Using Preact with Storybook 3

Preact works wonders for projects where we want the component architecture from React, but need a very small bundle footprint. One good example of this is our identity-widget. Since it’s an embeddable widget, the full bundle weight of a typical single page application would be way too much and would harm performance on sites using it.

Another library we use heavily at Netlify is Storybook. Being able to work on the UI of components in isolation from application state is liberating, and makes it much easier to take things like error paths, validations, and edge cases into account when building and testing UI components. We use it religiously for our main web app.

Storybook is built for React, however. So what if we wanted to use it for our Preact-based widgets?

Preact / React compatibility

The key to making this work is a library called preact-compat that offers a wrapper around Preact that mimics the API of the react and react-dom libraries.

The way to use it, is to tell webpack to cheat, and import preact-compat whenever a file is trying to import either react or react-dom.

You can read more about preact-compat and how to generally use it with webpack in their documentation.

Getting Storybook to use preact-compat

How do you get webpack set up with this? I’m going to assume you have an existing project based on Preact and webpack, and then show the steps to set up Storybook from scratch.

Start by installing storybook and preact-compat:

yarn add -D @storybook/react preact-compat

Once the dependencies are in place, create a .storybook/config.js file with the standard storybook config:

import { configure } from '@storybook/react';

function loadStories() {
  require('../stories/index.js');
  // You can require as many stories as you need.
}

configure(loadStories, module);

Now you need to extend storybook’s config to use the Preact based loader. Storybook lets you do this by defining a .storybook/webpack.config.js file and export an object with overwrites of their base config.

Our goal by customizing the webpack config, is to inject the resolver so react and react-dom gets replaced with preact-compat when building our stories.

To do that, create this file and save it as .storybook/webpack.config.js:

module.exports = {
  resolve: {
    extensions: [".js", "jsx"],
    alias: {
      react: "preact-compat",
      "react-dom": "preact-compat"
    }
  }
};

Writing Stories

All that’s left to do now is write stories and run your storybook.

To get started with this, create a file stories/index.js:

import { h } from "preact";
import { storiesOf } from "@storybook/react";

storiesOf("Storybook With Preact", module)
    .add("render some text", () => <h1>Hello, Preact World!</h1>)

And add a storybook script in the "``scripts``" section of your package.json:

"scripts": {
  "storybook": "start-storybook -p 9001 -c .storybook"
}

Now you can run yarn storybook and visit localhost:9001 to view your Preact based stories.