ansible/docs/docsite/rst/dev_guide/testing/sanity/no-assert.rst

Sanity Tests » no-assert
========================

Do not use ``assert`` in production Ansible python code. When running Python
with optimizations, Python will remove ``assert`` statements, potentially
allowing for unexpected behavior throughout the Ansible code base.

Instead of using ``assert`` you should utilize simple ``if`` statements,
that result in raising an exception. There is a new exception called
``AnsibleAssertionError`` that inherits from ``AnsibleError`` and
``AssertionError``. When possible, utilize a more specific exception
than ``AnsibleAssertionError``.

Modules will not have access to ``AnsibleAssertionError`` and should instead
raise ``AssertionError``, a more specific exception, or just use
``module.fail_json`` at the failure point.