It's actually quite simple: • Extend Pyright as an LSP server, with the main customization points just disabling incorrect features (like auto-import) • Have Pants generate

__builtins__.pyi

containing a definition for each target, CAOF, and object (Haven't done, the PoC just hand-wrote it for

python_sources

) • VS Code extension to wire it up

It's not perfect by any means. The biggest irk to me will be that builtins are registered definitions of

BUILD

, so it'll try and suggest

str

and

dict

.

Also, still need to figure out macros: • Tell Pyright about them for builtins sake I think if we came up with a special extension for them, linting/LSPing them wouldn't collide with Python

For macros definitions in

BUILD

files, I was thinking of just inlining them into the builtins generated pyi