Async fixtures (pytest-asyncio) - Build an Automation Script

Test async fixture setup and usage with pytest-asyncio

Preconditions (2)

Step 1: Create an async fixture that sets up a resource asynchronously

Step 2: Write an async test function that uses the async fixture

Step 3: Run the test with pytest

Step 4: Verify the async fixture is awaited and the test passes

✅ Expected Result: The test runs successfully using the async fixture without errors

Automation Requirements - pytest with pytest-asyncio

Assertions Needed:

Assert the async fixture returns the expected resource

Assert the async test function completes successfully

Best Practices:

Use @pytest_asyncio.fixture decorator for async fixtures

Use async def for fixture and test functions

Use await to call async functions inside fixtures and tests

Automated Solution

PyTest

import pytest
import pytest_asyncio

@pytest_asyncio.fixture
async def async_resource():
    # Simulate async setup
    await asyncio.sleep(0.1)
    return 'resource_ready'

@pytest.mark.asyncio
async def test_async_fixture_usage(async_resource):
    assert async_resource == 'resource_ready'

The code defines an async fixture async_resource using @pytest_asyncio.fixture. It simulates asynchronous setup by awaiting asyncio.sleep(0.1) and then returns a string.

The test function test_async_fixture_usage is marked with @pytest.mark.asyncio to allow async execution. It receives the fixture as a parameter and asserts the returned value is as expected.

This setup ensures the fixture is awaited properly and the test runs asynchronously without blocking.

Common Mistakes - 3 Pitfalls

Defining async fixture without @pytest_asyncio.fixture decorator

Not marking async test functions with @pytest.mark.asyncio

Calling async functions inside fixture or test without await

Bonus Challenge

Now add data-driven testing with 3 different async fixture setups returning different strings

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