driver.quit();
    }

    @Test
    public void testLogin() {
        driver.get("http://example.com/login");
        loginPage.enterUsername("user1");
        loginPage.enterPassword("pass1");
        loginPage.clickLogin();
        assertEquals("Welcome user1!", loginPage.getWelcomeMessage());
    }
}

💡 Hint

Remember that @BeforeAll and @AfterAll methods must be static in JUnit 5.

Option A correctly uses static methods for @BeforeAll and @AfterAll to initialize and quit WebDriver once for all tests, and initializes the page object accordingly.

Practice

1. What is the main purpose of a test class when it consumes page objects in Selenium Java?

easy

A. To locate web elements directly using Selenium locators

B. To manage browser driver setup and teardown only

C. To define the structure of the web page elements

D. To perform test steps and assertions using methods from page objects

Solution

1. Step 1: Understand roles of test class and page objects

   Page objects encapsulate web element locators and actions. Test classes use these to perform tests.

2. Step 2: Identify test class responsibility

   Test classes call page object methods to execute test steps and verify results with assertions.

3. Final Answer:

   To perform test steps and assertions using methods from page objects -> Option D

4. Quick Check:

   Test class runs tests using page objects [OK]

Hint: Test classes call page object methods to run tests [OK]

Common Mistakes:

• Trying to locate elements directly in test class
• Mixing page object code with test logic
• Using test class only for driver setup

2. Which of the following is the correct way to instantiate a page object in a Selenium Java test class?

easy

A. LoginPage login = new LoginPage(driver);

B. LoginPage login = LoginPage();

C. LoginPage login = new LoginPage();

D. LoginPage login = driver.get(LoginPage.class);

Solution

1. Step 1: Recall page object constructor usage

   Page objects usually require WebDriver passed to constructor for element initialization.

2. Step 2: Check each option for correct syntax

   LoginPage login = new LoginPage(driver); correctly uses 'new' with driver argument. Others miss driver or use invalid syntax.

3. Final Answer:

   LoginPage login = new LoginPage(driver); -> Option A

4. Quick Check:

   Use 'new' with driver parameter [OK]

Hint: Always pass driver to page object constructor [OK]

Common Mistakes:

• Forgetting to pass driver to constructor
• Using constructor without 'new' keyword
• Trying to get page object from driver directly

3. Given the following test class snippet, what will be the output if the login fails?

LoginPage login = new LoginPage(driver);
boolean result = login.login("wrongUser", "wrongPass");
System.out.println(result ? "Login Successful" : "Login Failed");

Assuming login() returns true on success and false on failure.

medium

A. Login Failed

B. Compilation error

C. Login Successful

D. Runtime exception

Solution

1. Step 1: Understand login method behavior

   login() returns true if credentials are correct, false otherwise.

2. Step 2: Analyze given credentials and output

   Credentials are wrong, so login() returns false, printing "Login Failed".

3. Final Answer:

   Login Failed -> Option A

4. Quick Check:

   False login returns "Login Failed" [OK]

Hint: Check boolean return to decide output [OK]

Common Mistakes:

• Assuming login returns exception on failure
• Confusing true/false return values
• Ignoring ternary operator logic

4. Identify the error in this test class code snippet that uses a page object:

public class LoginTest {
  WebDriver driver;
  LoginPage loginPage;

  @Before
  public void setup() {
    driver = new ChromeDriver();
    loginPage = new LoginPage();
  }

  @Test
  public void testLogin() {
    loginPage.login("user", "pass");
  }
}

medium

A. Test method missing assertion

B. WebDriver is not initialized before use

C. LoginPage constructor is called without passing driver

D. Missing @After method to quit driver

Solution

1. Step 1: Check page object instantiation

   LoginPage requires driver in constructor, but called without arguments here.

2. Step 2: Confirm driver initialization

   Driver is initialized correctly before page object creation, so no issue there.

3. Final Answer:

   LoginPage constructor is called without passing driver -> Option C

4. Quick Check:

   Page object needs driver in constructor [OK]

Hint: Always pass driver when creating page objects [OK]

Common Mistakes:

• Forgetting driver parameter in page object constructor
• Assuming driver auto-initializes in page object
• Ignoring missing assertions (not error here)

5. You want to write a test class that uses two page objects: HomePage and ProfilePage. You want to test the flow: login, navigate to profile, update info, and verify success message. Which approach best follows the test class consuming page objects pattern?

hard

A. Write all element locators and actions inside the test class without page objects

B. Instantiate both page objects with driver, call login on HomePage, then call updateProfile on ProfilePage, finally assert success message from ProfilePage

C. Create one page object combining HomePage and ProfilePage methods, then test all steps there

D. Use driver directly in test class to click and send keys for all steps

Solution

1. Step 1: Understand separation of concerns

   Page objects encapsulate page details; test class uses them to perform test steps and assertions.

2. Step 2: Evaluate options for best practice

   Instantiate both page objects with driver, call login on HomePage, then call updateProfile on ProfilePage, finally assert success message from ProfilePage correctly uses separate page objects and test class calls their methods in sequence.

3. Final Answer:

   Instantiate both page objects with driver, call login on HomePage, then call updateProfile on ProfilePage, finally assert success message from ProfilePage -> Option B

4. Quick Check:

   Test class calls page objects methods in flow [OK]

Hint: Use separate page objects, call their methods in test class [OK]

Common Mistakes:

• Putting all locators and actions in test class
• Combining unrelated page objects into one
• Using driver directly instead of page objects