Allow Document as container for createRoot

previously rendering into Document was broken and only hydration worked because React did not properly deal with the documentElement and would error in a broken state if used that way. With the previous commit addressing this limitation this change re-adds Document as a valid container for createRoot. It should be noted that if you use document with createRoot it will drop anything a 3rd party scripts adds the page before rendering for the first time.

Author: gnoff

packages/react-dom/client.js

@@ -23,7 +23,7 @@ import {
 } from './';
 
 export function createRoot(
- container: Element | DocumentFragment,
+ container: Element | Document | DocumentFragment,
  options?: CreateRootOptions,
 ): RootType {
  if (__DEV__) {

packages/react-dom/src/client/ReactDOM.js

@@ -148,7 +148,7 @@ const Internals = {
 };
 
 function createRoot(
- container: Element | DocumentFragment,
+ container: Element | Document | DocumentFragment,
  options?: CreateRootOptions,
 ): RootType {
  if (__DEV__) {

packages/react-dom/src/client/ReactDOMRoot.js

@@ -164,7 +164,7 @@ ReactDOMHydrationRoot.prototype.unmount = ReactDOMRoot.prototype.unmount = funct
 };
 
 export function createRoot(
- container: Element | DocumentFragment,
+ container: Element | Document | DocumentFragment,
  options?: CreateRootOptions,
 ): RootType {
  if (!isValidContainer(container)) {