Node.js JSX Require Hook

Common errors

• Error: Cannot find module 'react/lib/ReactContext'

  cause Attempting to use `node-jsx` with modern React versions (>=0.14) which changed internal module structures significantly.
  fix Upgrade your JSX transpilation pipeline entirely. `node-jsx` is incompatible with modern React. Use Babel or TypeScript instead.

• SyntaxError: Unexpected token '<'

  cause Node.js attempting to parse a `.jsx` file directly without the `node-jsx` hook being correctly installed or because the file type isn't registered for transpilation.
  fix Ensure `require('node-jsx').install()` is executed *before* any `.jsx` files are `require()`d. However, this only applies to the severely outdated setup. For modern projects, this error means your build/transpilation step is misconfigured.

• TypeError: Cannot read properties of undefined (reading 'install')

  cause The `require('node-jsx')` call did not return an object with an `install` method. This could be due to a faulty installation or an attempt to use `import` with a CommonJS-only package.
  fix Verify that `node-jsx` is correctly installed (`npm install node-jsx`). Ensure you are using `require('node-jsx').install()` and not `import` syntax.

Warnings

• breaking This package is officially deprecated and completely unmaintained since 2015. It is incompatible with modern React versions (>=0.14) and contemporary JavaScript/JSX syntax.
  Fix: Migrate to a modern build setup using Babel (with @babel/preset-react) or TypeScript (with 'jsx' compiler option) and a bundler like Webpack or Vite. For server-side rendering, pre-transpile components or use `@babel/register` (for older Babel) or `ts-node` (for TypeScript) with appropriate configurations.
• breaking The `harmony: true` option mentioned in its README for ES6 transforms is severely outdated and will not correctly process modern ES6+ or JSX features (e.g., Fragments, Hooks, spread attributes).
  Fix: See the general fix for deprecation: use modern transpilers that support current ECMAScript and JSX specifications.
• gotcha This package exclusively supports CommonJS (`require()`) and cannot be used with ES Modules (`import`). Node.js projects using ES Modules will not be able to utilize this hook.
  Fix: If your project uses ES Modules, this package is fundamentally incompatible. Use modern build tools that natively support ES Modules and JSX transformation.
• gotcha Using `node-jsx` for on-the-fly transpilation in production Node.js applications will incur significant performance overhead, as every `require()` of a JSX file involves a parsing and transformation step.
  Fix: Always pre-transpile JSX files to plain JavaScript using a build step before deploying to production. Runtime transpilation should only be considered for development environments, and even then, modern alternatives offer better performance and compatibility.

Install

• npm install node-jsx npm
• yarn add node-jsx yarn
• pnpm add node-jsx pnpm

Imports

• install
  wrong:

  import { install } from 'node-jsx';

  correct:

  require('node-jsx').install();

  This package is CommonJS-only and exposes its functionality directly via `require()`. There is no ES Module equivalent.
• installWithOptions
  wrong:

  const jsx = require('node-jsx'); jsx.install({ ... });

  correct:

  require('node-jsx').install({ extension: '.jsx', harmony: true });

  While functional, chaining `.install()` directly on the `require()` call is the idiomatic usage shown in its documentation.

Quickstart

Demonstrates the deprecated method of installing `node-jsx` to enable on-the-fly JSX transpilation for `require()` calls in Node.js, highlighting its obsolescence.

const path = require('path');
const fs = require('fs');

// Install the node-jsx require hook
require('node-jsx').install({ harmony: true });

// Imagine a simple JSX component file at src/MyComponent.jsx
// const React = require('react');
// module.exports = function MyComponent({ name }) { return <div>Hello, {name}!</div>; };

// This package is for JSX transpilation only, it does not include React itself.
// Trying to require modern React or a JSX file directly will likely fail
// due to incompatibilities and missing React runtime. This example demonstrates
// the setup, but requires a legacy React setup to actually run JSX.

// For demonstration, let's pretend a legacy React is available.
// In a real modern scenario, this setup is completely obsolete.

console.log('node-jsx require hook installed. This setup is highly deprecated.');
console.log('Modern projects use Babel/TypeScript for JSX transpilation.');