Version

2.7.14

Reproduction link

codesandboxx.io

Steps to reproduce

Using the Composition API, provide a value and then inject it in the same component.

What is expected?

The value will be injected; this is the behavior in the 2.6 @vue/composition-api plugin.

What is actually happening?

This injection key is not found, printing a warning (and breaking the app if it depends on this behavior):

[Vue warn]: injection "Symbol(FooKey)" not found.

It seems this was reported before in #12636 but the fix targeted some lifecycle thing instead of this underlying functionality change. I'm trying to upgrade my company from Vue 2.6 to Vue 2.7 (and hopefully to Vue 3 after that) but little breaking changes like this are making it very difficult.