Use case testing in Testing Fundamentals - Test Execution Trace

Test Overview

This test simulates a user logging into a website using a valid username and password. It verifies that the login is successful and the user is redirected to the dashboard page.

Test Code - Selenium with unittest

Testing Fundamentals

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
import unittest

class TestLoginUseCase(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.get('https://example.com/login')

    def test_valid_login(self):
        driver = self.driver
        # Find username field and enter username
        username_field = WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.ID, 'username'))
        )
        username_field.send_keys('validUser')

        # Find password field and enter password
        password_field = driver.find_element(By.ID, 'password')
        password_field.send_keys('validPass123')

        # Find and click login button
        login_button = driver.find_element(By.ID, 'loginBtn')
        login_button.click()

        # Wait for dashboard page to load by checking for dashboard element
        dashboard_element = WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.ID, 'dashboard'))
        )

        # Assert dashboard element is displayed
        self.assertTrue(dashboard_element.is_displayed())

    def tearDown(self):
        self.driver.quit()

if __name__ == '__main__':
    unittest.main()

Execution Trace - 7 Steps

Step	Action	System State	Assertion	Result
1	Test starts and browser opens	Browser window opens at 'https://example.com/login' page	—	PASS
2	Waits for username field to be present and enters 'validUser'	Login page shows username input field with id 'username'	Username field is present and ready for input	PASS
3	Finds password field and enters 'validPass123'	Password input field with id 'password' is visible	Password field is present and ready for input	PASS
4	Finds and clicks the login button with id 'loginBtn'	Login button is clickable on the login page	Login button is present and clickable	PASS
5	Waits for dashboard element with id 'dashboard' to appear after login	Browser navigates to dashboard page showing element with id 'dashboard'	Dashboard element is present and displayed	PASS
6	Asserts that dashboard element is displayed	Dashboard page fully loaded and visible	dashboard_element.is_displayed() returns True	PASS
7	Test ends and browser closes	Browser window closes	—	PASS

Failure Scenario

Failing Condition: Dashboard element with id 'dashboard' does not appear within 10 seconds after login

Execution Trace Quiz - 3 Questions

What does the test verify after clicking the login button?

A That the login button changes color

B That the username field is cleared

C That the dashboard page loads and the dashboard element is visible

D That an error message appears

Key Result

Use case testing verifies the entire user journey step-by-step, ensuring each action leads to the expected result, just like following a recipe to bake a cake successfully.

Practice

1. What is the main purpose of use case testing in software testing?

easy

A. To find syntax errors in the source code

B. To verify software behavior by simulating real user actions step-by-step

C. To test only the software's performance under load

D. To check the software's internal code structure

Solution

1. Step 1: Understand use case testing focus

   Use case testing simulates how users interact with software in real scenarios.

2. Step 2: Compare options to definition

   Only To verify software behavior by simulating real user actions step-by-step describes testing by following user actions step-by-step.

3. Final Answer:

   To verify software behavior by simulating real user actions step-by-step -> Option B

4. Quick Check:

   Use case testing = user action simulation [OK]

Hint: Think: Does it test user steps or internal code? [OK]

Common Mistakes:

• Confusing use case testing with code structure testing
• Thinking it tests performance or syntax only
• Ignoring the step-by-step user action focus

2. Which of the following is the correct way to write a use case test step?

easy

A. User logs in with valid username and password.

B. Check if login button is blue.

C. Verify database connection string.

D. Run performance test for login page.

Solution

1. Step 1: Identify use case test step format

   Use case steps describe user actions in simple sentences.

2. Step 2: Match options to format

   User logs in with valid username and password. describes a user action clearly; others focus on UI color, backend, or performance.

3. Final Answer:

   User logs in with valid username and password. -> Option A

4. Quick Check:

   Use case step = user action sentence [OK]

Hint: Look for user action description, not technical checks [OK]

Common Mistakes:

• Choosing UI or backend checks as use case steps
• Confusing performance tests with use case steps
• Writing vague or non-action statements

3. Given this use case test step: User enters invalid password and clicks login, what is the expected result?

medium

A. Application crashes.

B. User is logged in successfully.

C. Error message 'Invalid password' is shown.

D. Password field clears automatically.

Solution

1. Step 1: Analyze the test step

   The user enters an invalid password and tries to log in.

2. Step 2: Determine expected behavior

   The system should reject invalid passwords and show an error message.

3. Final Answer:

   Error message 'Invalid password' is shown. -> Option C

4. Quick Check:

   Invalid input = error message shown [OK]

Hint: Invalid input usually triggers error messages [OK]

Common Mistakes:

• Assuming invalid input logs in user
• Expecting app crash on invalid input
• Thinking fields clear automatically without prompt

4. A use case test step says: User clicks 'Submit' without filling required fields. The test fails because the form submits anyway. What is the likely error?

medium

A. The validation step for required fields is missing or incorrect.

B. The submit button is disabled.

C. The user entered all fields correctly.

D. The form resets after submission.

Solution

1. Step 1: Understand the failure

   The form submits even when required fields are empty, which is wrong.

2. Step 2: Identify cause

   Missing or faulty validation allows submission without required data.

3. Final Answer:

   The validation step for required fields is missing or incorrect. -> Option A

4. Quick Check:

   Missing validation = form submits wrongly [OK]

Hint: Check if validation steps exist for required fields [OK]

Common Mistakes:

• Assuming submit button disables automatically
• Ignoring missing validation logic
• Confusing form reset with submission failure

5. You have a use case testing scenario for an online store checkout:
1. User adds item to cart
2. User proceeds to checkout
3. User enters invalid credit card number
4. User clicks 'Pay'
Which expected result best fits this use case test?

hard

A. Payment is processed successfully.

B. Cart is emptied automatically.

C. User is redirected to homepage without message.

D. Error message 'Invalid credit card number' is displayed and payment is blocked.

Solution

1. Step 1: Review the scenario steps

   User tries to pay with an invalid credit card number.

2. Step 2: Determine correct system response

   The system should block payment and show an error about the invalid card.

3. Final Answer:

   Error message 'Invalid credit card number' is displayed and payment is blocked. -> Option D

4. Quick Check:

   Invalid payment info = error shown, payment blocked [OK]

Hint: Invalid payment info must trigger error and block payment [OK]

Common Mistakes:

• Assuming payment succeeds with invalid data
• Expecting silent redirects without messages
• Thinking cart empties on failed payment