Testing asynchronous Python code can be challenging, especially when dealing with nested context managers. In this tutorial, we’ll explore how to effectively mock nested async context managers to create clean, reliable tests for complex async code structures.

The Challenge of Testing Nested Async Context Managers

Modern Python codebases often use asynchronous context managers (using async with) for resource management in async functions. When these context managers are nested, testing becomes complicated. Consider a client that uses nested context managers to manage HTTP sessions and requests: