wip: whitespace behavior compat

packages/vue-compat/src/createCompatVue.ts

@@ -0,0 +1,46 @@
+// This entry exports the runtime only, and is built as
+// `dist/vue.esm-bundler.js` which is used by default for bundlers.
+import { initDev } from './dev'
+import {
+  compatUtils,
+  createApp,
+  Transition,
+  TransitionGroup,
+  KeepAlive,
+  DeprecationTypes,
+  vShow,
+  vModelDynamic
+} from '@vue/runtime-dom'
+import { extend } from '@vue/shared'
+
+if (__DEV__) {
+  initDev()
+}
+
+import * as runtimeDom from '@vue/runtime-dom'
+
+function wrappedCreateApp(...args: any[]) {
+  // @ts-ignore
+  const app = createApp(...args)
+  if (compatUtils.isCompatEnabled(DeprecationTypes.RENDER_FUNCTION, null)) {
+    // register built-in components so that they can be resolved via strings
+    // in the legacy h() call. The __compat__ prefix is to ensure that v3 h()
+    // doesn't get affected.
+    app.component('__compat__transition', Transition)
+    app.component('__compat__transition-group', TransitionGroup)
+    app.component('__compat__keep-alive', KeepAlive)
+    // built-in directives. No need for prefix since there's no render fn API
+    // for resolving directives via string in v3.
+    app._context.directives.show = vShow
+    app._context.directives.model = vModelDynamic
+  }
+  return app
+}
+
+export function createCompatVue() {
+  const Vue = compatUtils.createCompatVue(wrappedCreateApp)
+  extend(Vue, runtimeDom)
+  // @ts-ignore
+  Vue.createApp = wrappedCreateApp
+  return Vue
+}