Nuxt/packages/nuxt/src/app/compat/capi.ts

export * from 'vue'

export const install = () => {}

export function set (target, key, val) {
  if (Array.isArray(target)) {
    target.length = Math.max(target.length, key)
    target.splice(key, 1, val)
    return val
  }
  target[key] = val
  return val
}

export function del (target, key) {
  if (Array.isArray(target)) {
    target.splice(key, 1)
    return
  }
  delete target[key]
}