Separate handler state types

[danielgrigg]

Hello, new axum user and loving it! I had a question on how to approach architecting routes and stateful dependencies.

I'm trying to create some routes such that each handler injects only its required dependencies, eg a create_user handler might only inject a UserRepository but the whole app may consist of a hundred such repositories and bundling them all into a shared state isn't ideal.
I saw there's a with_state method and the docs and example suggest that independent handlers with differing state types can be merged together but I don't see it'd compile given the type constraint that the (using example types) InnerState be convertible into the OuterState? Am I trying to use it correctly? Or should I use another method?
For now I'm using a single state type but I can quickly see it becoming a god class coupled to everything.

[davidpdrsn]

but I don't see it'd compile given the type constraint that the (using example types) InnerState be convertible into the OuterState? Am I trying to use it correctly? Or should I use another method?

You're probably missing #[derive(FromRef)] on your overall state type.

If you really do want different states you can do this.