About factory provider design, why can not direct set as singleton.

[llucasspot]

Describe the bug / design arrangement
I am reopening this topic : #14

Expected behavior
that factory service can be singleton as well if needed

[llucasspot]

Hi, I see you said years ago :

"This is by design, singleton/transient doesn't really make much sense for a factory. Since with a factory, we want the factory method to run each time we resolve a token."

=> i dont realy understand your words here, why it doesn't really make much sense ?
Sometimes we want to make singleton services where his implementation need a other service from the container

exemple with cart service :

registerByValue(CartApiServiceInterface, new LocalStorageCartApiService());
 registerByFactory(CartService, (container) => {
    return new CartService(container.getInstance(CartApiServiceInterface));
  });

with CartService the fonctional service and CartApiServiceInterface the technical adaptor that can be change if we want to have a api by local storage or web api storage bh exemple

[llucasspot]

that is sad to be force to use instanceCachingFactory to overcome this issue

useFactory: instanceCachingFactory((container) => {
                return useFactory(container);
            }),

this sould be a "buildin" feature like the others with the options LifeCycle

Cordially

[alaboudi]

I also want to reopen this. I think we need factories to be singleton.

I have the following situations.

interface A {}
class ImpA implements A {}

abstract class B {
 constructor(a: A)
}

class ExtendedB extends B {}

such that A and B will be represented by specific singletons in the context of my application.

So I was hoping to do the following

container.registerSingleton("A", ImpA);
container.register<B>("B", {
  lifecycle: Lifecycle.Singleton,
  useFactory: (c) => new ExtendedB(c.resolve("A"))
})

Does this not make sense as a use case? But this unfortunately is not possible in this library. Seems like a legit use case no?