**Summary** Prepare for the black preview style becoming the black
stable style at the end of the year.
This adds a new test file to compare stable and preview on some relevant
preview options in black, and makes `format_dev` understand the black
preview flag. I've added poetry as a project that uses preview.
I've implemented one specific deviation (collapsing of stub
implementation in non-stub files) which showed up in poetry for testing.
This also improves poetry compatibility from 0.99891 to 0.99919.
Fixes#7440
New compatibility stats:
| project | similarity index | total files | changed files |
|----------------|------------------:|------------------:|------------------:|
| cpython | 0.75803 | 1799 | 1647 |
| django | 0.99983 | 2772 | 35 |
| home-assistant | 0.99953 | 10596 | 189 |
| poetry | 0.99919 | 317 | 12 |
| transformers | 0.99963 | 2657 | 332 |
| twine | 1.00000 | 33 | 0 |
| typeshed | 0.99978 | 3669 | 20 |
| warehouse | 0.99969 | 654 | 15 |
| zulip | 0.99970 | 1459 | 22 |
## Summary
This PR fixes the bug where the formatter would panic if a class/function with
decorators had a suppression comment.
The fix is to use to correct start location to find the `async`/`def`/`class`
keyword when decorators are present which is the end of the last
decorator.
## Test Plan
Add test cases for the fix and update the snapshots.
## Summary
The motivation here is that this enables us to implement `Ranged` in
crates that don't depend on `ruff_python_ast`.
Largely a mechanical refactor with a lot of regex, Clippy help, and
manual fixups.
## Test Plan
`cargo test`
konsti
Charlie Marsh
Dhruv Manilawala
Micha Reiser
Tom Kuson