@prefecthq/prefect-ui-library/src/utilities/inject.ts

This library is the Vue and Typescript component library for [Prefect 2](https://github.com/PrefectHQ/prefect) and [Prefect Cloud 2](https://www.prefect.io/cloud/). _The components and utilities in this project are not meant to be used independently_.

import { inject as vueInject, InjectionKey, ComponentInternalInstance, getCurrentInstance } from 'vue'

export function inject<T>(key: InjectionKey<T> | string): T {
  const value = vueInject(key)

  if (value === undefined) {
    throw `Failed to inject value with key ${String(key)}`
  }

  return value
}

type ComponentInstanceWithProvide = ComponentInternalInstance & { provides: Record<string | symbol, unknown> } | null

export function injectFromSelfOrAncestor<T>(key: InjectionKey<T>): T {
  const vm = getCurrentInstance() as ComponentInstanceWithProvide
  const value = vm?.provides[key as symbol]

  if (value !== undefined) {
    return value as T
  }

  return inject(key)
}