4b0fa5f270
## Summary I spun this out from #21005 because I thought it might be helpful separately. It just renders a nice `Diagnostic` for syntax errors pointing to the source of the error. This seemed a bit more helpful to me than just the byte offset when working on #21005, and we had most of the code around after #20443 anyway. ## Test Plan This doesn't actually affect any passing tests, but here's an example of the additional output I got when I broke the spacing after the `in` token: ``` error[internal-error]: Expected 'in', found name --> /home/brent/astral/ruff/crates/ruff_python_formatter/resources/test/fixtures/black/cases/cantfit.py:50:79 | 48 | need_more_to_make_the_line_long_enough, 49 | ) 50 | del ([], name_1, name_2), [(), [], name_4, name_3], name_1[[name_2 for name_1 inname_0]] | ^^^^^^^^ 51 | del () | ``` I just appended this to the other existing output for now.
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.