Files
siftlode/backend/tests/test_override_dep_convention.py
T
peter a5fae489e0 test: a request that raises is rolled back, as production rolls it back
The shared test session kept whatever a failing handler flushed and never
committed, so a later read in the test saw a write production loses when
get_db closes the session — and a handler whose failure path must commit
(E16: the tracker's issue link) looked right without the commit.
2026-09-19 22:48:20 +02:00

85 lines
3.8 KiB
Python

"""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)
def test_the_commit_check_counts_only_the_root_transaction(db):
"""A savepoint released inside a handler commits nothing to the database; ending it must not
clear the check (round 2). Driven directly, as a request would drive the dependency."""
import pytest
from starlette.requests import HTTPConnection
from app.models import User
conn = HTTPConnection(
{"type": "http", "method": "POST", "path": "/probe", "headers": [], "query_string": b""}
)
request = db.info["request"](conn)
session = next(request)
session.add(User(email="savepoint-probe@example.com"))
session.flush()
with session.begin_nested():
pass
with pytest.raises(StopIteration):
next(request)
assert db.info["unfinished"] == ["POST /probe"]
db.info["unfinished"].clear() # recorded as it should be — not this test's failure
def test_a_request_that_raises_leaves_nothing_it_did_not_commit(db):
"""Production closes a failing request's session, which rolls back whatever it flushed and did
not commit; the shared test session must do the same, or a later read in the test sees a write
production would have lost (E16: the tracker's issue link, kept only by an explicit commit in
the handler's failure path). Driven directly, as a request would drive the dependency."""
import pytest
from sqlalchemy import select
from starlette.requests import HTTPConnection
from app.models import User
conn = HTTPConnection(
{"type": "http", "method": "POST", "path": "/probe", "headers": [], "query_string": b""}
)
request = db.info["request"](conn)
session = next(request)
session.add(User(email="rolled-back-probe@example.com"))
session.flush()
with pytest.raises(RuntimeError):
request.throw(RuntimeError("the handler failed"))
assert db.scalar(select(User).where(User.email == "rolled-back-probe@example.com")) is None
assert db.info["unfinished"] == [] # a failing request is rolled back, not reported