ruff/crates/ruff_python_formatter
Micha Reiser 1559c73fcd
Fix fstring formatting removing overlong implicit concatenated string in expression part (#14811)
## Summary

Fixes https://github.com/astral-sh/ruff/issues/14778


The formatter incorrectly removed the inner implicitly concatenated
string for following single-line f-string:

```py
f"{'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' 'a' if True else ""}"

# formatted
f"{ if True else ''}"
```

This happened because I changed the `RemoveSoftlinesBuffer` in
https://github.com/astral-sh/ruff/pull/14489 to remove any content
wrapped in `if_group_breaks`. After all, it emulates an *all flat*
layout. This works fine when `if_group_breaks` is only used to **add**
content if the gorup breaks. It doesn't work if the same content is
rendered differently depending on if the group fits using
`if_group_breaks` and `if_groups_fits` because the enclosing `group`
might still *break* if the entire content exceeds the line-length limit.

This PR fixes this by unwrapping any `if_group_fits` content by removing
the `if_group_fits` start and end tags.


## Test Plan

added test
2024-12-06 13:01:04 +01:00
..
resources/test/fixtures Fix fstring formatting removing overlong implicit concatenated string in expression part (#14811) 2024-12-06 13:01:04 +01:00
src Upgrade Rust toolchain to 1.83 (#14677) 2024-11-29 12:05:05 +00:00
tests Fix fstring formatting removing overlong implicit concatenated string in expression part (#14811) 2024-12-06 13:01:04 +01:00
Cargo.toml Bump MSRV to Rust 1.80 (#13826) 2024-10-20 10:55:36 +02:00
CONTRIBUTING.md Update pre-commit dependencies (#14719) 2024-12-02 06:02:56 +00:00
generate.py Normalize implicit concatenated f-string quotes per part (#13539) 2024-10-08 09:59:17 +00:00
orphan_rules_in_the_formatter.svg Generate FormatRule definitions (#4724) 2023-06-01 08:38:53 +02:00
README.md Move deviations from formatter README to documentation (#10444) 2024-03-18 08:22:28 +00:00

Ruff Formatter

The Ruff formatter is an extremely fast Python code formatter that ships as part of the ruff CLI.

Goals

The formatter is designed to be a drop-in replacement for Black, but with an excessive focus on performance and direct integration with Ruff.

Specifically, the formatter is intended to emit near-identical output when run over Black-formatted code. When run over extensive Black-formatted projects like Django and Zulip, > 99.9% of lines are formatted identically. When migrating an existing project from Black to Ruff, you should expect to see a few differences on the margins, but the vast majority of your code should be unchanged.

If you identify deviations in your project, spot-check them against the intentional deviations enumerated below, as well as the unintentional deviations filed in the issue tracker. If you've identified a new deviation, please file an issue.

When run over non-Black-formatted code, the formatter makes some different decisions than Black, and so more deviations should be expected, especially around the treatment of end-of-line comments. For details, see Black compatibility.

Getting started

The Ruff formatter is available as of Ruff v0.1.2. Head to The Ruff Formatter for usage instructions and a comparison to Black.