resolver_context

Sometimes you can’t (or don’t want to) pass a diwire.Container through every layer of your app. For those cases, diwire provides diwire.resolver_context: a shared diwire.ResolverContext instance.

What it is (and isn’t)

• Resolver binding is task/thread-safe and uses contextvars.

• resolve / aresolve / enter_scope use the currently bound resolver first, and fall back to the latest container configured for this ResolverContext.

• inject can use one of three resolver sources at call time: explicit diwire_resolver, bound resolver from resolver_context, or fallback container compile when the fallback container is configured with use_resolver_context=True.

• Fallback container policy is last container wins per ResolverContext instance.

Basic usage

1. Build/configure a container (this automatically registers fallback for resolver_context calls).

2. Use @resolver_context.inject for function wrappers.

3. Optionally bind resolver context explicitly when you need call-local precedence:

   from diwire import Container, resolver_context
   
   
   class MyDependency:
       ...
   
   
   container = Container()
   container.add(MyDependency)
   
   with container.compile():
       value = resolver_context.resolve(MyDependency)
   
   assert isinstance(value, MyDependency)
   

Runnable example: ResolverContext.

Testing note

Prefer one of:

• pass diwire_resolver=container.compile() explicitly in wrappers, or

• create an app-owned ResolverContext() per test for isolation.