## Summary
This PR moves `Diagnostic`, `DiagnosticKind`, and `Fix` into their own crate, which will enable us to further split up Ruff, since sub-linter crates (which need to implement functions that return `Diagnostic`) can now depend on `ruff_diagnostics` rather than Ruff.
This PR productionizes @MichaReiser's suggestion in https://github.com/charliermarsh/ruff/issues/1820#issuecomment-1440204423, by creating a separate crate for the `ast` module (`rust_python_ast`). This will enable us to further split up the `ruff` crate, as we'll be able to create (e.g.) separate sub-linter crates that have access to these common AST utilities.
This was mostly a straightforward copy (with adjustments to module imports), as the few dependencies that _did_ require modifications were handled in #3366, #3367, and #3368.
In 28c9263722 I introduced automatic
linkification of option references in rule documentation,
which automatically converted the following:
## Options
* `namespace-packages`
to:
## Options
* [`namespace-packages`]
[`namespace-packages`]: ../../settings#namespace-packages
While the above is a correct CommonMark[1] link definition,
what I was missing was that we used mkdocs for our documentation
generation, which as it turns out uses a non-CommonMark-compliant
Markdown parser, namely Python-Markdown, which contrary to CommonMark
doesn't support link definitions containing code tags.
This commit fixes the broken links via a regex hack.
[1]: https://commonmark.org/
Rule::noqa_code previously return a single &'static str,
which was possible because we had one enum listing all
rule code prefixes. This commit series will however split up
the RuleCodePrefix enum into several enums ... so we'll end up
with two &'static str ... this commit wraps the return type
of Rule::noqa_code into a newtype so that we can easily change
it to return two &'static str in the 6th commit of this series.
Post this commit series several codes can be mapped to a single rule,
this commit therefore renames Rule::code to Rule::noqa_code,
which is the code that --add-noqa will add to ignore a rule.
Previously the rule documentation referenced configuration options
via full https:// URLs, which was bad for several reasons:
* changing the website would mean you'd have to change all URLs
* the links didn't work when building mkdocs locally
* the URLs showed up in the `ruff rule` output
* broken references weren't detected by our CI
This commit solves all of these problems by post-processing the
Markdown, recognizing sections such as:
## Options
* `flake8-tidy-imports.ban-relative-imports`
`cargo dev generate-all` will automatically linkify such references
and panic if the referenced option doesn't exist.
Note that the option can also be linked in the other Markdown sections
via e.g. [`flake8-tidy-imports.ban-relative-imports`] since
the post-processing code generates a CommonMark link definition.
Resolves#2766.
