fix(runtime-core): fix inject with currentApp

[linzhe141]

const app = createApp({
  setup() {
    const childApp = createApp({
      setup() { },
    })
    expect(childApp.runWithContext(() => inject('bar'))).toBe('bar')
    return () => h('div')
  },
})

app.provide('bar', 'bar')

What is expected?
expect(childApp.runWithContext(() => inject('bar'))).toBe('bar')
What is actually happening?

[github-actions]

Size Report

Bundles

File	Size	Gzip	Brotli
runtime-dom.global.prod.js	98.8 kB (+32 B)	37.4 kB (+12 B)	33.7 kB (+2 B)
vue.global.prod.js	156 kB (+32 B)	57.2 kB (+11 B)	50.8 kB (-18 B)

Usages

Name	Size	Gzip	Brotli
createApp	54.2 kB (+32 B)	21 kB (+15 B)	19.1 kB (+18 B)
createSSRApp	58.1 kB (+32 B)	22.6 kB (+15 B)	20.6 kB (-4 B)
defineCustomElement	58.8 kB (+32 B)	22.5 kB (+11 B)	20.5 kB (+6 B)
overall	67.8 kB (+32 B)	26 kB (+14 B)	23.7 kB (+9 B)

[Gianthard-cyh]

Good job! But I think this won't fix the issue since it's not something really wrong with Vue itself. Please take a look at my comment here for more details: link.

[edison1105]

should move this code above const provides = instance

[edison1105]

@Gianthard-cyh
this PR did not fix #11602.
It will fix another scene, but I don't know if this is needed.

Misunderstood.

[Gianthard-cyh]

@Gianthard-cyh this PR did not fix #11602. It will fix another scene, but I don't know if this is needed.

Yes, I think this PR is actually doing this: fall back to the component's provides if there is a currentApp but key is not found in its provides.

Also, this will affect the behavior of pinia when injecting a property provided by a component. The setup() function of pinia store is wrapped in runWithContext(), so currentApp is available. If the key is not found, it will fallback to the component's provides. If it is expected to receive an undefined (like we have discussed in #11602), this PR will break the behavior.

I think this needs to be further discussed: should inject() fall back to the component instance's provides when it is called in runWithContext() and key is not found? What is expected?

[linzhe141]

@Gianthard-cyh Thank you for your review, but I don’t know how to cancel the associated issue.

[yyx990803]

It should not fallback because that would make the behavior of Pinia stores indeterministic.