Nuxt/packages/nuxt/src/pages/runtime/utils.ts

import { KeepAlive, h } from 'vue'
import { RouterView, RouteLocationMatched, RouteLocationNormalizedLoaded } from 'vue-router'

type InstanceOf<T> = T extends new (...args: any[]) => infer R ? R : never
export type RouterViewSlotProps = Parameters<InstanceOf<typeof RouterView>['$slots']['default']>[0]

const interpolatePath = (route: RouteLocationNormalizedLoaded, match: RouteLocationMatched) => {
  return match.path
    .replace(/(:\w+)\([^)]+\)/g, '$1')
    .replace(/(:\w+)[?+*]/g, '$1')
    .replace(/:\w+/g, r => route.params[r.slice(1)]?.toString() || '')
}

export const generateRouteKey = (override: string | ((route: RouteLocationNormalizedLoaded) => string), routeProps: RouterViewSlotProps) => {
  const matchedRoute = routeProps.route.matched.find(m => m.components.default === routeProps.Component.type)
  const source = override ?? matchedRoute?.meta.key ?? interpolatePath(routeProps.route, matchedRoute)
  return typeof source === 'function' ? source(routeProps.route) : source
}

export const wrapInKeepAlive = (props: any, children: any) => {
  return { default: () => process.client && props ? h(KeepAlive, props === true ? {} : props, children) : children }
}