debugging_journey.md

Debugging Journey - Selenium UI Automation Project

This document captures all the major issues, errors, and bugs faced during the development of the ParaBank Selenium UI Automation project, along with their root causes and the exact fixes applied. This serves as a practical debugging reference and a learning log.

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1. ModuleNotFoundError: No module named 'pages'

Where it occurred:

• While running tests from the tests/ directory

Root cause:

• Python could not resolve project-level imports because the project root was not in sys.path.

Fix applied:

• Added project root to Python path in conftest.py.

Final fix snippet:

import sys, os
sys.path.append(os.path.abspath(os.path.dirname(__file__)))

---

2. NameError: name 'LoginPage' is not defined

Where it occurred:

• Inside test_login.py

Root cause:

• LoginPage class was used without importing it.

Fix applied:

• Explicitly imported the page class at the top of the test file.

Final fix:

from pages.login_page import LoginPage

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3. Duplicate Method Definitions Overwriting Each Other

Where it occurred:

• login_page.py

Root cause:

• Same method (get_login_error_message) was defined twice.
• Python silently overwrote the first definition.

Fix applied:

• Removed the duplicate method.
• Kept only the version using WebDriverWait.

---

4. SyntaxError: 'return' outside function

Where it occurred:

• login_page.py

Root cause:

• Incorrect indentation placed return outside method scope.

Fix applied:

• Fixed indentation so return stayed inside the function block.

---

5. TimeoutException While Waiting for Elements

Where it occurred:

• Login success and Accounts Overview checks

Root cause:

• Page was slow to load.
• Element locator was correct but appeared late.

Fix applied:

• Replaced direct find_element calls with WebDriverWait + Expected Conditions.

Example fix:

WebDriverWait(driver, 10).until(
    EC.presence_of_element_located((By.XPATH, "//h1[contains(text(),'Accounts Overview')]"))
)

---

6. Assertion Failing Due to Wrong Error Message

Where it occurred:

• Invalid login test

Root cause:

• Application returned a different message:

  • "An internal error has occurred and has been logged." instead of
  • "could not be verified"

Fix applied:

• Updated assertion to match the actual UI message.

---

7. Tests Passing Individually but Failing Together

Where it occurred:

• When running full pytest suite

Root cause:

• Browser state was shared between tests.

Fix applied:

• Used pytest fixtures to create a fresh browser per test.

---

8. Hardcoded Locators Spread Across Methods

Problem:

• Locators repeated in multiple methods

Fix applied:

• Centralized locators as class-level constants inside Page Objects.

---

9. Flaky Click Actions on Login Button

Root cause:

• Button not clickable immediately

Fix applied:

• Used element_to_be_clickable before clicking.

---

10. Test Structure Becoming Too Verbose

Problem:

• Tests repeated login steps

Fix applied:

• Introduced login_as(username, password) method in LoginPage.

---

11. Pytest Collecting Zero Tests

Root cause:

• Test methods did not start with test_

Fix applied:

• Renamed methods to follow pytest naming conventions.

---

12. Incorrect XPath / CSS Selectors

Root cause:

• Dynamic DOM changes

Fix applied:

• Used resilient locators:

  • contains(text())
  • partial attribute selectors

---

Final Outcome

By systematically debugging each failure and understanding the root cause, this project evolved into:

• A stable Page Object Model framework
• Reliable pytest execution
• Clear separation of tests and UI logic
• Strong real-world debugging experience

This document reflects real automation challenges and their solutions — exactly what recruiters look for.