#139 Auto context for Context Resources

[alexanderlazarev0]

Implements #139.

[alexanderlazarev0]

Point of discussion:

Currently, this feature is implemented in such a way that a new context is created whenever we attempt to resolve a resource. However, we do not prevent the initialization of the resources' context. For example:

r = providers.ContextResource(some_func, auto_context=True)
with r.sync_context(): # actually makes a new context which will never be used.
    ...

Possible temporary solution:

In the above example, the user is making a logic mistake, however, imagine a scenario where you have a container with many providers:

class Container(BaseContainer):
    # many more providers here
    r = providers.ContextResource(some_func, auto_context=True)

with Container.sync_context(): # actually makes a new context for `r` which will never be used.
    ...

Here, the user also will initialize a context for r for no reason.

So what can be done is: when one enters Container.sync_context(), one can check if the provider is a ContextResource and has auto_context==True and only then initialize a new context.

Possible long-term solution:

It can be argued that we want to know if a user is making an explicit context initialization as in the first example, or if this is done by an internal that-depends call (as in example 2). Then we would raise an error for the user, and for internal calls ignore the instruction. This would require rewriting the current interface to have both public and private calls.

[alexanderlazarev0]

@lesnik512 Yes my bad I need to rework this.