feat(lint): cap comprehensions at one for and one if clause (LIT014) by devin-ai-integration[bot] · Pull Request #42650 · BerriAI/litellm

devin-ai-integration · 2026-09-23T02:06:26Z

TLDR

Problem this solves:

Comprehensions with stacked fors and ifs are hard to read
Nothing stopped new ones from landing

How it solves it:

New LIT014 rule in scripts/check_type_discipline.py
Flags any comprehension with more than one for or more than one if
Covers list, set, dict and generator expressions
Escape hatch: # comprehension-ok: <reason> on any line the comprehension spans (reasonless one trips LIT005, one that suppresses nothing trips LIT013)
Budget seeded at the current count (369), so no new ones can land

User Flow

Before: a contributor adds a two-for comprehension and lint stays green

They write [(a, b) for a in xs for b in ys if a if b] in a file under litellm/
They push and the "Type discipline gate" lint job passes
The reviewer has to catch the readability problem by hand

After: the same push fails lint with a message telling them how to fix it

They write the same comprehension
The lint job reports LIT014 comprehension with 2 \for` clauses and 2 `if` clauses: at most one of each is allowed. Split it into a helper generator, a named intermediate, or a plain loop (suppress: `# comprehension-ok: `)`
They split it into a helper generator or a plain loop, or add # comprehension-ok: <reason> when the stacked form is the clearest, and lint passes

Relevant issues

Affected release

Linear ticket

Pre-Submission checklist

Please complete all items before asking a LiteLLM maintainer to review your PR

I have added meaningful tests
The handful of test files covering my change pass locally, e.g. uv run pytest tests/test_litellm/<your_test_file>.py -v. Leave the suites (make test-unit-*, make test-unit) to CI: it finishes in ~15 minutes where a laptop takes an hour or more
My PR passes all required CI/CD checks (e.g., lint, schema.d.ts sync check, etc.)
My PR's scope is as isolated as possible; it only solves 1 specific problem
I have received a Greptile Confidence Score of at least 4/5 before requesting a maintainer review (Greptile reviews automatically once the PR is opened; only comment @greptileai to re-request a review after pushing changes)

Delays in PR merge?

If you're seeing a delay in your PR being merged, ping the LiteLLM Team on Slack (#pr-review).

Screenshots / Proof of Fix

This change is a lint rule, so the end-user surface is the checker and the gate, not the proxy. Video of the run below at tip d47f08c is posted in the Slack thread: https://berriaillm.slack.com/archives/C0B302ZJU05/p1790128816643949?thread_ts=1790128816.643949&cid=C0B302ZJU05

Shared setup:

printf 'pairs = [(a, b) for a in xs for b in ys if a if b]\nok = [a for a in xs if a]\n' > /tmp/lit013_snippet.py

Before (`37f5267`)

python3 scripts/check_type_discipline.py /tmp/lit013_snippet.py | grep -v LIT010
Output: only the pre-existing LIT002 findings on lines 1 and 2, nothing about the stacked clauses

/tmp/lit013_snippet.py:1: LIT002 mutable list comprehension: ...
/tmp/lit013_snippet.py:2: LIT002 mutable list comprehension: ...

After (`d47f08c`)

python3 scripts/check_type_discipline.py /tmp/lit013_snippet.py | grep -v LIT010
Output: line 1 now also trips LIT014, line 2 (one for, one if) does not

/tmp/lit013_snippet.py:1: LIT002 mutable list comprehension: ...
/tmp/lit013_snippet.py:1: LIT014 comprehension with 2 `for` clauses and 2 `if` clauses: at most one of each is allowed. Split it into a helper generator, a named intermediate, or a plain loop (suppress: `# comprehension-ok: <reason>`)
/tmp/lit013_snippet.py:2: LIT002 mutable list comprehension: ...

uv run --no-sync python scripts/type_discipline_gate.py --base origin/main
Output: OK: every LIT rule is within its codebase ceiling (base origin/main)

Type

🚄 Infrastructure

Caveats (if any)

Low

Seeding a limit is the one sanctioned budget edit on a branch, per the gate docstring
369 existing violations are grandfathered; the ratchet automation lowers the limit as they get fixed
The limit sits exactly at the current count, so any branch adding a stacked comprehension triggers the gate's base-worktree comparison scan before failing. Same shape as the LIT010 to LIT012 seeds
A # comprehension-ok marker on a line inside a multi-line violating comprehension suppresses only the innermost violating comprehension spanning that line plus any single-line violating one on it; a multi-line outer needs its own marker on a line the inner does not cover
An outer stacked comprehension whose every line is also covered by an inner stacked one has no line to carry its own marker, so it has to be reformatted or split rather than suppressed
The gate scans only litellm/, so the 4 stacked comprehensions under enterprise/ are neither counted nor gated; pre-existing gate scope, unchanged here
ruff check and ruff format --check on scripts/check_type_discipline.py fail identically on main (house format); the new code is format clean

Final Attestation

The tests check the right things, including the edge cases, and regressions in the respective real-world customer use-cases are not possible after this PR

Note

Low Risk
Lint-only infrastructure with no runtime or production behavior changes; existing violations are budget-grandfathered.

Overview
Adds LIT014 to the type-discipline linter: comprehensions (list/set/dict/generator) with more than one for or more than one if are flagged, with escape hatch # comprehension-ok: <reason> (wired into LIT005/LIT013 like other *-ok markers). The checker uses AST analysis with nuanced ownership rules so suppressions apply to the innermost violating comprehension on a line, not sibling/outer violations.

AGENTS.md documents the new style rule. type-discipline-budget.json seeds LIT014 at 369 (grandfathered count; gate blocks net-new violations). type_discipline_gate.py help text mentions the new suppression token. Tests cover clause counting, nested comprehensions, and suppression edge cases.

^{Reviewed by Cursor Bugbot for commit d47f08c. Bugbot is set up for automated code reviews on this repo. Configure here.}

Link to Devin session: https://app.devin.ai/sessions/adb960f503044c199f338d646b889b1b
Open in Devin Desktop: https://app.devin.ai/desktop/session/adb960f503044c199f338d646b889b1b?variant=devin
Requested by: @mateo-berri

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

devin-ai-integration · 2026-09-23T02:06:31Z

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

Disable automatic comment, CI, and merge conflict monitoring

greptile-apps · 2026-09-23T02:09:13Z

Confidence Score: 5/5

[Medium risk] Adds a new linting rule for comprehension complexity.

The PR appears safe to merge; no new actionable issue remains, and the latest revision fixes the prior untyped-test-parameter finding.

Summary

Adds the LIT014 type-discipline rule to prevent comprehensions with multiple for or multiple if clauses.

Supports reasoned # comprehension-ok suppressions across comprehension spans with nested-node ownership.
Adds the rule to the type-discipline gate and seeds its existing-code budget.
Documents the convention and adds regression coverage for comprehension forms, suppression placement, nesting, and clause counts.
The latest revision adds the required Path annotation to every newly introduced test parameter.

_{Reviews (7) · Last reviewed commit: "test(lint): type tmp_path in LIT014 test..."}

codecov · 2026-09-23T02:09:43Z

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

devin-ai-integration · 2026-09-23T02:19:06Z

@greptileai

…ning it Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

devin-ai-integration · 2026-09-23T02:31:33Z

@greptileai

…ension Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

devin-ai-integration · 2026-09-23T02:42:15Z

@greptileai

mateo-berri · 2026-09-23T02:51:58Z

bugbot run

cursor

Stale Bugbot comment from a previous run.

…number to LIT014)

…hension_clause_limit

mateo-berri · 2026-09-25T01:11:19Z

@greptileai

mateo-berri · 2026-09-25T01:11:20Z

bugbot run

cursor

Stale Bugbot comment from a previous run.

…rehension-ok markers Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

mateo-berri · 2026-09-25T01:23:02Z

@greptileai

mateo-berri · 2026-09-25T01:23:02Z

bugbot run

cursor

Stale Bugbot comment from a previous run.

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

mateo-berri · 2026-09-25T01:33:18Z

@greptileai

mateo-berri · 2026-09-25T01:33:19Z

bugbot run

cursor

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit d47f08c. Configure here.}

mateo-berri

LGTM

…_iterable LIT014 (#42650) caps a comprehension at one for and one if clause. The four nested walks in the helper now chain their iterables instead, with the same order and results.

…er (#42629) * ci: warn on SQL IN lists with no written bound Postgres caps a prepared statement at 32,767 bind parameters and a membership filter binds one per value, so an IN list built from table data breaks once the table outgrows the cap. That is how the budget reset job froze every due budget (LIT-7535, #40564). check_unbounded_in_lists.py reports every Prisma "in" / "not_in" filter whose value has no fixed size and every raw SQL literal that splices a list in after "IN (", unless the line carries "# bounded-ok: <reason>". It only warns for now: the output is the inventory for RCA action item AI-1, and it exits 0. * ci: decide a constant IN list by its module binding, not its casing An ALL_CAPS name imported or filled at runtime is as unbounded as any other, so a name now passes only when the module binds it once to a value of fixed size. Adds Final to the locals a loop does not forbid. * ci: only a frozen module value makes an IN list constant A module list bound once could still grow through append or extend, so a name now counts as fixed only when it is bound to a tuple, frozenset or constant. Trims the module docstring to what a reader needs. * ci: chunk Prisma IN lists with a shared helper and fail on new unbounded ones Add litellm.repositories.bounded_in: find_many_in, count_in, update_many_in and delete_many_in split a deduplicated value list into 5,000-value chunks, AND each chunk with the caller's where, run them in order (a transaction handle works) and combine the results. Writes take a required atomicity argument, and a where that already filters the chunked field is refused. check_unbounded_in_lists.py now fails CI on any finding missing from unbounded_in_baseline.txt and on any stale baseline entry, so the baseline only shrinks. Entries are keyed by path, enclosing scope, kind, field and occurrence, not line numbers. The helper module is exempt, a constant spread into a frozen tuple counts as fixed, and messages point at the helper for "in" and at an array parameter for "not_in" and raw SQL. A real-Postgres integration test shows a raw 40,000-value filter rejected for too many bind variables while the helpers handle it. * refactor: rename bounded_in to chunked_in and let callers pick a chunk size The helper module is litellm.repositories.chunked_in, and its unit and integration tests, the checker's exemption path and its finding messages follow the new name. The `# bounded-ok` marker is unchanged. find_many_in, count_in, update_many_in and delete_many_in take a keyword-only chunk_size, defaulting to IN_LIST_CHUNK_SIZE (5,000). A value below 1 or above MAX_IN_LIST_CHUNK_SIZE (30,000) raises ValueError before any query, which leaves the rest of the filter headroom under Postgres's 32,767 bind-parameter cap. * refactor: flatten chunked_in's stacked comprehensions with chain.from_iterable LIT014 (#42650) caps a comprehension at one for and one if clause. The four nested walks in the helper now chain their iterables instead, with the same order and results. * refactor: recover user details with find_many_in, sending chunks as lists _details_for_user_ids reads users through find_many_in instead of a raw "in" filter, so its lookup stays under the bind-parameter cap for any number of recovered keys. Up to 5,000 ids it still sends one find_many with the same where dict, and a PrismaError from any chunk is still logged and treated as no details. The helper now sends each chunk as a list, so a chunked filter equals the dict a hand-written call would send and a migrated call site's existing assertions keep passing. The site's baseline entry is gone. * ci: skip functional TypedDict field maps in the unbounded IN list check The dict passed as the field map of TypedDict("Name", {...}), or as its fields= keyword, names fields: an "in" or "notIn" key there is a type, not a filter. Only that dict is skipped, for TypedDict, typing.TypedDict and typing_extensions.TypedDict; a filter nested in a field value or passed to any other call is still reported. The two types/proxy/management_endpoints/team_endpoints.py entries leave the baseline, which is now 156. * fix: refuse an update_many_in whose data writes the chunked field Chunks run one after another, so an update that sets the chunked field can move a row into a later chunk, which updates it again and counts it twice: values ["old", "new"] with chunk_size=1 and data={"id": "new"} does exactly that. update_many_in now raises ChunkedFieldWriteError before any query when data has the chunked field as a top-level key, in any form, including Prisma operators such as {"set": ...}. * docs: cut the unbounded IN list checker's docstring to what it flags and how to clear it It now says what is reported, the three ways to clear a finding, and how the baseline and --update-baseline work, in 11 lines. The per-shape detail lives in the tests. * ci: key an unbounded IN list finding by its filtered expression too A baseline key of path, scope, kind, field and occurrence let a PR delete a baselined filter and add a different unbounded one on the same field in the same function, and the new one took over the old key. The key now also carries the filtered expression's source, whitespace-normalized (the Prisma value, or a raw-SQL `IN (...)` slot), so that swap reads as one new and one stale entry and fails the run. The same expression re-added in the same function is still the same finding. Every baseline entry is rewritten in the new form; the 156 findings are unchanged, and only occurrence indexes renumber where one field had several different expressions.

mateo-berri and others added 2 commits September 23, 2026 02:04

feat(lint): LIT013 caps comprehensions at one for and one if clause

bfc5778

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

docs(lint): rewrap the type discipline gate rule list

9d4d32a

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

devin-ai-integration Bot requested a review from a team September 23, 2026 02:06

devin-ai-integration Bot assigned mateo-berri Sep 23, 2026

devin-ai-integration Bot changed the title ~~feat(lint): LIT013 caps comprehensions at one for and one if clause~~ feat(lint): cap comprehensions at one for and one if clause (LIT013) Sep 23, 2026

greptile-apps Bot reviewed Sep 23, 2026

View reviewed changes

Comment thread scripts/check_type_discipline.py Outdated

Comment thread type-discipline-budget.json

fix(lint): honor comprehension-ok on any line a comprehension spans

c2bc11a

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

greptile-apps Bot reviewed Sep 23, 2026

View reviewed changes

Comment thread scripts/check_type_discipline.py Outdated

fix(lint): scope comprehension-ok to the innermost comprehension span…

87afc69

…ning it Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

greptile-apps Bot reviewed Sep 23, 2026

View reviewed changes

Comment thread scripts/check_type_discipline.py Outdated

Comment thread tests/test_litellm/test_check_type_discipline.py Outdated

fix(lint): break equal-span suppression ties toward the inner compreh…

5e83bda

…ension Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

cursor Bot reviewed Sep 23, 2026

View reviewed changes

devin-ai-integration Bot requested review from kerry-berri, mateo-berri, ryan-crabbe-berri and yuneng-berri as code owners September 25, 2026 01:07

mateo-berri added 2 commits September 25, 2026 01:08

merge: origin/main into litellm_lit013_comprehension_clause_limit (re…

adc00b0

…number to LIT014)

Merge remote-tracking branch 'origin/main' into litellm_lit013_compre…

b31ae1d

…hension_clause_limit

devin-ai-integration Bot force-pushed the litellm_lit013_comprehension_clause_limit branch from 9f5c9b5 to b31ae1d Compare September 25, 2026 01:08

devin-ai-integration Bot changed the title ~~feat(lint): cap comprehensions at one for and one if clause (LIT013)~~ feat(lint): cap comprehensions at one for and one if clause (LIT014) Sep 25, 2026

cursor Bot reviewed Sep 25, 2026

View reviewed changes

fix(lint): let single-line and only violating comprehensions own comp…

c20a557

…rehension-ok markers Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

greptile-apps Bot reviewed Sep 25, 2026

View reviewed changes

Comment thread tests/test_litellm/test_check_type_discipline.py Outdated

cursor Bot reviewed Sep 25, 2026

View reviewed changes

test(lint): type tmp_path in LIT014 tests

d47f08c

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

cursor Bot reviewed Sep 25, 2026

View reviewed changes

mateo-berri approved these changes Sep 25, 2026

View reviewed changes

mateo-berri merged commit 043331f into main Sep 25, 2026
99 checks passed

mateo-berri deleted the litellm_lit013_comprehension_clause_limit branch September 25, 2026 01:45

mateo-berri mentioned this pull request Oct 8, 2026

feat(lint): add LIT015 requiring pydantic models to be frozen #42348

Merged

5 of 7 tasks

Conversation

devin-ai-integration Bot commented Sep 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

TLDR

User Flow

Relevant issues

Affected release

Linear ticket

Pre-Submission checklist

Delays in PR merge?

Screenshots / Proof of Fix

Before (37f5267)

After (d47f08c)

Type

Caveats (if any)

Low

Final Attestation

Uh oh!

devin-ai-integration Bot commented Sep 23, 2026

Uh oh!

greptile-apps Bot commented Sep 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Confidence Score: 5/5

Summary

Uh oh!

Uh oh!

Uh oh!

codecov Bot commented Sep 23, 2026

Codecov Report

Uh oh!

devin-ai-integration Bot commented Sep 23, 2026

Uh oh!

Uh oh!

devin-ai-integration Bot commented Sep 23, 2026

Uh oh!

Uh oh!

Uh oh!

devin-ai-integration Bot commented Sep 23, 2026

Uh oh!

mateo-berri commented Sep 23, 2026

Uh oh!

cursor Bot left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

mateo-berri commented Sep 25, 2026

Uh oh!

mateo-berri commented Sep 25, 2026

Uh oh!

cursor Bot left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

mateo-berri commented Sep 25, 2026

Uh oh!

mateo-berri commented Sep 25, 2026

Uh oh!

Uh oh!

cursor Bot left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

mateo-berri commented Sep 25, 2026

Uh oh!

mateo-berri commented Sep 25, 2026

Uh oh!

cursor Bot left a comment

Choose a reason for hiding this comment

Uh oh!

mateo-berri left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

devin-ai-integration Bot commented Sep 23, 2026 •

edited

Loading

Before (`37f5267`)

After (`d47f08c`)

greptile-apps Bot commented Sep 23, 2026 •

edited

Loading

cursor Bot left a comment •

edited

Loading

cursor Bot left a comment •

edited

Loading

cursor Bot left a comment •

edited

Loading