Async Python Testing for AOS

Description

Expert knowledge for testing asynchronous Python code in the Agent Operating System. AOS is heavily async-based, and proper async testing patterns are critical for reliable tests.

When to Use This Skill

•Writing tests for async functions
•Testing async generators and iterators
•Mocking async calls and services
•Debugging async test failures
•Understanding pytest-asyncio patterns
•Testing concurrent operations

Key Concepts

Why Async in AOS?

AOS uses async/await extensively because:

•Azure SDK is async-based
•I/O operations (network, storage) benefit from async
•Agent orchestration requires concurrent operations
•Better resource utilization for perpetual agents

Async vs Sync Testing

python

# Sync test (traditional)
def test_something():
    result = function()
    assert result == expected

# Async test (AOS)
@pytest.mark.asyncio
async def test_something_async():
    result = await async_function()
    assert result == expected

Testing Patterns

Basic Async Test

python

import pytest

@pytest.mark.asyncio
async def test_basic_async():
    """Simple async test."""
    async def fetch_data():
        return "data"
    
    result = await fetch_data()
    assert result == "data"

Testing Async Functions with Setup/Teardown

python

import pytest

@pytest.mark.asyncio
async def test_with_setup_teardown():
    """Test with async setup and teardown."""
    # Setup
    agent = MyAgent()
    await agent.initialize()
    
    try:
        # Test
        result = await agent.process()
        assert result is not None
        
    finally:
        # Teardown
        await agent.cleanup()

Using Fixtures

python

import pytest

@pytest.fixture
async def initialized_agent():
    """Async fixture for agent."""
    agent = MyAgent()
    await agent.initialize()
    yield agent
    await agent.cleanup()

@pytest.mark.asyncio
async def test_with_fixture(initialized_agent):
    """Test using async fixture."""
    result = await initialized_agent.process()
    assert result is not None

Testing Multiple Async Operations

python

import pytest
import asyncio

@pytest.mark.asyncio
async def test_concurrent_operations():
    """Test multiple concurrent async operations."""
    async def operation_1():
        await asyncio.sleep(0.1)
        return "op1"
    
    async def operation_2():
        await asyncio.sleep(0.1)
        return "op2"
    
    # Run concurrently
    results = await asyncio.gather(
        operation_1(),
        operation_2()
    )
    
    assert results == ["op1", "op2"]

Mocking Async Code

Mocking Async Functions

python

import pytest
from unittest.mock import AsyncMock, MagicMock

@pytest.mark.asyncio
async def test_with_async_mock():
    """Test with AsyncMock."""
    # Create mock
    mock_service = AsyncMock()
    mock_service.fetch_data.return_value = {"data": "test"}
    
    # Use mock
    result = await mock_service.fetch_data()
    assert result == {"data": "test"}
    
    # Verify call
    mock_service.fetch_data.assert_called_once()

Mocking Azure Services

python

import pytest
from unittest.mock import AsyncMock, patch

@pytest.mark.asyncio
async def test_with_mocked_azure():
    """Test with mocked Azure services."""
    with patch('azure.storage.blob.BlobServiceClient') as mock_blob:
        # Configure mock
        mock_client = AsyncMock()
        mock_blob.from_connection_string.return_value = mock_client
        mock_client.get_blob_client.return_value.download_blob.return_value = b"data"
        
        # Test code that uses Azure Blob
        from AgentOperatingSystem.storage import AzureBlobStorage
        storage = AzureBlobStorage("connection_string")
        data = await storage.download("container", "blob")
        
        assert data == b"data"

Mocking Async Context Managers

python

import pytest
from unittest.mock import AsyncMock

@pytest.mark.asyncio
async def test_async_context_manager():
    """Test async context manager."""
    mock_resource = AsyncMock()
    mock_resource.__aenter__.return_value = mock_resource
    mock_resource.__aexit__.return_value = None
    mock_resource.do_something.return_value = "result"
    
    async with mock_resource as resource:
        result = await resource.do_something()
        assert result == "result"
    
    mock_resource.__aenter__.assert_called_once()
    mock_resource.__aexit__.assert_called_once()

Testing AOS Components

Testing Perpetual Agents

python

import pytest
from AgentOperatingSystem.agents import GenericPurposeDrivenAgent

@pytest.mark.asyncio
async def test_perpetual_agent():
    """Test perpetual agent lifecycle."""
    agent = GenericPurposeDrivenAgent(
        agent_id="test",
        purpose="Testing",
        adapter_name="test"
    )
    
    # Initialize
    await agent.initialize()
    assert agent.context_server is not None
    
    # Test operation
    event = {"type": "test_event"}
    result = await agent.handle_event(event)
    
    # Cleanup
    await agent.cleanup()

Testing Agent Orchestration

python

import pytest
from AgentOperatingSystem.orchestration import AgentOrchestrator

@pytest.mark.asyncio
async def test_orchestration():
    """Test agent orchestration."""
    orchestrator = AgentOrchestrator()
    await orchestrator.initialize()
    
    try:
        # Register agents
        agent1 = create_test_agent("agent1")
        agent2 = create_test_agent("agent2")
        
        await orchestrator.register_agent(agent1)
        await orchestrator.register_agent(agent2)
        
        # Test orchestration
        result = await orchestrator.coordinate_agents(
            task="test_task"
        )
        
        assert result is not None
        
    finally:
        await orchestrator.cleanup()

Testing Message Bus

python

import pytest
from AgentOperatingSystem.messaging import MessageBus

@pytest.mark.asyncio
async def test_message_bus():
    """Test async message bus."""
    bus = MessageBus()
    await bus.initialize()
    
    received_messages = []
    
    async def message_handler(message):
        received_messages.append(message)
    
    # Subscribe
    await bus.subscribe("test_topic", message_handler)
    
    # Publish
    await bus.publish("test_topic", {"data": "test"})
    
    # Wait for processing
    await asyncio.sleep(0.1)
    
    # Verify
    assert len(received_messages) == 1
    assert received_messages[0]["data"] == "test"
    
    await bus.cleanup()

Common Patterns

Testing Timeouts

python

import pytest
import asyncio

@pytest.mark.asyncio
async def test_with_timeout():
    """Test operation with timeout."""
    async def slow_operation():
        await asyncio.sleep(10)
        return "done"
    
    # Test that operation times out
    with pytest.raises(asyncio.TimeoutError):
        await asyncio.wait_for(slow_operation(), timeout=0.1)

Testing Retries

python

import pytest
from unittest.mock import AsyncMock

@pytest.mark.asyncio
async def test_retry_logic():
    """Test retry mechanism."""
    mock_service = AsyncMock()
    
    # Fail twice, then succeed
    mock_service.call.side_effect = [
        Exception("Error 1"),
        Exception("Error 2"),
        "success"
    ]
    
    # Function with retry logic
    async def call_with_retry(max_retries=3):
        for attempt in range(max_retries):
            try:
                return await mock_service.call()
            except Exception:
                if attempt == max_retries - 1:
                    raise
                await asyncio.sleep(0.1)
    
    result = await call_with_retry()
    assert result == "success"
    assert mock_service.call.call_count == 3

Testing Async Generators

python

import pytest

@pytest.mark.asyncio
async def test_async_generator():
    """Test async generator."""
    async def async_range(n):
        for i in range(n):
            await asyncio.sleep(0.01)
            yield i
    
    results = []
    async for value in async_range(3):
        results.append(value)
    
    assert results == [0, 1, 2]

Testing Error Handling

python

import pytest

@pytest.mark.asyncio
async def test_error_handling():
    """Test async error handling."""
    async def failing_function():
        raise ValueError("Test error")
    
    # Test that error is raised
    with pytest.raises(ValueError, match="Test error"):
        await failing_function()

Pytest Configuration

pytest.ini or pyproject.toml

ini

[pytest]
asyncio_mode = auto
testpaths = tests
python_files = test_*.py
python_classes = Test*
python_functions = test_*
markers =
    asyncio: async tests
    integration: integration tests
    unit: unit tests

Running Async Tests

bash

# Run all async tests
pytest tests/ -v

# Run with asyncio mode auto
pytest tests/ --asyncio-mode=auto

# Run specific async test
pytest tests/test_perpetual_agents.py::test_agent_initialization -v

# Run with markers
pytest -m asyncio tests/

# Show async warnings
pytest tests/ -v -W default

Common Issues and Solutions

Issue: "RuntimeError: Event loop is closed"

Problem: Event loop closed prematurely.

Solution:

python

# Use pytest-asyncio which manages event loop
@pytest.mark.asyncio
async def test_function():
    # pytest-asyncio handles event loop
    result = await async_operation()
    assert result

Issue: "coroutine was never awaited"

Problem: Forgot to await async function.

Solution:

python

# Wrong
result = async_function()  # Returns coroutine, not result

# Correct
result = await async_function()

Issue: Tests Hang Indefinitely

Problem: Awaiting something that never completes.

Solution:

python

# Add timeout
@pytest.mark.asyncio
async def test_with_timeout():
    async with asyncio.timeout(5):  # Python 3.11+
        result = await potentially_hanging_operation()
    
    # Or for older Python
    result = await asyncio.wait_for(
        potentially_hanging_operation(),
        timeout=5.0
    )

Issue: "Task was destroyed but it is pending"

Problem: Tasks not properly cleaned up.

Solution:

python

@pytest.mark.asyncio
async def test_cleanup():
    task = asyncio.create_task(background_operation())
    
    try:
        # Test code
        await something()
    finally:
        # Cleanup
        task.cancel()
        try:
            await task
        except asyncio.CancelledError:
            pass

Issue: Mocks Not Working with Async

Problem: Using MagicMock instead of AsyncMock.

Solution:

python

# Wrong
mock = MagicMock()
await mock.async_method()  # Will fail

# Correct
mock = AsyncMock()
await mock.async_method()  # Works correctly

Best Practices

•Always use @pytest.mark.asyncio: Mark all async tests
•Use AsyncMock for async mocks: Not regular MagicMock
•Clean up resources: Use try/finally or fixtures
•Test both success and failure: Cover error paths
•Use timeouts: Prevent hanging tests
•Avoid blocking calls: Use async alternatives
•Test concurrent scenarios: Use asyncio.gather
•Mock external services: Don't rely on real Azure/network
•Use fixtures for setup: Reuse common setup code
•Test cancellation: Verify cleanup on task cancellation

Example Test File

python

"""
Test module for async agent operations.
"""
import pytest
import asyncio
from unittest.mock import AsyncMock
from AgentOperatingSystem.agents import GenericPurposeDrivenAgent


@pytest.fixture
async def test_agent():
    """Create test agent."""
    agent = GenericPurposeDrivenAgent(
        agent_id="test",
        purpose="Testing",
        adapter_name="test"
    )
    await agent.initialize()
    yield agent
    await agent.cleanup()


@pytest.mark.asyncio
async def test_agent_initialization(test_agent):
    """Test agent initializes correctly."""
    assert test_agent is not None
    assert test_agent.agent_id == "test"
    assert test_agent.context_server is not None


@pytest.mark.asyncio
async def test_agent_event_processing(test_agent):
    """Test agent processes events."""
    event = {"type": "test", "data": "test"}
    result = await test_agent.handle_event(event)
    assert result is not None


@pytest.mark.asyncio
async def test_concurrent_agents():
    """Test multiple agents running concurrently."""
    agents = []
    
    try:
        # Create multiple agents
        for i in range(3):
            agent = GenericPurposeDrivenAgent(
                agent_id=f"agent_{i}",
                purpose=f"Purpose {i}",
                adapter_name="test"
            )
            await agent.initialize()
            agents.append(agent)
        
        # Process events concurrently
        events = [{"type": "test", "id": i} for i in range(3)]
        results = await asyncio.gather(*[
            agent.handle_event(event)
            for agent, event in zip(agents, events)
        ])
        
        assert len(results) == 3
        
    finally:
        # Cleanup all agents
        await asyncio.gather(*[
            agent.cleanup() for agent in agents
        ])


@pytest.mark.asyncio
async def test_error_handling():
    """Test agent error handling."""
    agent = GenericPurposeDrivenAgent(
        agent_id="test",
        purpose="Testing",
        adapter_name="test"
    )
    
    # Mock to raise error
    agent.process_event = AsyncMock(side_effect=ValueError("Test error"))
    
    with pytest.raises(ValueError, match="Test error"):
        await agent.process_event({})

File Locations

Test Files

•tests/ - All test files
•tests/test_perpetual_agents.py - Perpetual agent tests
•tests/test_integration.py - Integration tests
•tests/test_azure_functions_infrastructure.py - Azure Functions tests

Configuration

•pyproject.toml - pytest configuration
•pytest.ini - Alternative pytest configuration

Related Skills

•perpetual-agents - Testing perpetual agents
•azure-functions - Testing Azure Functions
•mocking-azure - Mocking Azure services

Additional Resources

•pytest-asyncio documentation
•Python asyncio documentation
•unittest.mock.AsyncMock
•tests/ directory - Real-world examples