ruff/crates/ruff_python_formatter
Brent Westbrook 23c98849fc
Preserve quotes in generated f-strings (#15794)
## Summary

This is another follow-up to #15726 and #15778, extending the
quote-preserving behavior to f-strings and deleting the now-unused
`Generator::quote` field.

## Details
I also made one unrelated change to `rules/flynt/helpers.rs` to remove a
`to_string` call for making a `Box<str>` and tweaked some arguments to
some of the `Generator::unparse_f_string` methods to make the code
easier to follow, in my opinion. Happy to revert especially the latter
of these if needed.

Unfortunately this still does not fix the issue in #9660, which appears
to be more of an escaping issue than a quote-preservation issue. After
#15726, the result is now `a = f'# {"".join([])}' if 1 else ""` instead
of `a = f"# {''.join([])}" if 1 else ""` (single quotes on the outside
now), but we still don't have the desired behavior of double quotes
everywhere on Python 3.12+. I added a test for this but split it off
into another branch since it ended up being unaddressed here, but my
`dbg!` statements showed the correct preferred quotes going into
[`UnicodeEscape::with_preferred_quote`](https://github.com/astral-sh/ruff/blob/main/crates/ruff_python_literal/src/escape.rs#L54).

## Test Plan

Existing rule and `Generator` tests.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-01-29 13:28:22 -05:00
..
resources/test/fixtures Fix unstable f-string formatting for expressions containing a trailing comma (#15545) 2025-01-17 10:08:09 +01:00
src Remove customizable reference enum names (#15647) 2025-01-21 13:46:31 -05:00
tests Preserve quotes in generated f-strings (#15794) 2025-01-29 13:28:22 -05:00
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 Standardise ruff config (#15558) 2025-01-21 12:09:11 +01:00
orphan_rules_in_the_formatter.svg Generate FormatRule definitions (#4724) 2023-06-01 08:38:53 +02:00
README.md Add f-string formatting to the docs (#15367) 2025-01-09 10:20:06 +01:00

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 Style Guide.

Getting started

Head to The Ruff Formatter for usage instructions and a comparison to Black.