Async fixtures (pytest-asyncio) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an async fixture in pytest-asyncio?

An async fixture is a special setup function defined with async def that allows asynchronous setup and teardown in pytest tests using pytest-asyncio.

beginner

How do you declare an async fixture in pytest-asyncio?

Use the @pytest_asyncio.fixture decorator above an async def function to declare an async fixture.

intermediate

Why use async fixtures instead of regular fixtures?

Async fixtures let you run asynchronous setup code like opening async database connections or starting async servers, which regular fixtures cannot do.

beginner

How do you use an async fixture in a test function?

Simply add the fixture name as a parameter to an async def test function. pytest-asyncio will await the fixture automatically.

intermediate

What happens if you try to use an async fixture in a regular (non-async) test function?

The test will fail because pytest cannot await the async fixture in a synchronous test function. The test must be async to use async fixtures.

Which decorator is used to create an async fixture in pytest-asyncio?

A @pytest.fixture

B @pytest_async.fixture

C @asyncio.fixture

D @pytest_asyncio.fixture

The correct decorator for async fixtures in pytest-asyncio is @pytest_asyncio.fixture.

What must a test function be to use an async fixture?

A A regular def function

B A static method

C An async def function

D A class method

The test function must be declared with async def so pytest-asyncio can await async fixtures.

What is a common use case for async fixtures?

A Setting up async database connections

B Running CPU-bound tasks

C Opening synchronous files

D Printing debug messages

Async fixtures are often used to set up asynchronous resources like database connections.

What happens if you forget to await an async fixture in your test?

A The test passes silently

B The test fails with an error

C The fixture runs synchronously

D The test is skipped

If an async fixture is not awaited properly, pytest will raise an error because it expects an awaitable.

Which pytest plugin enables async fixtures?

A pytest-asyncio

B pytest-mock

C pytest-cov

D pytest-xdist

The pytest-asyncio plugin provides support for async fixtures and async test functions.

Explain how to create and use an async fixture in pytest-asyncio.

Think about the decorator, async function, and how tests receive the fixture.

Describe why async fixtures are important in testing asynchronous code.

Consider what async fixtures help manage in tests.