conftest.py

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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# tests/conftest.py
 
"""
pytest Session Configuration — oc_diagnostics
==============================================
 
Purpose
-------
Provide a single session-scoped pytest fixture that suppresses the one-shot
pre-init ``RuntimeWarning`` for the full pytest test session.
 
Background
----------
``unified_debug._dbg()`` emits a one-shot ``RuntimeWarning`` the first time it
is called before ``oc_diagnostics.init()`` has been called.  This is correct
and useful behaviour in production — but in the test suite, ``init()`` is
intentionally omitted from every test to avoid installing stream interceptors or
writing log files.  As a result, the first test that instantiates
``DiagnosticsMiddleware`` (or any other code that calls ``_dbg()`` at class
construction time) triggers the warning as a false positive.
 
``run_tests.py`` already handles this by setting ``_init_warned = True`` at the
top of ``main()``.  This ``conftest.py`` provides the equivalent suppression for
direct pytest invocations (e.g. ``pytest tests/``, ``pytest tests/test_fastapi_middleware.py``).
 
Effect on ``test_dbg_before_init_warning``
------------------------------------------
That test explicitly exercises the one-shot warning mechanism.  It saves
``_init_warned``, resets it to ``False`` in its own setup, and restores it in
``finally``.  The session fixture does not interfere because the test owns its
own state transitions.
 
Contracts
---------
- Must not start servers or modify persistent state.
- Must not suppress legitimate ``RuntimeWarning`` instances from production code.
- ``test_dbg_before_init_warning`` must continue to pass unchanged.
"""
 
import pytest
import oc_diagnostics.unified_debug as _ud
 
 
@pytest.fixture(autouse=True, scope="session")
def suppress_preinit_warning():
    """Suppress the one-shot pre-init RuntimeWarning for the full test session.
 
    Mirrors the ``_ud_runner._init_warned = True`` line at the top of
    ``run_tests.py main()``, ensuring consistent warning-free output whether
    tests are driven by ``python tests/run_tests.py`` or ``pytest tests/``.
    """
    _ud._init_warned = True