[ruff] Add fix for `none-not-at-end-of-union` (RUF036) by anishgirianish · Pull Request #22829 · astral-sh/ruff

anishgirianish · 2026-01-24T04:02:46Z

Summary

Adds an autofix for RUF036 that moves None to the end of union type annotations.

Closes #15136

The fix:

Preserves the union style (PEP 604 | vs typing.Union)
Preserves duplicate None values instead of deduplicating
Skips nested unions to avoid flattening (e.g., None | Union[int, str])
Marked unsafe when comments are present in the annotation

Test Plan

cargo nextest run -p ruff_linter - added test cases for nested unions, comments,
default arguments, and mixed styles.

crates/ruff_linter/src/rules/ruff/rules/none_not_at_end_of_union.rs

anishgirianish · 2026-02-14T07:33:37Z

@amyreese Thanks for the review! I've addressed all the feedback:

Changed "type annotation" to "type union" in the message and fix title
Refactored generate_pep604_fix and generate_typing_union_fix to return Edit, building the Fix in generate_fix
Removed .copied() by simplifying to [other_exprs, none_exprs].concat()

Ready for another look whenever you have a chance. Thank you!

astral-sh-bot · 2026-02-14T07:36:07Z

`ruff-ecosystem` results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

ℹ️ ecosystem check detected linter changes. (+367 -367 violations, +0 -0 fixes in 18 projects; 38 projects unchanged)

DisnakeDev/disnake (+10 -10 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview

+ disnake/gateway.py:287:37: RUF036 [*] `None` not at the end of the type union.
- disnake/gateway.py:287:43: RUF036 `None` not at the end of the type annotation.
+ disnake/i18n.py:103:15: RUF036 [*] `None` not at the end of the type union.
- disnake/i18n.py:103:35: RUF036 `None` not at the end of the type annotation.
+ disnake/i18n.py:113:15: RUF036 [*] `None` not at the end of the type union.
- disnake/i18n.py:113:35: RUF036 `None` not at the end of the type annotation.
+ disnake/i18n.py:137:44: RUF036 [*] `None` not at the end of the type union.
- disnake/i18n.py:137:50: RUF036 `None` not at the end of the type annotation.
+ disnake/i18n.py:30:37: RUF036 [*] `None` not at the end of the type union.
- disnake/i18n.py:30:43: RUF036 `None` not at the end of the type annotation.
... 10 additional changes omitted for project

RasaHQ/rasa (+3 -3 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview

+ rasa/shared/core/events.py:597:42: RUF036 [*] `None` not at the end of the type union.
- rasa/shared/core/events.py:597:48: RUF036 `None` not at the end of the type annotation.
+ rasa/shared/core/events.py:624:25: RUF036 [*] `None` not at the end of the type union.
- rasa/shared/core/events.py:624:31: RUF036 `None` not at the end of the type annotation.
+ rasa/utils/tensorflow/models.py:247:29: RUF036 [*] `None` not at the end of the type union.
- rasa/utils/tensorflow/models.py:247:35: RUF036 `None` not at the end of the type annotation.

apache/airflow (+105 -105 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview --select ALL

+ airflow-core/src/airflow/api_fastapi/common/parameters.py:1086:22: RUF036 [*] `None` not at the end of the type union.
- airflow-core/src/airflow/api_fastapi/common/parameters.py:1086:22: RUF036 `None` not at the end of the type annotation.
+ airflow-core/src/airflow/api_fastapi/common/parameters.py:203:20: RUF036 [*] `None` not at the end of the type union.
- airflow-core/src/airflow/api_fastapi/common/parameters.py:203:20: RUF036 `None` not at the end of the type annotation.
+ airflow-core/src/airflow/api_fastapi/common/parameters.py:206:22: RUF036 [*] `None` not at the end of the type union.
- airflow-core/src/airflow/api_fastapi/common/parameters.py:206:22: RUF036 `None` not at the end of the type annotation.
+ airflow-core/src/airflow/api_fastapi/common/parameters.py:210:26: RUF036 [*] `None` not at the end of the type union.
- airflow-core/src/airflow/api_fastapi/common/parameters.py:210:26: RUF036 `None` not at the end of the type annotation.
+ airflow-core/src/airflow/api_fastapi/core_api/routes/public/auth.py:38:65: RUF036 [*] `None` not at the end of the type union.
- airflow-core/src/airflow/api_fastapi/core_api/routes/public/auth.py:38:65: RUF036 `None` not at the end of the type annotation.
+ airflow-core/src/airflow/example_dags/plugins/event_listener.py:102:12: RUF036 [*] `None` not at the end of the type union.
- airflow-core/src/airflow/example_dags/plugins/event_listener.py:102:12: RUF036 `None` not at the end of the type annotation.
+ airflow-core/src/airflow/executors/base_executor.py:155:13: RUF036 [*] `None` not at the end of the type union.
- airflow-core/src/airflow/executors/base_executor.py:155:13: RUF036 `None` not at the end of the type annotation.
... 196 additional changes omitted for project

apache/superset (+2 -2 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview --select ALL

+ superset/db_engine_specs/gsheets.py:310:26: RUF036 [*] `None` not at the end of the type union.
- superset/db_engine_specs/gsheets.py:310:26: RUF036 `None` not at the end of the type annotation.
+ superset/jinja_context.py:101:10: RUF036 [*] `None` not at the end of the type union.
- superset/jinja_context.py:101:16: RUF036 `None` not at the end of the type annotation.

bokeh/bokeh (+3 -3 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview --select ALL

+ src/bokeh/client/websocket.py:73:85: RUF036 [*] `None` not at the end of the type union.
- src/bokeh/client/websocket.py:73:85: RUF036 `None` not at the end of the type annotation.
+ src/bokeh/embed/standalone.py:84:24: RUF036 [*] `None` not at the end of the type union.
- src/bokeh/embed/standalone.py:84:30: RUF036 `None` not at the end of the type annotation.
+ src/bokeh/util/tornado.py:231:26: RUF036 [*] `None` not at the end of the type union.
- src/bokeh/util/tornado.py:231:26: RUF036 `None` not at the end of the type annotation.

ibis-project/ibis (+2 -2 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview

+ ibis/backends/__init__.py:1294:54: RUF036 [*] `None` not at the end of the type union.
- ibis/backends/__init__.py:1294:54: RUF036 `None` not at the end of the type annotation.
+ ibis/backends/sql/__init__.py:725:43: RUF036 [*] `None` not at the end of the type union.
- ibis/backends/sql/__init__.py:725:43: RUF036 `None` not at the end of the type annotation.

langchain-ai/langchain (+10 -10 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview

+ libs/langchain/langchain_classic/evaluation/parsing/base.py:152:10: RUF036 [*] `None` not at the end of the type union.
- libs/langchain/langchain_classic/evaluation/parsing/base.py:152:24: RUF036 `None` not at the end of the type annotation.
+ libs/langchain/langchain_classic/evaluation/parsing/json_distance.py:94:41: RUF036 [*] `None` not at the end of the type union.
- libs/langchain/langchain_classic/evaluation/parsing/json_distance.py:94:55: RUF036 `None` not at the end of the type annotation.
+ libs/langchain/langchain_classic/evaluation/parsing/json_schema.py:67:41: RUF036 [*] `None` not at the end of the type union.
- libs/langchain/langchain_classic/evaluation/parsing/json_schema.py:67:55: RUF036 `None` not at the end of the type annotation.
+ libs/langchain/langchain_classic/indexes/_sql_record_manager.py:93:17: RUF036 [*] `None` not at the end of the type union.
- libs/langchain/langchain_classic/indexes/_sql_record_manager.py:93:17: RUF036 `None` not at the end of the type annotation.
+ libs/langchain_v1/langchain/agents/middleware/types.py:806:10: RUF036 [*] `None` not at the end of the type union.
- libs/langchain_v1/langchain/agents/middleware/types.py:806:42: RUF036 `None` not at the end of the type annotation.
... 10 additional changes omitted for project

latchbio/latch (+5 -5 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview

+ src/latch/registry/types.py:38:43: RUF036 [*] `None` not at the end of the type union.
- src/latch/registry/types.py:47:5: RUF036 `None` not at the end of the type annotation.
+ src/latch_cli/services/get.py:38:26: RUF036 [*] `None` not at the end of the type union.
- src/latch_cli/services/get.py:38:32: RUF036 `None` not at the end of the type annotation.
+ src/latch_cli/snakemake/config/utils.py:200:50: RUF036 [*] `None` not at the end of the type union.
- src/latch_cli/snakemake/config/utils.py:200:56: RUF036 `None` not at the end of the type annotation.
+ src/latch_cli/snakemake/config/utils.py:25:24: RUF036 [*] `None` not at the end of the type union.
- src/latch_cli/snakemake/config/utils.py:25:53: RUF036 `None` not at the end of the type annotation.
+ src/latch_sdk_gql/utils.py:37:28: RUF036 [*] `None` not at the end of the type union.
- src/latch_sdk_gql/utils.py:38:59: RUF036 `None` not at the end of the type annotation.

milvus-io/pymilvus (+1 -1 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview

+ pymilvus/client/search_result.py:888:51: RUF036 [*] `None` not at the end of the type union.
- pymilvus/client/search_result.py:888:57: RUF036 `None` not at the end of the type annotation.

pandas-dev/pandas (+28 -28 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview

+ pandas/_libs/json.pyi:14:22: RUF036 [*] `None` not at the end of the type union.
- pandas/_libs/json.pyi:14:22: RUF036 `None` not at the end of the type annotation.
+ pandas/_libs/tslibs/timedeltas.pyi:147:36: RUF036 [*] `None` not at the end of the type union.
- pandas/_libs/tslibs/timedeltas.pyi:147:36: RUF036 `None` not at the end of the type annotation.
+ pandas/_libs/tslibs/timestamps.pyi:31:25: RUF036 [*] `None` not at the end of the type union.
- pandas/_libs/tslibs/timestamps.pyi:31:41: RUF036 `None` not at the end of the type annotation.
+ pandas/core/arrays/datetimelike.py:1075:45: RUF036 [*] `None` not at the end of the type union.
- pandas/core/arrays/datetimelike.py:1075:45: RUF036 `None` not at the end of the type annotation.
+ pandas/core/dtypes/cast.py:186:29: RUF036 [*] `None` not at the end of the type union.
- pandas/core/dtypes/cast.py:186:38: RUF036 `None` not at the end of the type annotation.
... 46 additional changes omitted for project

python/typeshed (+143 -143 violations, +0 -0 fixes)

ruff check --no-cache --exit-zero --no-fix --output-format concise --preview --select E,F,FA,I,PYI,RUF,UP,W

+ stdlib/_interpreters.pyi:30:6: RUF036 [*] `None` not at the end of the type union.
- stdlib/_interpreters.pyi:30:6: RUF036 `None` not at the end of the type annotation.
+ stdlib/_ssl.pyi:82:58: RUF036 [*] `None` not at the end of the type union.
- stdlib/_ssl.pyi:82:58: RUF036 `None` not at the end of the type annotation.
+ stdlib/ast.pyi:1096:51: RUF036 [*] `None` not at the end of the type union.
- stdlib/ast.pyi:1096:96: RUF036 `None` not at the end of the type annotation.
+ stdlib/ast.pyi:1099:51: RUF036 [*] `None` not at the end of the type union.
- stdlib/ast.pyi:1099:96: RUF036 `None` not at the end of the type annotation.
+ stdlib/ast.pyi:1754:26: RUF036 [*] `None` not at the end of the type union.
- stdlib/ast.pyi:1754:26: RUF036 `None` not at the end of the type annotation.
+ stdlib/ast.pyi:1764:26: RUF036 [*] `None` not at the end of the type union.
- stdlib/ast.pyi:1764:26: RUF036 `None` not at the end of the type annotation.
+ stdlib/ast.pyi:1774:26: RUF036 [*] `None` not at the end of the type union.
- stdlib/ast.pyi:1774:26: RUF036 `None` not at the end of the type annotation.
+ stdlib/ast.pyi:1784:26: RUF036 [*] `None` not at the end of the type union.
- stdlib/ast.pyi:1784:26: RUF036 `None` not at the end of the type annotation.
+ stdlib/ast.pyi:1794:26: RUF036 [*] `None` not at the end of the type union.
- stdlib/ast.pyi:1794:26: RUF036 `None` not at the end of the type annotation.
+ stdlib/ast.pyi:1803:26: RUF036 [*] `None` not at the end of the type union.
... 267 additional changes omitted for project

... Truncated remaining completed project reports due to GitHub comment length restrictions

Changes by rule (1 rules affected)

code	total	+ violation	- violation	+ fix	- fix
RUF036	734	367	367	0	0

ntBre · 2026-02-23T20:04:12Z

Thanks @anishgirianish for working on this! I haven't looked at the diff yet, so apologies if you've addressed all of these, but I was hoping you could check whether or not you had resolved my comment on a previous version of this PR? See #18964 (review) and the comments it links to on an even earlier version. I think that's a good summary of the missing pieces from the earlier iterations and would help me get started reviewing this PR.

anishgirianish · 2026-02-23T20:11:20Z

Thanks @anishgirianish for working on this! I haven't looked at the diff yet, so apologies if you've addressed all of these, but I was hoping you could check whether or not you had resolved my comment on a previous version of this PR? See #18964 (review) and the comments it links to on an even earlier version. I think that's a good summary of the missing pieces from the earlier iterations and would help me get started reviewing this PR.

Sure will do thanks

anishgirianish added 2 commits January 23, 2026 21:54

[] Add fix for none-not-at-end-of-union ()

0ac1712

clean ups

6fc3dcb

anishgirianish changed the title ~~[ruff] Add fix for none-not-at-end-of-union (RUF036)~~ [ruff] Add fix for none-not-at-end-of-union (RUF036) Jan 24, 2026

anishgirianish mentioned this pull request Jan 24, 2026

Feature request: Autofix for none-not-at-end-of-union (RUF036) #15136

Open

amyreese requested a review from ntBre February 13, 2026 23:07

amyreese reviewed Feb 13, 2026

View reviewed changes

[RUF036] refactor

20730d9

anishgirianish requested a review from amyreese February 14, 2026 07:33

anishgirianish added 3 commits February 24, 2026 18:00

[ruff] addressed review comments and refactor

d0235ca

Merge remote-tracking branch 'upstream/main' into feat/ruf036-autofix

73a390c

[ruff] clean ups

7cec1d7

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[ruff] Add fix for `none-not-at-end-of-union` (RUF036) #22829

[ruff] Add fix for `none-not-at-end-of-union` (RUF036) #22829
anishgirianish wants to merge 6 commits intoastral-sh:mainfrom
anishgirianish:feat/ruf036-autofix

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anishgirianish commented Jan 24, 2026

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ruff-ecosystem results

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