Fixture factories in PyTest - Build an Automation Script

Automate user creation using fixture factory

Preconditions (2)

Step 1: Use the fixture factory to create a user with default attributes

Step 2: Use the fixture factory to create a user with a custom username 'testuser'

Step 3: Verify that the created user objects have the expected attributes

✅ Expected Result: The test should pass confirming that the fixture factory creates user objects correctly with default and custom attributes

Automation Requirements - pytest

Assertions Needed:

Assert default user has username 'defaultuser'

Assert custom user has username 'testuser'

Best Practices:

Use fixture factory pattern to generate test data

Keep fixtures modular and reusable

Use assert statements for validation

Avoid hardcoding test data inside tests

Automated Solution

PyTest

import pytest

class User:
    def __init__(self, username, email):
        self.username = username
        self.email = email

@pytest.fixture
def user_factory():
    def create_user(username='defaultuser', email='[e-mail]'):
        return User(username, email)
    return create_user

def test_user_creation(user_factory):
    default_user = user_factory()
    assert default_user.username == 'defaultuser'
    assert default_user.email == '[e-mail]'

    custom_user = user_factory(username='testuser', email='[e-mail]')
    assert custom_user.username == 'testuser'
    assert custom_user.email == '[e-mail]'

This test uses a fixture factory user_factory that returns a function to create User objects with default or custom attributes.

The test test_user_creation calls the factory twice: once with defaults and once with custom username and email.

Assertions check that the created users have the expected usernames and emails.

This pattern keeps test data creation flexible and reusable.

Common Mistakes - 3 Pitfalls

Defining fixture that returns a fixed user object instead of a factory function

Hardcoding user data inside the test instead of using the fixture factory

Not using assert statements to verify user attributes

Bonus Challenge

Now add data-driven testing with 3 different user inputs using the fixture factory

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