Annotated Resolver

[ianjosephwilson]

I wrote my own mutant version of the wired dataclass dependency resolver for a project but then I started using Annotated and it seems to fit much better. This is related to #35 but I was not sure if I should continue there so I just started a new issue. I was hoping to integrate my changes here but I wasn't sure what would be the best way forward or if this approach fits with wired.

Features

• accepts a function OR class with dependencies marked within Annotated using Wired()
• allows attr, key or call_kwargs/call_args to further extract values from a service
• resolver can be used standalone
• works with dataclasses, inheritance and plain classes (needs further testing though)

Limitations

• Python 3.9+ AFAIK
• Converting Annotated to a normalized form might be more complicated.
• Might not integrate well with static type checkers

Why

• Annotated seems to work the same between function signatures and class properties which makes for a simpler API and implementation
• Avoids direct interaction with dataclass fields which makes for a simpler API because there is no need to proxy the behavior of field()
• The resolver can be used directly which could support pyramid view mappers.

AnnotatedDependencyExtractor in https://github.com/ianjosephwilson/wired_services/blob/main/src/wired_services/servicetools.py#L32 extracts the annotations into specifications of what to resolve

DependencyResolver in https://github.com/ianjosephwilson/wired_services/blob/main/src/wired_services/servicetools.py#L80

Injector actually injects the dependencies -- https://github.com/ianjosephwilson/wired_services/blob/main/src/wired_services/servicetools.py#L102

wired_service is the decorator that can be loaded with venusian to use the extractor, resolver and injector to construct the service.

[ianjosephwilson]

Prototype output looks like this:

$  hatch run python -- -m wired_services.testit
Hello there, the date and time is 2025-02-01T18:36:30.806211-08:00.
Hello again there, the date and time is 2025-02-01T18:36:30.806311-08:00.
Greetings to you! Hello Ian, the date and time is 2025-02-01T18:36:30.806448-08:00. Your lucky number is 175. And good day to you!