element-plus/packages/utils/with-install.ts

import type { SFCWithInstall } from './types'

export const withInstall = <T, E extends Record<string, any>>(
  main: T,
  extra?: E
) => {
  ;(main as SFCWithInstall<T>).install = (app): void => {
    for (const comp of [main, ...Object.values(extra ?? {})]) {
      app.component(comp.name, comp)
    }
  }

  if (extra) {
    for (const [key, comp] of Object.entries(extra)) {
      ;(main as any)[key] = comp
    }
  }
  return main as SFCWithInstall<T> & E
}

export const withInstallFunction = <T>(fn: T, name: string) => {
  ;(fn as SFCWithInstall<T>).install = (app) => {
    app.config.globalProperties[name] = fn
  }

  return fn as SFCWithInstall<T>
}