If the other method has visibility of my foo property, then it can call it. Nothing is being "injected" anywhere. It's the moral equivalent of foo(req). It's statically dispatched
That is exactly dependency injection, the functions have to be embedded into a scope that has access to additional values because the framework doesn’t support passing them directly. The types are injected into the function by being embedded into another scope.
It’s not some kind of moral sin, but it is a kludge. The type system is now tied to the structure of your code, because scoping is now intrinsic to your types.
It’s not the end of the world, I’ve worked in similar systems, it just tends to have a heavy mental overhead at some point as you now have to keep scoping in mind as part of your types.
