is it possible to extend dependency inference for a custom t Pants #plugins

is it possible to “extend” dependency inference fo...

sparse-lifeguard-95737

07/05/2022, 2:25 PM

is it possible to “extend” dependency inference for a custom target type? i.e. I’m considering making a custom target for Django

apps.py

files, to replicate the dependency rules that Django uses for pulling in models/migrations/templates etc. Our

apps.py

files are mostly lightweight, but a few import some 3rd-party libraries. wondering if I could implement a dependency-inference rule for

MyCustomDjangoAppsTarget

, and within the rule do something like

cast(PythonSourceTarget, my_custom_target)

, use that to run the “default” dependency inference for python code, then tack on the extra django-specific dependencies

fast-nail-55400

07/05/2022, 2:26 PM

Yes although the exact pattern to do so focuses on the subclassing field(s) in the target and not the original target per se.

🤔 1

fast-nail-55400

07/05/2022, 2:29 PM

1. Subclass either the source field (if you are using

InferDependenciesRequest

) or the

Dependencies

field (if using

InjectDependenciesRequest

) 2. Have your custom target use the same fields as the original target except use your subclassed field instead of the original field. The “target API” intentionally knows about the subclass relationship. Any request in other code for the base class will pick up your subclassed field. 3. Implement your dependency inference rule and use your subclass as what to inject/infer for.

sparse-lifeguard-95737

07/05/2022, 2:31 PM

aha nice, ty!

fast-nail-55400

07/05/2022, 2:31 PM

You can find examples in the Python rules. E.g.,

PythonTestsDependenciesField

fast-nail-55400

07/05/2022, 2:32 PM

(which uses this pattern to override a transitive excludes behavior)

8 Views

Open in Slack

Previous Next