How to use provide/inject and pinia stores together?

[dha-corey]

I'm exploring a design using provide/inject to more safely manage "almost-global" values in my application. At the core of it, I'm doing two things:

1. Calling provide in a Provider component that ensure the value is ready to use
2. Ensuring any functionality that relies on it is a child of the Provider, and using inject to receive said value

It's working beautifully, with one key exception: pinia stores (and a couple of similar home-brew composables that rely on detached EffectScopes). As soon as the Provider component unmounts, any components or composables that depend on its injected value will also unmount. But a Pinia store won't, so it'll hang on to a potentially stale or invalid value indefinitely.

For example, compare these two Pinia Playground examples. In both cases, I intentionally left out the LanguageProvider if the user chooses 'es' as their language.

LanguageProvider + useLanguage composable

Work exactly as expected. If you click en or fr, the greeting properly renders as "Hello" or "Bonjour". If you click es, an error is thrown. Regardless of order, you end up in a valid state

LanguageProvider + useLanguageStore pinia store

The first click works as expected, rendering a greeting for en and fr and throwing an error for es. However, subsequent clicks fail to change the language. Even though we're provide-ing a language of fr, our greeting still renders as "Hello".

My first thought was to implement a wrapper around inject() that would detect if it's called from a detached EffectScope and return undefined. But I also think inject should maybe already behave that way, and from other similar threads I've read I get the sense that poking around in getCurrentScope and getCurrentInstance internals is not recommended. So I'm curious if there's a better way to handle this, or if there's a reasonably stable way to prevent problematic calls to inject from a store. Or if I've completely misunderstood the intent of provide/inject to begin with, and should look elsewhere entirely.