es-react

An ES6 module exposing the latest version of react, react-dom, react-is, and prop-types

Ever wanted to just import react into your project as a module without a build step or even script tags? Native browser support for module imports is pretty good so this should be an option for react developers now! Alas, there has not been an ES6 module compatible build released yet.

This package allows you import react and react-dom as ES6 modules from a CDN like unpkg:

<script type="module">
  import { React, ReactDOM, PropTypes } from 'https://unpkg.com/es-react';

  ReactDOM.render(
    React.createElement('h1', {}, 'Hello from es-react'),
    document.body
  );
</script>

By default es-react exports the production build of react. For the development build use the /dev subfolder:

import { React, ReactDOM } from 'https://unpkg.com/es-react/dev';

You may also import any members of the React package directly:

import React, {
  Component,
  useState /* ... */,
} from 'https://unpkg.com/es-react';

And every package is also being provided as a separate file:

• es-react/index.js: Exports all of React and exports { React, ReactDOM, ReactIs, PropTypes }
• es-react/react.js: Exports all of React plus a default export
• es-react/react-dom.js: Exports all of ReactDOM plus a default export (but not react-dom/server)
• es-react/react-is.js: Exports all of ReactIs plus a default export
• es-react/prop-types.js: Exports all of PropTypes plus a default export
• es-react/react-dom-server.js: Exports all of ReactDOMServerBrowser plus a default export

All development-versions of these packages are also available under es-react/dev/.

Features

• All the latest React features (hooks, suspense, lazy, memo etc.)
• Use React directly from any javascript file (no build step required)
• Compatible with htm (for JSX compilation at runtime)

Usage

Import React and ReactDOM directly from any script with type="module". The package is intended to be available from unpkg (without having to append ?module to the package name).

import { React, ReactDOM } from 'https://unpkg.com/[email protected]';

It is strongly advised that you specify a version when requesting the module – this speeds up the request time and helps with caching. If you don't specify a number then unpkg will redirect and serve up the latest available version.

Example

Create a new file, copy the code below into it and then open the file in a browser – or try online.

If you would like the browser to reload when you update the code, then you can use a dev server like servor dependency free by running npx servor --reload --browse.

<script type="module">
  import { React, ReactDOM } from 'https://unpkg.com/[email protected]';

  import htm from 'https://unpkg.com/htm?module'
  const html = htm.bind(React.createElement)

  const Counter = props => {
    const [count, setCount] = React.useState(parseInt(props.count))
    return html`
      <div>
        <h1>${count}</h1>
        <button onClick=${e => setCount(count - 1)}>Decrement</button>
        <button onClick=${e => setCount(count + 1)}>Increment</button>
      </div>
    `
  }

  ReactDOM.render(
    html`
      <h1>Look Ma! No script tags, no build step</h1>
      <${Counter} count=0 />
    `,
    document.body
  )

</script>

Implementation

The latest versions of all packages are installed via (pinned) entries in package.json and built and bundled using Rollup with automatic code splitting.

The exports of each package are automatically expanded and object-assign is stripped from the output, since all browsers that support ESM will also support Object.assign (See scripts/expand-exports-plugin.js and scripts/replace-object-assign.js for the Babel plugins that do this)

Acknowledgements

Barely any of the code in this repo is written by myself. It is just a wrapper for React that is written and maintained by the team at Facebook. Thanks to my employer Formidable for allowing me the time to think about and work on fun and experimental projects like this.