[red-knot] Refresh diagnostics when changing related files

[MichaReiser]

Summary

Given:

main.py:

from foo import Foo

foo.py

class Fo: ...

Red Knot reports an unresolved import diagnostic in main.py because foo doesn't export Foo.
Renaming the class Fo in foo.py to Foo should refresh the diagnsotics in main.py.

It turns out, that this is a fairly easy change. All that was necessary is to set inter_file_dependencies in the server registration options to true.

We'll need a different solution for publish diagnostics but Red Knot doesn't yet support publish diagnostics (astral-sh/ty#79)

Test Plan

Screen.Recording.2025-04-11.at.14.46.47.mov

[github-actions]

mypy_primer results

No ecosystem changes detected ✅

[dhruvmanila]

Nice!

[dhruvmanila]

We'll need a different solution for publish diagnostics but Red Knot doesn't yet support publish diagnostics

Yeah, I think we might need to keep track of the diagnostic dependencies ourselves in that case and if any of the dependent file changes, we'll need to refresh the diagnostics for the parent files. This might also become useful and required for caching diagnostics on the server side.

[MichaReiser]

Yeah, I think we might need to keep track of the diagnostic dependencies ourselves in that case and if any of the dependent file changes, we'll need to refresh the diagnostics for the parent files. This might also become useful and required for caching diagnostics on the server side.

Yeah, I'm not sure how that would work because we have no way of asking: What files does file X depend on. Only including its direct dependencies isn't good enough. We might have to publish all diagnostics eagerly. I wanted to look into how r-a does that.