Function createCompatVue

packages/runtime-core/src/compat/global.ts:143–330

(
  createApp: CreateAppFunction<Element>,
  createSingletonApp: CreateAppFunction<Element>,
)

// Legacy global Vue constructor
export function createCompatVue(
  createApp: CreateAppFunction<Element>,
  createSingletonApp: CreateAppFunction<Element>,
): CompatVue {
  singletonApp = createSingletonApp({})

  const Vue: CompatVue = (singletonCtor = function Vue(
    options: ComponentOptions = {},
  ) {
    return createCompatApp(options, Vue)
  } as any)

  function createCompatApp(options: ComponentOptions = {}, Ctor: any) {
    assertCompatEnabled(DeprecationTypes.GLOBAL_MOUNT, null)

    const { data } = options
    if (
      data &&
      !isFunction(data) &&
      softAssertCompatEnabled(DeprecationTypes.OPTIONS_DATA_FN, null)
    ) {
      options.data = () => data
    }

    const app = createApp(options)

    if (Ctor !== Vue) {
      applySingletonPrototype(app, Ctor)
    }

    const vm = app._createRoot!(options)
    if (options.el) {
      return (vm as any).$mount(options.el)
    } else {
      return vm
    }
  }

  Vue.version = `2.6.14-compat:${__VERSION__}`
  Vue.config = singletonApp.config

  Vue.use = (plugin: Plugin, ...options: any[]) => {
    if (plugin && isFunction(plugin.install)) {
      plugin.install(Vue as any, ...options)
    } else if (isFunction(plugin)) {
      plugin(Vue as any, ...options)
    }
    return Vue
  }

  Vue.mixin = m => {
    singletonApp.mixin(m)
    return Vue
  }

  Vue.component = ((name: string, comp: Component) => {
    if (comp) {
      singletonApp.component(name, comp)