Async fixtures (pytest-asyncio) - Test Execution Trace

Test Overview

This test uses an async fixture to set up a resource before the test runs. It verifies that the async fixture provides the expected value to the test function.

Test Code - pytest-asyncio

PyTest

import pytest
import asyncio

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

@pytest.mark.asyncio
async def test_async_fixture(async_resource):
    assert async_resource == "resource_ready"

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts	pytest test runner initialized with pytest-asyncio plugin	-	PASS
2	pytest discovers test_async_fixture and async_resource fixture	Test and fixture functions loaded	-	PASS
3	pytest calls async_resource fixture asynchronously	async_resource fixture running, awaiting asyncio.sleep(0.1)	-	PASS
4	async_resource fixture returns value 'resource_ready'	Fixture setup complete, value ready for test	-	PASS
5	pytest calls test_async_fixture with async_resource value	Test function running with async_resource='resource_ready'	assert async_resource == 'resource_ready'	PASS
6	Test completes successfully	Test passed, no errors	-	PASS

Failure Scenario

Failing Condition: async_resource fixture returns incorrect value or raises exception

Execution Trace Quiz - 3 Questions

What does the async_resource fixture do before returning its value?

A Waits asynchronously for 0.1 seconds

B Runs a synchronous sleep for 0.1 seconds

C Immediately returns without delay

D Raises an exception

Key Result

Using async fixtures with pytest-asyncio allows setup of asynchronous resources before tests run, ensuring tests can await async operations properly.