Enable ruff argument, idiom and pytest-style rules (ARG, B, C4, FBT, PERF, PLW, PT, PTH, RUF, SIM and others)

.github/scripts/update_policyengine_package.py

@@ -83,8 +83,10 @@ def update_requirements(
         ),
     }
 
-    for location, dependencies in requirements.items():
-        dependencies = dependencies if isinstance(dependencies, list) else []
+    for location, declared_dependencies in requirements.items():
+        dependencies = (
+            declared_dependencies if isinstance(declared_dependencies, list) else []
+        )
         matches = [
             dependency
             for dependency in dependencies
@@ -140,7 +142,7 @@ def update_requirements(
     ) as temporary:
         temporary.write(text.replace(old_pin, new_pin))
         temporary_path = temporary.name
-    os.replace(temporary_path, pyproject)
+    Path(temporary_path).replace(pyproject)
 
 
 def find_issue(title: str) -> None:

AGENTS.md

@@ -142,15 +142,16 @@ To add or change a rule, read `docs/engineering/skills/rules-registry.md`.
 
 - `sim.quality.ci-cd-scripts-ruff-exemptions`: CI/CD scripts under .github may print their output (T201); every other ruff rule applies to them. (blocking: ruff per-file ignore of T201 for `.github/**`)
 - `sim.quality.command-line-scripts-ruff-exemptions`: Command-line scripts under a scripts directory may print their output (T201), run other programs (S603, S607) and use today's date (DTZ011); every other ruff rule applies to them. (blocking: ruff per-file ignore of DTZ011, S603, S607, T201 for `**/scripts/**`)
-- `sim.quality.deployed-tests-ruff-exemptions`: The deployed-service test suite (projects/*/authenticated_tests, pytest run against a live candidate) gets the same ruff exemptions as unit tests (sim.quality.tests-ruff-exemptions); every other ruff rule applies to it. (blocking: ruff per-file ignore of ANN, D1, DTZ001, DTZ007, INP001, PLC0415, PLR2004, S101, S102, S105, S106, S108, S301, S603, S607, SLF001, TID253 for `**/authenticated_tests/**`)
+- `sim.quality.deployed-tests-ruff-exemptions`: The deployed-service test suite (projects/*/authenticated_tests, pytest run against a live candidate) gets the same ruff exemptions as unit tests (sim.quality.tests-ruff-exemptions); every other ruff rule applies to it. (blocking: ruff per-file ignore of ANN, ARG001, ARG002, ARG005, D1, DTZ001, DTZ007, INP001, PLC0415, PLR2004, S101, S102, S105, S106, S108, S301, S603, S607, SLF001, TID253 for `**/authenticated_tests/**`)
 - `sim.quality.every-project-tested`: Every project and library with unit tests runs them in the PR test matrix. (doc-only, not checked: follow it yourself)
 - `sim.quality.ruff-format-src`: Source code under projects/*/src and libs/*/src is formatted with ruff format. (blocking: ruff format)
 - `sim.quality.ruff-format-tests`: Test code is formatted with ruff format too; CI currently checks only src directories. (doc-only, not checked: follow it yourself)
-- `sim.quality.ruff-lint`: All Python code passes ruff check with every rule family selected in ruff.toml, with no ratchet; families are added one themed group at a time until the selection is ALL. (blocking: ruff check (A, ANN, BLE, D, DTZ, E, E4, E7, E9, EM, ERA, EXE, F, FAST, FIX, FLY, FURB, G, I, INP, LOG, N, PIE, PLC, PYI, RET, RSE, S, SLF, T20, TC, TD, TID253, TRY, UP, W))
+- `sim.quality.ruff-lint`: All Python code passes ruff check with every rule family selected in ruff.toml, with no ratchet; families are added one themed group at a time until the selection is ALL. (blocking: ruff check (A, ANN, ARG, ASYNC, B, BLE, C4, D, DTZ, E, E4, E7, E9, EM, ERA, EXE, F, FAST, FBT, FIX, FLY, FURB, G, I, INP, LOG, N, PD, PERF, PGH, PIE, PLC, PLW, PT, PTH, PYI, RET, RSE, RUF, S, SIM, SLF, T20, TC, TD, TID253, TRY, UP, W))
 - `sim.quality.runtime-evaluated-models-resolve`: Every Pydantic model is runtime-evaluated for ruff: one of its bases, read through the imports of the model's own module, is listed in ruff.toml's runtime-evaluated-base-classes or is a runtime-evaluated class in that same module; and every Pydantic model resolves its annotations once its package is imported. (blocking: pytest `projects/policyengine-simulation-entry/tests/test_runtime_evaluated_annotations.py`, `projects/policyengine-simulation-executor/tests/test_runtime_evaluated_annotations.py`)
 - `sim.quality.src-programs-ruff-exemptions`: Programs under src (the Modal deployment utilities, and the OpenAPI and Stage 12 infrastructure commands) may print their output (T201), open URLs from their arguments (S310) and, for the Modal utilities run with python -m, live in a directory that isn't a package (INP001); every other ruff rule applies to them. (blocking: ruff per-file ignore of INP001, S310, T201 for `projects/*/src/{modal/utils/*,policyengine_simulation_entry/generate_openapi,policyengine_simulation_entry/stage12_infrastructure,policyengine_simulation_gateway/generate_openapi}.py`)
 - `sim.quality.tests-pass`: Each project's unit tests pass in its own locked environment. (blocking: CI job `test`)
-- `sim.quality.tests-ruff-exemptions`: Test files may use pytest's bare assert, need no docstrings, annotations or named constants for magic numbers, and may reach into private members, live outside packages and import inside a test (S101, D1, ANN, PLR2004, SLF001, INP001, PLC0415). They may also run repository scripts (S603, S607) and use fake credentials (S105, S106), temporary paths (S108), naive datetimes (DTZ001, DTZ007), pickle (S301) and exec (S102), and may import the lazily loaded packages at module level (TID253). Every other ruff rule applies to tests. (blocking: ruff per-file ignore of ANN, D1, DTZ001, DTZ007, INP001, PLC0415, PLR2004, S101, S102, S105, S106, S108, S301, S603, S607, SLF001, TID253 for `**/tests/**`)
+- `sim.quality.tests-ruff-exemptions`: Test files may use pytest's bare assert, need no docstrings, annotations or named constants for magic numbers, and may reach into private members, live outside packages and import inside a test (S101, D1, ANN, PLR2004, SLF001, INP001, PLC0415). They may also run repository scripts (S603, S607) and use fake credentials (S105, S106), temporary paths (S108), naive datetimes (DTZ001, DTZ007), pickle (S301) and exec (S102), may import the lazily loaded packages at module level (TID253), and may leave arguments unused in fakes and stubs that mirror a real signature (ARG001, ARG002, ARG005). Every other ruff rule applies to tests. (blocking: ruff per-file ignore of ANN, ARG001, ARG002, ARG005, D1, DTZ001, DTZ007, INP001, PLC0415, PLR2004, S101, S102, S105, S106, S108, S301, S603, S607, SLF001, TID253 for `**/tests/**`)
+- `sim.quality.unittest-ruff-exemptions`: The shared rules tool's tests use unittest, because the tool needs only the standard library, so ruff's pytest-style rules (PT) don't apply to them. (blocking: ruff per-file ignore of PT for `scripts/rules/tests/**`)
 
 ### CI workflows and scripts
 

changelog_entry.yaml

@@ -4,6 +4,7 @@
       - Made CLAUDE.md and the Copilot instructions thin pointers to AGENTS.md, required workflow logic longer than one line to live in tested and shellchecked scripts, and registered the tracking-issue rule
       - Added a rules registry (rules/registry.toml) with a standard-library tool that validates it, checks every rule is enforced where it claims, and renders docs/generated/rules.md and the Rules block in AGENTS.md
     changed:
+      - Enabled ruff's argument, idiom and pytest-style rules (ARG, ASYNC, B, C4, FBT, PD, PERF, PGH, PLW, PT, PTH, RUF, SIM); unused arguments are removed, underscored or explained, FastAPI auth dependencies use Annotated, re-raised errors keep their cause, and boolean options of in-repo helpers are keyword-only; OpenAPI documents are unchanged, and the shared rules tool's unittest tests are exempt from pytest-style rules; tests take the unused-argument rules (ARG001, ARG002, ARG005) as file-level exceptions, since their fakes and stubs mirror real signatures; best-effort telemetry and cleanup calls that swallow any error use contextlib.suppress, with the reason as a comment
       - Enabled ruff's structure and import rules (INP, PLC, SLF, N, A, FAST, E); long lines are wrapped, deferred imports that Modal images, test seams, import cycles or heavy dependencies need carry a reason, script directories are declared to ruff as namespace packages, four internal exceptions gained an Error suffix, and published field names, OpenAPI documents and logged error types are unchanged; tests are also exempt from SLF001, INP001 and PLC0415; heavy or optional packages that load only inside functions are listed in ruff's banned-module-level-imports, which keeps them out of module-level imports (TID253) and lets their deferred imports go without a suppression, and the Modal utility programs take INP001 file-wide
       - Enabled ruff's security, logging and debugging rules (S, T20, LOG, G, DTZ, ERA, TD, FIX, EXE); asserts outside tests became explicit checks, command-line scripts keep their printed output, test subprocess calls go through helpers, and every deliberate exception carries a reasoned suppression; the gateway's auth misconfiguration log no longer repeats its message, and the deployed-service tests share the unit-test ruff exemptions; tests, CI/CD scripts and command-line scripts take their deliberate exceptions as registered file-level ruff ignores instead of inline suppressions, and the rules guard rejects file-level ignores anywhere else
       - Enabled ruff's exception rules (TRY, EM, BLE); exception messages are built before the raise, raises inside try blocks moved into helpers, and every deliberate catch-all or traceback-free error log carries a reasoned suppression; message text is unchanged, and error types change only in an operator script's two type checks