Fix #4653 If guard explosion in case statement by rxjacob · Pull Request #4884 · psf/black

rxjacob · 2025-12-05T23:08:57Z

Description

Black is exploding the if guard in case patterns which have trailing commas in them, even if the guard expression fits in one line. The trailing comma logic should apply only to the case pattern, not the if guard.

Checklist - did you ...

Implement any code style changes under the --preview style, following the
stability policy?
Add an entry in CHANGES.md if necessary?
Add / update tests if necessary?
Add new / update outdated documentation?

cobaltt7 · 2025-12-06T02:40:24Z

This code doesn't build.

github-actions · 2025-12-07T21:35:57Z

diff-shades results comparing this PR (56abf99) to main (ff094ac):

--preview style (View full diff):

╭─────────────────────── Summary ────────────────────────╮ │ 1 projects & 1 files changed / 4 changes [+1/-3] │ │ │ │ ... out of 2 885 468 lines, 13 632 files & 22 projects │ ╰────────────────────────────────────────────────────────╯

Differences found.

--stable style: no changes

What is this? | Workflow run | diff-shades documentation

rxjacob · 2025-12-07T21:46:29Z

This code doesn't build.

Updated the PR with the fix.

cobaltt7 · 2026-01-01T06:30:33Z

Thanks! Can you gate this change to the preview style, since it changes previous formatting?

for more information, see https://pre-commit.ci

rxjacob · 2026-01-03T21:42:39Z

Thanks! Can you gate this change to the preview style, since it changes previous formatting?

Done.

cobaltt7 · 2026-01-04T02:30:06Z

Sorry, please add and check for a specific preview style, instead of the entire preview style as a whole. Here's a recent example: https://github.com/psf/black/pull/4865/changes. To test it, add the line # flags: --preview to the top of the test file.

Also, it looks like there's some unintentional formatting changes in one of the other tests

for more information, see https://pre-commit.ci

src/black/mode.py

for more information, see https://pre-commit.ci

@cobaltt7

* Updated changelog to resolve conflict * Gating change to preview style, fixed merge conflict * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * removed extra entries * added test case * Fixed preview style and unintentional formatting changes * removed extra line in mode.py * added unstable change * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * Apply suggestion from @cobaltt7 * Move docs to preview style * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * Reorder enum values in black.schema.json --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com> Co-authored-by: cobalt <61329810+cobaltt7@users.noreply.github.com>

This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [black](https://github.com/psf/black) ([changelog](https://github.com/psf/black/blob/main/CHANGES.md)) | `<26.1.1,>=26.1.0` → `<26.3.1,>=26.3.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/black/26.3.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/black/26.1.0/26.3.0?slim=true) | --- ### Release Notes <details> <summary>psf/black (black)</summary> ### [`v26.3.0`](https://github.com/psf/black/blob/HEAD/CHANGES.md#2630) [Compare Source](psf/black@26.1.0...26.3.0) ##### Stable style - Don't double-decode input, causing non-UTF-8 files to be corrupted ([#4964](psf/black#4964)) - Fix crash on standalone comment in lambda default arguments ([#4993](psf/black#4993)) - Preserve parentheses when `# type: ignore` comments would be merged with other comments on the same line, preventing AST equivalence failures ([#4888](psf/black#4888)) ##### Preview style - Fix bug where `if` guards in `case` blocks were incorrectly split when the pattern had a trailing comma ([#4884](psf/black#4884)) - Fix `string_processing` crashing on unassigned long string literals with trailing commas (one-item tuples) ([#4929](psf/black#4929)) - Simplify implementation of the power operator "hugging" logic ([#4918](psf/black#4918)) ##### Packaging - Fix shutdown errors in PyInstaller builds on macOS by disabling multiprocessing in frozen environments ([#4930](psf/black#4930)) ##### Performance - Introduce winloop for windows as an alternative to uvloop ([#4996](psf/black#4996)) - Remove deprecated function `uvloop.install()` in favor of `uvloop.new_event_loop()` ([#4996](psf/black#4996)) - Rename `maybe_install_uvloop` function to `maybe_use_uvloop` to simplify loop installation and creation of either a uvloop/winloop evenloop or default eventloop ([#4996](psf/black#4996)) ##### Output - Emit a clear warning when the target Python version is newer than the running Python version, since AST safety checks cannot parse newer syntax. Also replace the misleading "INTERNAL ERROR" message with an actionable error explaining the version mismatch ([#4983](psf/black#4983)) ##### *Blackd* - Introduce winloop to be used when windows in use which enables blackd to run faster on windows when winloop is installed. ([#4996](psf/black#4996)) ##### Integrations - Remove unused gallery script ([#5030](psf/black#5030)) - Harden parsing of `black` requirements in the GitHub Action when `use_pyproject` is enabled so that only version specifiers are accepted and direct references such as `black @ https://...` are rejected. Users should upgrade to the latest version of the action as soon as possible. This update is received automatically when using `psf/black@stable`, and is independent of the version of Black installed by the action. ([#5031](psf/black#5031)) ##### Documentation - Expand preview style documentation with detailed examples for `wrap_comprehension_in`, `simplify_power_operator_hugging`, and `wrap_long_dict_values_in_parens` features ([#4987](psf/black#4987)) - Add detailed documentation for formatting Jupyter Notebooks ([#5009](psf/black#5009)) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/repos/webexmemebot/pulls/571 Co-authored-by: renovate[bot] <renovate-bot@git.tainton.uk> Co-committed-by: renovate[bot] <renovate-bot@git.tainton.uk>

This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [black](https://github.com/psf/black) ([changelog](https://github.com/psf/black/blob/main/CHANGES.md)) | `<26.1.1,>=26.1.0` → `<26.3.1,>=26.3.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/black/26.3.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/black/26.1.0/26.3.0?slim=true) | --- ### Release Notes <details> <summary>psf/black (black)</summary> ### [`v26.3.0`](https://github.com/psf/black/blob/HEAD/CHANGES.md#2630) [Compare Source](psf/black@26.1.0...26.3.0) ##### Stable style - Don't double-decode input, causing non-UTF-8 files to be corrupted ([#4964](psf/black#4964)) - Fix crash on standalone comment in lambda default arguments ([#4993](psf/black#4993)) - Preserve parentheses when `# type: ignore` comments would be merged with other comments on the same line, preventing AST equivalence failures ([#4888](psf/black#4888)) ##### Preview style - Fix bug where `if` guards in `case` blocks were incorrectly split when the pattern had a trailing comma ([#4884](psf/black#4884)) - Fix `string_processing` crashing on unassigned long string literals with trailing commas (one-item tuples) ([#4929](psf/black#4929)) - Simplify implementation of the power operator "hugging" logic ([#4918](psf/black#4918)) ##### Packaging - Fix shutdown errors in PyInstaller builds on macOS by disabling multiprocessing in frozen environments ([#4930](psf/black#4930)) ##### Performance - Introduce winloop for windows as an alternative to uvloop ([#4996](psf/black#4996)) - Remove deprecated function `uvloop.install()` in favor of `uvloop.new_event_loop()` ([#4996](psf/black#4996)) - Rename `maybe_install_uvloop` function to `maybe_use_uvloop` to simplify loop installation and creation of either a uvloop/winloop evenloop or default eventloop ([#4996](psf/black#4996)) ##### Output - Emit a clear warning when the target Python version is newer than the running Python version, since AST safety checks cannot parse newer syntax. Also replace the misleading "INTERNAL ERROR" message with an actionable error explaining the version mismatch ([#4983](psf/black#4983)) ##### *Blackd* - Introduce winloop to be used when windows in use which enables blackd to run faster on windows when winloop is installed. ([#4996](psf/black#4996)) ##### Integrations - Remove unused gallery script ([#5030](psf/black#5030)) - Harden parsing of `black` requirements in the GitHub Action when `use_pyproject` is enabled so that only version specifiers are accepted and direct references such as `black @ https://...` are rejected. Users should upgrade to the latest version of the action as soon as possible. This update is received automatically when using `psf/black@stable`, and is independent of the version of Black installed by the action. ([#5031](psf/black#5031)) ##### Documentation - Expand preview style documentation with detailed examples for `wrap_comprehension_in`, `simplify_power_operator_hugging`, and `wrap_long_dict_values_in_parens` features ([#4987](psf/black#4987)) - Add detailed documentation for formatting Jupyter Notebooks ([#5009](psf/black#5009)) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/repos/pypilot/pulls/421 Reviewed-by: Luke Tainton <luke@tainton.uk> Co-authored-by: renovate[bot] <renovate-bot@git.tainton.uk> Co-committed-by: renovate[bot] <renovate-bot@git.tainton.uk>

This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [black](https://github.com/psf/black) ([changelog](https://github.com/psf/black/blob/main/CHANGES.md)) | `<26.1.1,>=26.1.0` → `<26.3.1,>=26.3.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/black/26.3.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/black/26.1.0/26.3.0?slim=true) | --- ### Release Notes <details> <summary>psf/black (black)</summary> ### [`v26.3.0`](https://github.com/psf/black/blob/HEAD/CHANGES.md#2630) [Compare Source](psf/black@26.1.0...26.3.0) ##### Stable style - Don't double-decode input, causing non-UTF-8 files to be corrupted ([#4964](psf/black#4964)) - Fix crash on standalone comment in lambda default arguments ([#4993](psf/black#4993)) - Preserve parentheses when `# type: ignore` comments would be merged with other comments on the same line, preventing AST equivalence failures ([#4888](psf/black#4888)) ##### Preview style - Fix bug where `if` guards in `case` blocks were incorrectly split when the pattern had a trailing comma ([#4884](psf/black#4884)) - Fix `string_processing` crashing on unassigned long string literals with trailing commas (one-item tuples) ([#4929](psf/black#4929)) - Simplify implementation of the power operator "hugging" logic ([#4918](psf/black#4918)) ##### Packaging - Fix shutdown errors in PyInstaller builds on macOS by disabling multiprocessing in frozen environments ([#4930](psf/black#4930)) ##### Performance - Introduce winloop for windows as an alternative to uvloop ([#4996](psf/black#4996)) - Remove deprecated function `uvloop.install()` in favor of `uvloop.new_event_loop()` ([#4996](psf/black#4996)) - Rename `maybe_install_uvloop` function to `maybe_use_uvloop` to simplify loop installation and creation of either a uvloop/winloop evenloop or default eventloop ([#4996](psf/black#4996)) ##### Output - Emit a clear warning when the target Python version is newer than the running Python version, since AST safety checks cannot parse newer syntax. Also replace the misleading "INTERNAL ERROR" message with an actionable error explaining the version mismatch ([#4983](psf/black#4983)) ##### *Blackd* - Introduce winloop to be used when windows in use which enables blackd to run faster on windows when winloop is installed. ([#4996](psf/black#4996)) ##### Integrations - Remove unused gallery script ([#5030](psf/black#5030)) - Harden parsing of `black` requirements in the GitHub Action when `use_pyproject` is enabled so that only version specifiers are accepted and direct references such as `black @ https://...` are rejected. Users should upgrade to the latest version of the action as soon as possible. This update is received automatically when using `psf/black@stable`, and is independent of the version of Black installed by the action. ([#5031](psf/black#5031)) ##### Documentation - Expand preview style documentation with detailed examples for `wrap_comprehension_in`, `simplify_power_operator_hugging`, and `wrap_long_dict_values_in_parens` features ([#4987](psf/black#4987)) - Add detailed documentation for formatting Jupyter Notebooks ([#5009](psf/black#5009)) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/luke/instant-msg-api/pulls/246 Reviewed-by: Luke Tainton <luke@tainton.uk> Co-authored-by: renovate[bot] <renovate-bot@git.tainton.uk> Co-committed-by: renovate[bot] <renovate-bot@git.tainton.uk>

This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [black](https://github.com/psf/black) ([changelog](https://github.com/psf/black/blob/main/CHANGES.md)) | `<26.1.1,>=26.1.0` → `<26.3.1,>=26.3.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/black/26.3.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/black/26.1.0/26.3.0?slim=true) | --- ### Release Notes <details> <summary>psf/black (black)</summary> ### [`v26.3.0`](https://github.com/psf/black/blob/HEAD/CHANGES.md#2630) [Compare Source](psf/black@26.1.0...26.3.0) ##### Stable style - Don't double-decode input, causing non-UTF-8 files to be corrupted ([#4964](psf/black#4964)) - Fix crash on standalone comment in lambda default arguments ([#4993](psf/black#4993)) - Preserve parentheses when `# type: ignore` comments would be merged with other comments on the same line, preventing AST equivalence failures ([#4888](psf/black#4888)) ##### Preview style - Fix bug where `if` guards in `case` blocks were incorrectly split when the pattern had a trailing comma ([#4884](psf/black#4884)) - Fix `string_processing` crashing on unassigned long string literals with trailing commas (one-item tuples) ([#4929](psf/black#4929)) - Simplify implementation of the power operator "hugging" logic ([#4918](psf/black#4918)) ##### Packaging - Fix shutdown errors in PyInstaller builds on macOS by disabling multiprocessing in frozen environments ([#4930](psf/black#4930)) ##### Performance - Introduce winloop for windows as an alternative to uvloop ([#4996](psf/black#4996)) - Remove deprecated function `uvloop.install()` in favor of `uvloop.new_event_loop()` ([#4996](psf/black#4996)) - Rename `maybe_install_uvloop` function to `maybe_use_uvloop` to simplify loop installation and creation of either a uvloop/winloop evenloop or default eventloop ([#4996](psf/black#4996)) ##### Output - Emit a clear warning when the target Python version is newer than the running Python version, since AST safety checks cannot parse newer syntax. Also replace the misleading "INTERNAL ERROR" message with an actionable error explaining the version mismatch ([#4983](psf/black#4983)) ##### *Blackd* - Introduce winloop to be used when windows in use which enables blackd to run faster on windows when winloop is installed. ([#4996](psf/black#4996)) ##### Integrations - Remove unused gallery script ([#5030](psf/black#5030)) - Harden parsing of `black` requirements in the GitHub Action when `use_pyproject` is enabled so that only version specifiers are accepted and direct references such as `black @ https://...` are rejected. Users should upgrade to the latest version of the action as soon as possible. This update is received automatically when using `psf/black@stable`, and is independent of the version of Black installed by the action. ([#5031](psf/black#5031)) ##### Documentation - Expand preview style documentation with detailed examples for `wrap_comprehension_in`, `simplify_power_operator_hugging`, and `wrap_long_dict_values_in_parens` features ([#4987](psf/black#4987)) - Add detailed documentation for formatting Jupyter Notebooks ([#5009](psf/black#5009)) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/repos/epage/pulls/208 Reviewed-by: Luke Tainton <luke@tainton.uk> Co-authored-by: renovate[bot] <renovate-bot@git.tainton.uk> Co-committed-by: renovate[bot] <renovate-bot@git.tainton.uk>

This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [black](https://github.com/psf/black) ([changelog](https://github.com/psf/black/blob/main/CHANGES.md)) | `<26.1.1,>=26.1.0` → `<26.3.1,>=26.3.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/black/26.3.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/black/26.1.0/26.3.0?slim=true) | --- ### Release Notes <details> <summary>psf/black (black)</summary> ### [`v26.3.0`](https://github.com/psf/black/blob/HEAD/CHANGES.md#2630) [Compare Source](psf/black@26.1.0...26.3.0) ##### Stable style - Don't double-decode input, causing non-UTF-8 files to be corrupted ([#4964](psf/black#4964)) - Fix crash on standalone comment in lambda default arguments ([#4993](psf/black#4993)) - Preserve parentheses when `# type: ignore` comments would be merged with other comments on the same line, preventing AST equivalence failures ([#4888](psf/black#4888)) ##### Preview style - Fix bug where `if` guards in `case` blocks were incorrectly split when the pattern had a trailing comma ([#4884](psf/black#4884)) - Fix `string_processing` crashing on unassigned long string literals with trailing commas (one-item tuples) ([#4929](psf/black#4929)) - Simplify implementation of the power operator "hugging" logic ([#4918](psf/black#4918)) ##### Packaging - Fix shutdown errors in PyInstaller builds on macOS by disabling multiprocessing in frozen environments ([#4930](psf/black#4930)) ##### Performance - Introduce winloop for windows as an alternative to uvloop ([#4996](psf/black#4996)) - Remove deprecated function `uvloop.install()` in favor of `uvloop.new_event_loop()` ([#4996](psf/black#4996)) - Rename `maybe_install_uvloop` function to `maybe_use_uvloop` to simplify loop installation and creation of either a uvloop/winloop evenloop or default eventloop ([#4996](psf/black#4996)) ##### Output - Emit a clear warning when the target Python version is newer than the running Python version, since AST safety checks cannot parse newer syntax. Also replace the misleading "INTERNAL ERROR" message with an actionable error explaining the version mismatch ([#4983](psf/black#4983)) ##### *Blackd* - Introduce winloop to be used when windows in use which enables blackd to run faster on windows when winloop is installed. ([#4996](psf/black#4996)) ##### Integrations - Remove unused gallery script ([#5030](psf/black#5030)) - Harden parsing of `black` requirements in the GitHub Action when `use_pyproject` is enabled so that only version specifiers are accepted and direct references such as `black @ https://...` are rejected. Users should upgrade to the latest version of the action as soon as possible. This update is received automatically when using `psf/black@stable`, and is independent of the version of Black installed by the action. ([#5031](psf/black#5031)) ##### Documentation - Expand preview style documentation with detailed examples for `wrap_comprehension_in`, `simplify_power_operator_hugging`, and `wrap_long_dict_values_in_parens` features ([#4987](psf/black#4987)) - Add detailed documentation for formatting Jupyter Notebooks ([#5009](psf/black#5009)) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/repos/PwnedPW/pulls/326 Reviewed-by: Luke Tainton <luke@tainton.uk> Co-authored-by: renovate[bot] <renovate-bot@git.tainton.uk> Co-committed-by: renovate[bot] <renovate-bot@git.tainton.uk>

This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [black](https://github.com/psf/black) ([changelog](https://github.com/psf/black/blob/main/CHANGES.md)) | `<26.1.1,>=26.1.0` → `<26.3.1,>=26.3.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/black/26.3.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/black/26.1.0/26.3.0?slim=true) | --- ### Release Notes <details> <summary>psf/black (black)</summary> ### [`v26.3.0`](https://github.com/psf/black/blob/HEAD/CHANGES.md#2630) [Compare Source](psf/black@26.1.0...26.3.0) ##### Stable style - Don't double-decode input, causing non-UTF-8 files to be corrupted ([#4964](psf/black#4964)) - Fix crash on standalone comment in lambda default arguments ([#4993](psf/black#4993)) - Preserve parentheses when `# type: ignore` comments would be merged with other comments on the same line, preventing AST equivalence failures ([#4888](psf/black#4888)) ##### Preview style - Fix bug where `if` guards in `case` blocks were incorrectly split when the pattern had a trailing comma ([#4884](psf/black#4884)) - Fix `string_processing` crashing on unassigned long string literals with trailing commas (one-item tuples) ([#4929](psf/black#4929)) - Simplify implementation of the power operator "hugging" logic ([#4918](psf/black#4918)) ##### Packaging - Fix shutdown errors in PyInstaller builds on macOS by disabling multiprocessing in frozen environments ([#4930](psf/black#4930)) ##### Performance - Introduce winloop for windows as an alternative to uvloop ([#4996](psf/black#4996)) - Remove deprecated function `uvloop.install()` in favor of `uvloop.new_event_loop()` ([#4996](psf/black#4996)) - Rename `maybe_install_uvloop` function to `maybe_use_uvloop` to simplify loop installation and creation of either a uvloop/winloop evenloop or default eventloop ([#4996](psf/black#4996)) ##### Output - Emit a clear warning when the target Python version is newer than the running Python version, since AST safety checks cannot parse newer syntax. Also replace the misleading "INTERNAL ERROR" message with an actionable error explaining the version mismatch ([#4983](psf/black#4983)) ##### *Blackd* - Introduce winloop to be used when windows in use which enables blackd to run faster on windows when winloop is installed. ([#4996](psf/black#4996)) ##### Integrations - Remove unused gallery script ([#5030](psf/black#5030)) - Harden parsing of `black` requirements in the GitHub Action when `use_pyproject` is enabled so that only version specifiers are accepted and direct references such as `black @ https://...` are rejected. Users should upgrade to the latest version of the action as soon as possible. This update is received automatically when using `psf/black@stable`, and is independent of the version of Black installed by the action. ([#5031](psf/black#5031)) ##### Documentation - Expand preview style documentation with detailed examples for `wrap_comprehension_in`, `simplify_power_operator_hugging`, and `wrap_long_dict_values_in_parens` features ([#4987](psf/black#4987)) - Add detailed documentation for formatting Jupyter Notebooks ([#5009](psf/black#5009)) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/repos/roboluke/pulls/431 Co-authored-by: renovate[bot] <renovate-bot@git.tainton.uk> Co-committed-by: renovate[bot] <renovate-bot@git.tainton.uk>

rxjacob force-pushed the rxjacob-patch-1-bug-4653 branch from 95d50bb to fa2598e Compare December 7, 2025 21:14

rxjacob changed the title ~~Rxjacob patch 1 bug 4653~~ Fixed #4653: If guard explosion in case statement Dec 8, 2025

rxjacob changed the title ~~Fixed #4653: If guard explosion in case statement~~ Fix #4653 If guard explosion in case statement Dec 8, 2025

cobaltt7 linked an issue Jan 1, 2026 that may be closed by this pull request

Trailing comma in case pattern causes if guard to explode #4653

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rxjacob added 2 commits January 3, 2026 13:33

Updated changelog to resolve conflict

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Gating change to preview style, fixed merge conflict

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rxjacob force-pushed the rxjacob-patch-1-bug-4653 branch from e975650 to 2080318 Compare January 3, 2026 21:40

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rxjacob added 2 commits January 3, 2026 13:50

removed extra entries

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added test case

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rxjacob and others added 5 commits January 4, 2026 22:46

Fixed preview style and unintentional formatting changes

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Merge branch 'main' into rxjacob-patch-1-bug-4653

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Merge branch 'main' into rxjacob-patch-1-bug-4653

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cobaltt7 merged commit 01c29bd into psf:main Mar 2, 2026
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Fix #4653 If guard explosion in case statement#4884

Fix #4653 If guard explosion in case statement#4884
cobaltt7 merged 15 commits intopsf:mainfrom
rxjacob:rxjacob-patch-1-bug-4653

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