Files
langgraph/libs/checkpoint-postgres/tests
Elior Nataf LackritzandGitHub 658541c496 chore(checkpoint-postgres,checkpoint-sqlite): enable PLC0415 lint rule (#8540)
Follow-up to review on #8537: turn on ruff's `PLC0415`
(`import-outside-top-level`) so deferred imports in tests stop
accumulating.

Scoped to `checkpoint-postgres` and `checkpoint-sqlite` rather than
repo-wide, because the sweep turns up three different things and only
one of them is a style problem.

### What the rule finds today

```
package                 tests   src    files
checkpoint                13     10      11
checkpoint-conformance     0     10       4
checkpoint-postgres        6      0       2
checkpoint-sqlite          9      0       3
langgraph                130     23      32
prebuilt                  14      3       7
cli                        9     14      10
sdk-py                   189     23      38
                        ────────────────────
                         370     83     107
```

453 violations across 107 files, and ruff has no autofix for this rule.

### Three categories, not one

**Style — hoist.** `checkpoint-sqlite/tests/test_store.py` deferred
`math`, `random`, `time`, `Counter` and `defaultdict` inside methods for
no reason.

**Deliberate — keep, annotate.**
`checkpoint-postgres/tests/test_async.py` defers behind
`pytest.importorskip("langgraph.channels.delta")` because langgraph core
is *not* a test dependency of that package. Hoisting would break the
skip. Those get `# noqa: PLC0415` and a comment.

**Redundant guard — hoist.**
`checkpoint-sqlite/tests/test_conformance_delta.py` deferred imports
only to get past its own `importorskip`. Imports move up; the
`aiosqlite` guard stays, since that dependency genuinely can be absent.

The second category is why I did not enable this everywhere in one go.
Most of the 83 source-level violations look like the same pattern —
optional-dependency handling and circular-import avoidance in
`jsonplus.py`, `embed.py`, `encrypted.py` and friends. Blanket-enabling
would mean `# noqa` on a lot of correct code, and each one wants an
owner's eye rather than a mechanical pass.

These two packages are clean to enforce today because both have **zero**
source-level violations.

### Suggested rollout for the rest

Either extend package by package as owners confirm which deferrals are
intentional, or enable everywhere at once with `per-file-ignores`
grandfathering the current 107 files so new code is blocked immediately
and the debt burns down. Happy to do either — the second is a smaller
diff but leaves a long ignore list.

### Verified

`checkpoint-sqlite` 118 passed, `checkpoint-postgres` 264 passed on PG
15 and 16, `make lint` clean in both.

One overlap worth flagging:
`checkpoint-sqlite/tests/test_conformance_delta.py` is also touched by
#8537. The change is identical in both, so it should merge cleanly
either way.
2026-08-05 21:23:28 -04:00
..
2024-11-28 04:40:12 +00:00