Database fixture patterns in PyTest - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a database fixture in pytest?

A database fixture in pytest is a setup function that prepares a test database environment before tests run and cleans it up afterward. It helps tests run with consistent data and state.

beginner

Why use database fixtures instead of creating data inside each test?

Using database fixtures avoids repeating setup code in every test. It ensures tests start with a known database state, making tests faster, cleaner, and easier to maintain.

intermediate

What is the difference between function-scoped and session-scoped database fixtures?

Function-scoped fixtures run before and after each test function, giving a fresh database state every time. Session-scoped fixtures run once per test session, sharing the same database state across tests.

intermediate

How can you ensure database changes made during a test do not affect other tests?

You can use transactions that roll back after each test or recreate the database state using fixtures to isolate tests and keep the database clean.

beginner

What is a common pattern to load initial test data using pytest fixtures?

A common pattern is to create a fixture that inserts known test data into the database before tests run, so tests can rely on this data without setting it up themselves.

What does a pytest database fixture typically do?

A Generate user interface elements

B Compile the application code

C Set up and tear down database state for tests

D Send emails during tests

Database fixtures prepare the database before tests and clean it after, ensuring consistent test environments.

Which fixture scope gives a fresh database state for each test function?

A Function scope

B Session scope

C Module scope

D Class scope

Function-scoped fixtures run before each test function, providing a clean database state every time.

How can pytest fixtures help avoid test interference in database tests?

A By sharing the same database state for all tests

B By isolating tests with setup and teardown steps

C By disabling the database during tests

D By running tests in parallel without setup

Fixtures isolate tests by preparing and cleaning the database, preventing one test's changes from affecting others.

What is a benefit of using session-scoped database fixtures?

A They speed up tests by reusing setup

B They run before every test function

C They create a new database for each test

D They disable database access

Session-scoped fixtures run once per test session, reducing setup time by reusing the database state.

What is a common way to reset database changes after a test?

A Restart the computer

B Ignore database changes

C Delete the test code

D Use transactions with rollback

Using transactions that roll back after tests keeps the database clean and ready for the next test.

Explain how database fixtures help maintain test isolation in pytest.

Think about how tests share or reset data.

Describe the difference between function-scoped and session-scoped database fixtures and when to use each.

Consider test speed versus data freshness.