"""Dependency overrides go through `conftest.override_dep`, never `app.dependency_overrides` directly. The hand-rolled shape — assign, then `app.dependency_overrides.clear()` in a `finally` — wipes EVERY override, not the ones the test set, so it stops fixtures composing: one test's teardown silently clobbers an override another fixture installed. `override_dep` restores each key's prior value instead. 22 files had drifted to the hand-rolled shape (it was the house norm at ~20 files to 3), and the sweep that converted them is only as good as the check that keeps it converted — this one. """ from pathlib import Path TESTS = Path(__file__).parent def test_no_test_writes_dependency_overrides_directly(): offenders = [ f"{p.name}:{n}" for p in sorted(TESTS.rglob("*.py")) if p.name not in {"conftest.py", Path(__file__).name} for n, line in enumerate(p.read_text(encoding="utf-8").splitlines(), 1) if "dependency_overrides" in line ] assert offenders == [], "use the override_dep fixture: " + ", ".join(offenders) def test_a_request_gets_the_session_that_checks_its_commit(): """`get_db` is overridden with `db.info["request"]` — the test session plus the check that the handler committed what it flushed (conftest `_request_dep`). A bare `lambda: db` hands the route the same session without the check, and a handler that forgot its commit passes again.""" offenders = [ f"{p.name}:{n}" for p in sorted(TESTS.rglob("*.py")) if p.name != Path(__file__).name for n, line in enumerate(p.read_text(encoding="utf-8").splitlines(), 1) if "override_dep(get_db," in line and 'override_dep(get_db, db.info["request"])' not in line ] assert offenders == [], 'override get_db with db.info["request"]: ' + ", ".join(offenders)