React Uncaught Error: Minified React error #418 #423

Introduction

While developing this blog utilizing React for Server-Side Rendering (SSR) and Hydration, I encountered the following errors: Uncaught Error: Minified React error #418 and #423. These errors predominantly occur when there's a mismatch between client-side and server-side rendering, specifically when using the hydrateRoot function from react-dom/client.

Understanding Rehydration

Rehydration is the phase where the client-side code takes over and attaches event handlers to the HTML markup initially rendered on the server. A mismatch between the client-side rendering and server-side markup often leads to the aforementioned errors.

Addressing the Errors

Upon encountering these errors, I reverted to using the hydrate function from react-dom which resolved the issues seamlessly. Below is the change I made in the code:

import React from 'react';
-import { hydrateRoot } from 'react-dom/client';
+import { hydrate } from 'react-dom';
import ReactDOM from 'react-dom';
import App from './App';

-hydrateRoot(
+hydrate(
-  document.getElementById('root'),
  <App />, 
+  document.getElementById('root'),
);

Delving Deeper into hydrateRoot

The hydrateRoot method was introduced in React version [email protected]. This method facilitates displaying React components within a browser DOM node, the HTML content of which was previously generated by react-dom/server. The syntax to utilize hydrateRoot is hydrateRoot(container, element), which replaced the earlier hydrate method exported from react-dom/client.

hydrateRoot aims at bolstering concurrency and better supporting the selective hydration process. Selective hydration is crucial for enhancing the performance, search engine optimization (SEO), and user experience (UX) of React applications employing Server-Side Rendering (SSR). The hydrateRoot method provides a more refined mechanism to attach React to existing HTML, initially rendered by React in a server environment, thereby allowing React to manage the DOM within the specified domNode.

Moreover, hydrateRoot necessitates that the rendered content aligns perfectly with the server-rendered content. Any discrepancies should be perceived as bugs and rectified promptly. This underscores the essence of ensuring a match between the server and client render to avert rehydration errors.

The advent of hydrateRoot mirrors React's progressive approach towards handling server-rendered HTML, striving to equip developers with superior tools for crafting performant, SEO-friendly, and user-centric applications.