Conftest for shared fixtures in Selenium Python - Framework Patterns

Framework Mode - Conftest for shared fixtures

Folder Structure

selenium-python-project/
├── tests/
│   ├── test_login.py
│   ├── test_checkout.py
│   └── test_profile.py
├── pages/
│   ├── login_page.py
│   ├── checkout_page.py
│   └── profile_page.py
├── utils/
│   └── helpers.py
├── conftest.py
└── pytest.ini
  

Test Framework Layers

• Driver Layer: Managed by fixtures in conftest.py to create and close Selenium WebDriver instances.
• Page Objects: Classes in pages/ folder representing UI pages with methods for user actions.
• Test Cases: Test scripts in tests/ folder using pytest and shared fixtures.
• Utilities: Helper functions in utils/ for reusable code like waits or data generation.
• Configuration: pytest.ini for pytest settings and conftest.py for shared fixtures and hooks.

Configuration Patterns

Use conftest.py to define shared fixtures that provide WebDriver setup and teardown. Example patterns:

• Browser choice: Use pytest command line options to select browser (e.g., Chrome, Firefox).
• Environment variables: Store URLs and credentials in environment variables or config files, accessed in fixtures.
• Fixture scope: Use scope="function" for fresh browser per test or scope="session" for reuse.

Example snippet in conftest.py:

import pytest
from selenium import webdriver

@pytest.fixture(scope="function")
def driver(request):
    browser = request.config.getoption("browser") or "chrome"
    if browser == "chrome":
        driver = webdriver.Chrome()
    elif browser == "firefox":
        driver = webdriver.Firefox()
    else:
        raise ValueError(f"Unsupported browser: {browser}")
    driver.maximize_window()
    yield driver
    driver.quit()

# Add pytest_addoption to accept --browser CLI argument

def pytest_addoption(parser):
    parser.addoption(
        "--browser",
        action="store",
        default="chrome",
        help="Browser to run tests on: chrome or firefox"
    )
  

Test Reporting and CI/CD Integration

• Use pytest built-in reporting with pytest --junitxml=report.xml to generate XML reports.
• Integrate with CI tools like Jenkins, GitHub Actions, or GitLab CI to run tests on push or pull requests.
• Use plugins like pytest-html for readable HTML reports.
• Configure CI to install dependencies, run tests with selected browser, and archive reports.

Best Practices

• Centralize fixtures: Put shared fixtures in conftest.py to avoid duplication and ease maintenance.
• Use fixture scopes wisely: Choose function scope for isolation or session for speed depending on test needs.
• Parameterize fixtures: Allow browser or environment selection via command line options for flexibility.
• Clean up resources: Always quit WebDriver in fixture teardown to avoid leftover browser processes.
• Keep tests independent: Use fresh fixtures or reset state to avoid flaky tests.

Self Check

Where in this framework structure would you add a new fixture to provide a logged-in user session for tests?

Key Result

Use conftest.py to define shared, reusable fixtures for WebDriver setup and test environment configuration.

Practice

1. What is the main purpose of a conftest.py file in Selenium Python testing?

easy

A. To hold shared fixtures for setup and cleanup across multiple test files

B. To store test data in JSON format

C. To define Selenium WebDriver locators

D. To write test cases directly

Solution

1. Step 1: Understand the role of conftest.py

   The conftest.py file is used to define fixtures that can be shared across multiple test files for setup and cleanup tasks.

2. Step 2: Differentiate from other files

   It does not store test data, locators, or test cases directly but provides reusable setup code like browser initialization.

3. Final Answer:

   To hold shared fixtures for setup and cleanup across multiple test files -> Option A

4. Quick Check:

   conftest.py = shared fixtures [OK]

Hint: Remember: conftest.py shares setup code across tests [OK]

Common Mistakes:

• Confusing conftest.py with test case files
• Thinking conftest.py stores test data
• Using conftest.py to write test assertions

2. Which of the following is the correct way to declare a fixture in conftest.py using pytest?

easy

A. def browser(): yield webdriver.Chrome()

B. @pytest.fixture
def browser(): yield webdriver.Chrome()

C. fixture browser(): yield webdriver.Chrome()

D. @fixture def browser(): return webdriver.Chrome()

Solution

1. Step 1: Identify correct fixture decorator usage

   pytest fixtures require the @pytest.fixture decorator above the function to mark it as a fixture.

2. Step 2: Check syntax correctness

   @pytest.fixture def browser(): yield webdriver.Chrome() correctly uses @pytest.fixture and a generator with yield to provide the resource.

3. Final Answer:

   @pytest.fixture\ndef browser(): yield webdriver.Chrome() -> Option B

4. Quick Check:

   Use @pytest.fixture decorator [OK]

Hint: Always prefix fixture functions with @pytest.fixture [OK]

Common Mistakes:

• Omitting @pytest.fixture decorator
• Using wrong decorator name like @fixture
• Not using yield for setup/teardown

3. Given this fixture in conftest.py:

@pytest.fixture
def browser():
    driver = webdriver.Chrome()
    yield driver
    driver.quit()

What happens when a test uses this fixture?

medium

A. The browser never opens because yield is missing

B. The browser opens and closes immediately before the test runs

C. The browser opens but never closes

D. The browser opens before the test and closes after the test finishes

Solution

1. Step 1: Understand yield in fixture

   The yield statement pauses the fixture, providing the driver to the test, then resumes after the test to run cleanup.

2. Step 2: Analyze setup and teardown

   Driver is created before yield (browser opens), and driver.quit() runs after test finishes (browser closes).

3. Final Answer:

   The browser opens before the test and closes after the test finishes -> Option D

4. Quick Check:

   yield = setup before, cleanup after [OK]

Hint: yield splits setup and teardown in fixtures [OK]

Common Mistakes:

• Thinking yield closes browser immediately
• Forgetting driver.quit() after yield
• Assuming browser stays open forever

4. You wrote this fixture in conftest.py:

@pytest.fixture
def browser():
    driver = webdriver.Chrome()
    return driver
    driver.quit()

What is the problem with this fixture?

medium

A. driver.quit() is never called, so browser stays open after tests

B. Syntax error because return and yield cannot be used together

C. Fixture will not provide the driver to tests

D. driver.quit() runs before driver is created

Solution

1. Step 1: Analyze return and driver.quit() placement

   Since return exits the function immediately, driver.quit() after it never runs.

2. Step 2: Understand impact on browser lifecycle

   Without driver.quit(), the browser stays open after tests, causing resource leaks.

3. Final Answer:

   driver.quit() is never called, so browser stays open after tests -> Option A

4. Quick Check:

   return ends function before cleanup [OK]

Hint: Use yield, not return, to ensure cleanup runs [OK]

Common Mistakes:

• Placing driver.quit() after return
• Using return instead of yield for fixtures
• Expecting cleanup code after return to run

5. You want to share a browser fixture in conftest.py that opens Chrome once per test session and closes it after all tests finish. Which fixture scope and code is correct?

hard

A. @pytest.fixture(scope='function')
def browser():
driver = webdriver.Chrome()
yield driver
driver.quit()

B. @pytest.fixture(scope='module')
def browser():
driver = webdriver.Chrome()
driver.quit()
yield driver

C. @pytest.fixture(scope='session')
def browser():
driver = webdriver.Chrome()
yield driver
driver.quit()

D. @pytest.fixture(scope='session')
def browser():
driver = webdriver.Chrome()
driver.quit()
yield driver

Solution

1. Step 1: Choose correct fixture scope for session-wide browser

   Using scope='session' makes the fixture run once per test session.

2. Step 2: Verify setup and teardown order with yield

   Driver is created before yield (browser opens), and driver.quit() runs after all tests finish.

3. Final Answer:

   @pytest.fixture(scope='session')\ndef browser():\n driver = webdriver.Chrome()\n yield driver\n driver.quit() -> Option C

4. Quick Check:

   scope='session' + yield = one browser per session [OK]

Hint: Use scope='session' and yield for one browser per session [OK]

Common Mistakes:

• Using scope='function' for session-wide browser
• Calling driver.quit() before yield
• Yielding after driver.quit()