<!--
Thank you for contributing to Ruff! To help us out with reviewing,
please consider the following:
- Does this pull request include a summary of the change? (See below.)
- Does this pull request include a descriptive title?
- Does this pull request include references to any relevant issues?
-->
## Summary
Fixes#8334.
`Display` has been implemented for `ruff_workspace::Settings`, which
gives a much nicer and more readable output to `--show-settings`.
Internally, a `display_settings` utility macro has been implemented to
reduce the boilerplate of the display code.
### Work to be done
- [x] A lot of formatting for `Vec<_>` and `HashSet<_>` types have been
stubbed out, using `Debug` as a fallback. There should be a way to add
generic formatting support for these types as a modifier in
`display_settings`.
- [x] Several complex types were also stubbed out and need proper
`Display` implementations rather than falling back on `Debug`.
- [x] An open question needs to be answered: how important is it that
the output be valid TOML? Some types in settings, such as a hash-map
from a glob pattern to a multi-variant enum, will be hard to rework into
valid _and_ readable TOML.
- [x] Tests need to be implemented.
## Test Plan
Tests consist of a snapshot test for the default `--show-settings`
output and a doctest for `display_settings!`.
## Summary
This PR renames the `tab-size` configuration option to `indent-width` to
express that the formatter uses the option to determine the indentation
width AND as tab width.
I first preferred naming the option `tab-width` but then decided to go
with `indent-width` because:
* It aligns with the `indent-style` option
* It would allow us to write a lint rule that asserts that each
indentation uses `indent-width` spaces.
Closes#7643
## Test Plan
Added integration test
## Summary
Restores functionality of #7875 but in the correct place. Closes#7877.
~~I couldn't figure out how to get cargo fmt to work, so hopefully
that's run in CI.~~ Nevermind, figured it out.
## Test Plan
Can see output of json.
## Summary
This PR resolves an issue raised in
https://github.com/astral-sh/ruff/discussions/7810, whereby we don't fix
an f-string that exceeds the line length _even if_ the resultant code is
_shorter_ than the current code.
As part of this change, I've also refactored and extracted some common
logic we use around "ensuring a fix isn't breaking the line length
rules".
## Test Plan
`cargo test`
