Brent Westbrook c8589d0eb1 Move diagnostic format dispatch into Ruff and ty (#29647) ...

Summary
--

This addresses the suggestion from [#29635]. `DisplayDiagnosticConfig`
previously determined the
`DiagnosticFormat` for diagnostics coming from both Ruff and ty, which
meant that it had to have a
shared enum between the two, despite each program supporting a different
subset of the available
formats. This PR eliminates the shared `DiagnosticFormat` and dispatch
through `DisplayDiagnostics`,
leaving Ruff and ty to construct `Renderer`s directly and do their own
dispatch on the output
formats they actually support. This will be especially helpful in
#29635, where we want to provide
slightly different arguments to each new `SarifRenderer`.

The `Renderer` trait itself isn't strictly necessary, but it made the
calls on the Ruff side a lot
neater since the trait provides a default `write` method based on the
required `render` method.
Codex also threw in a default `display` method that helps in a couple of
places too.

Test Plan
--

Existing tests

[#29635]:
https://github.com/astral-sh/ruff/pull/29635#discussion_r4352505588

2026-10-23 09:38:24 -04:00

..

snapshots

Update default and latest Python versions for 3.15 (#28792)

2026-10-09 12:26:57 -04:00

fixtures.rs

Move diagnostic format dispatch into Ruff and ty (#29647)

2026-10-23 09:38:24 -04:00

normalizer.rs

[ty] Reduce retained AST memory by shrinking expressions (#28335)

2026-09-10 15:39:14 -04:00