core/packages/dts-test/inject.test-d.ts

import { provide, inject, ref, Ref, InjectionKey } from 'vue'
import { expectType } from './utils'

provide('foo', 123)
provide(123, 123)

const key: InjectionKey<number> = Symbol()

provide(key, 1)
// @ts-expect-error
provide(key, 'foo')

expectType<number | undefined>(inject(key))
expectType<number>(inject(key, 1))
expectType<number>(inject(key, () => 1, true /* treatDefaultAsFactory */))

expectType<() => number>(inject('foo', () => 1))
expectType<() => number>(inject('foo', () => 1, false))
expectType<number>(inject('foo', () => 1, true))

// #8201
type Cube = {
  size: number
}

const injectionKeyRef = Symbol('key') as InjectionKey<Ref<Cube>>

// @ts-expect-error
provide(injectionKeyRef, ref({}))