Clarifying questions about python.analysis.diagnosticsSource and python.analysis.pyrightVersion

[kkom]

I've very excited to see the python.analysis.diagnosticsSource and python.analysis.pyrightVersion options in Pylance! I hope that it will finally allow to generate diagnostic rules in the IDE, deterministically and consistently with CI configuration.

I have two clarifying questions:

(1) I read in the README.md that Pylance will combine its results with this other server.

Could you elaborate on what "results" mean here? Are we talking about reporting results of diagnostic rules, or something more?

As far as diagnostic rules go, I think it would be preferable to exclusively report the issues reported by the other server. This would increase consistency with type checking performed in CI. It will also be important in situations where a new version of Pyright doesn't just detect new issues, but e.g. stops detecting a false positive or renames rules (the latter affects pyright: ignore[ruleName] comments, which need to be renamed in lockstep with a Pyright update).

However, I can understand if this is impossible due to how the LSP is designed!

(2) Could you provide more information about what the pyright-langserver.js file is meant to look like?

I don't see any information about it online.

Thanks again for adding this functionality, it's really highly appreciated!

[kkom]

Actually, (1) is I think clear from the docs!

Allows running a different version of Pyright to generate diagnostics.

The "different" does suggest that we won't be combining diagnostics from 2 sources!

So it's just (2) that I would love to see some clarification about!

[rchiodo]

For 1), that diagnostics source was meant to support other language servers in the future. The 'combine' algorithm was going to be different for each. For Pyright it's not a combine, but rather a replacement. I'll update the readme to make that clearer.

For 2), the pyright-langserver.js file is the js bundle that Pyright ships for running a language server. If you install Pyright from PyPi (which this is intended to be for), it would be in this location: ~/.cache/pyright-python/1.1.397/node_modules/pyright/dist/pyright-langserver.js. I'll update the readme to make this clearer too.

[kkom]

That sounds great, thanks @rchiodo!

Might be worth looking at docs pages like https://github.com/microsoft/pylance-release/blob/71dcf9409c5ba65f1138069ac80ae9e2122d7867/USING_WITH_PYRIGHT.md as well