pants-ty-plugin

This plugin provides a Pants check backend using Ty - the new Python type checker from Astral (makers of uv and ruff).

Installation

This plugin was tested on Python 3.11 and Pants 2.31.0.dev3.

Add the following to your pants.toml file:

[GLOBAL]
plugins = [
    ...
    "robotpajamas.pants.ty",
]

...

backend_packages = [
    ...
    "experimental.ty",
]

Usage

This plugin is even more beta than Ty itself. It's largely just a copy/paste/rename of some existing Pants type checkers, so your mileage may vary.

pants check --only=ty src/foo/bar.py

The hard part of adding a new linter or formatter isn't usually the code itself, it's how to untangle the mess of configurations for the tool and weave them into various Pants-isms (e.g. configurations, interpreter constraints, partitions, environment variables, reasonable defaults, escape hatches, etc...).

FYI

Not without some amusement, I'm unable to type check the Ty plugin itself. The pants dependencies aren't picked up, and whether this relates to some of the namespace_packages bugs that Ty had earlier this year, or that I've missed a configuration - I'm not sure yet. MyPy works though.