Inject context and some builtin InjectionKeys

[mdbetancourt]

i think that should exists some builtin keys like ContextKey
const ContextKey: InjectionKey<SetupContext> = Symbol('tt')
so we can get context (store, router) through injection like

import { InjectionKeys } from 'vue'

function useProduct() {
  const { root: { $store } } = inject(InjectionKeys.Context)
  // do something with $store
}

this can make more modular "use" functions

[jods4]

FWIW vue-router solved this by exposing some useRoute and useRouter functions, so you can get the router like so:

import { useRouter } from 'vue-router'

function useStuff() {
  const $router = useRouter()
}

Internally it's just:

import { inject } from 'vue'

export function useRouter() {
  return inject('$ref')
}

It's easy to use and a bonus point is that it's strongly typed if you use TS.
The inject('$router') way is also strongly typed but only if you import 'vue-router', which you'd probably not do... so it's slightly inferior.