Function warnIfReactDOMContainerInDEV

packages/react-dom/src/client/ReactDOMRoot.js:360–377

(container: any)

}

function warnIfReactDOMContainerInDEV(container: any) {
  if (__DEV__) {
    if (isContainerMarkedAsRoot(container)) {
      if (container._reactRootContainer) {
        console.error(
          'You are calling ReactDOMClient.createRoot() on a container that was previously ' +
            'passed to ReactDOM.render(). This is not supported.',
        );
      } else {
        console.error(
          'You are calling ReactDOMClient.createRoot() on a container that ' +
            'has already been passed to createRoot() before. Instead, call ' +
            'root.render() on the existing root instead if you want to update it.',
        );
      }
    }
  }
}