# react-component-library

**Repository Path**: dbody/react-component-library

## Basic Information

- **Project Name**: react-component-library
- **Description**: Getting Started with React Component Library
- **Primary Language**: JavaScript
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-04-13
- **Last Updated**: 2022-05-24

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# React Component Library


This project skeleton was created to help people get started with creating their own React component library using:

- [Rollup](https://github.com/rollup/rollup)
- [Sass](https://sass-lang.com/)
- [TypeScript](https://www.typescriptlang.org/)

It also features:

- [Storybook](https://storybook.js.org/) to help you create and show off your components
- [Jest](https://jestjs.io/) and [React Testing Library](https://github.com/testing-library/react-testing-library) enabling testing of the components

## Development

### Testing

```
npm run test
```

### Building

```
npm run build
```

### Storybook

To run a live-reload Storybook server on your local machine:

```
npm run storybook
```

To export your Storybook as static files:

```
npm run storybook:export
```

### Generating New Components

I've included a handy NodeJS util file under `util` called `create-component.js`. Instead of copy pasting components to create a new component, you can instead run this command to generate all the files you need to start building out a new component. To use it:

```
npm run create YourComponentName
```

This will create:

```
/src
  /YourComponentName
    YourComponentName.tsx
    YourComponentName.stories.tsx
    YourComponentName.test.tsx
    YourComponentName.types.ts
    YourComponentName.scss
```

The default templates for each file can be modified under `util/templates`.

Don't forget to add the component to your `index.ts` exports if you want the library to export the component!

### Installing Component Library Locally

Let's say you have another project (`test-app`) on your machine that you want to try installing the component library into without having to first publish the component library. In the `test-app` directory, you can run:

```
npm i --save ../react-component-library
```

which will install the local component library as a dependency in `test-app`. It'll then appear as a dependency in `package.json` like:

```
  ...
  "dependencies": {
    ...
    "react-component-library": "file:../react-component-library",
    ...
  },
  ...
```

Your components can then be imported and used in that project.

**NOTE**: After installing the component library locally, you may run into:

```
Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for one of the following reasons:

You might have mismatching versions of React and the renderer (such as React DOM)
You might be breaking the Rules of Hooks
You might have more than one copy of React in the same app See for tips about how to debug and fix this problem.
```

This is the most commonly encountered problem people face when installing the library locally. This is most likely due to the third reason: `You might have more than one copy of React in the app`.

Normally when a library is published, dev dependencies are excluded. However, when the library is symlinked, all local dev depdendencies are persisted in the libraries `node_modules` (includes React). Your bundler may see two versions of React, one in the consuming app and one in the symlinked library. The solution is to have the component library use the React version in the consuming app. So from your component library folder, run:

```
npm link ../test-app/node_modules/react
```

## Usage

Let's say you created a public NPM package called `react-component-library` with the `TestComponent` component created in this repository.

Usage of the component (after the library installed as a dependency into another project) will be:

```TSX
import React from "react";
import { TestComponent } from "react-component-library";

const App = () => (
  <div className="app-container">
    <h1>Hello I'm consuming the component library</h1>
    <TestComponent theme="primary" />
  </div>
);

export default App;
```

[Check out this Code Sandbox for a live example.](https://codesandbox.io/s/react-component-library-example-y2b60?file=/src/App.js)

### Using Component Library SASS Variables

I've found that it's helpful to export SASS variables to projects consuming the library. As such, I've added the `rollup-plugin-copy` NPM package and used it to copy the [`src/typography.scss`](src/typography.scss) and [`variables.scss`](src/variables.scss) into the `build` directory as part of the Rollup bundle process. This allows you to use these variables in your projects consuming the component library.

For example, let's say you installed `react-component-library` into your project. To use the exported variables/mixins, in a SASS file you would do the following:

```Sass
@import '~react-component-library/build/typography';

.example-container {
    @include heading;

    color: $react-white;
}
```

## Additional Help

### Dark Mode

The example component `TestComponent` respects the user's dark mode operating system preferences and renders the component in the appropriate theme.

This is achieved by using the media query: `@media (prefers-color-scheme: dark)` in combination with CSS variables. The colours that change depending on dark mode preference can be found in [`src/variables.scss`](src/variables.scss). Example usage of these variables can be found within [`src/TestComponent/TestComponent.scss`](src/TestComponent/TestComponent.scss).

Read https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme for more details.

### Using Alternatives to Sass

#### Less or Stylus

The Rollup plugin `rollup-plugin-postcss` supports Sass, Less and Stylus:

- For Stylus, install stylus: `yarn add stylus --dev`
- For Less, install less: `yarn add less --dev`

You can then remove `node-sass` from your dependencies.

#### CSS Modules

If you want to use CSS Modules, update `postcss` in `rollup-config.js` to:

```
postcss({
  modules: true
})
```

#### Styled Components

If you want to use [`styled-components`](https://styled-components.com/), the changes required are a bit more involved. As such, I've created a branch where I've got `styled-components` working in this component library.

### Component Code Splitting

Code splitting of your components is not supported by default.

import components in isolation like:

```
import TestComponent from 'react-component-library/build/TestComponent';
```

This can reduce the bundle size for projects using older (CJS) module formats.

Please note, there's an issue with code splitting and using `rollup-plugin-postcss`. I recommend using `rollup-plugin-sass` instead alongside code splitting.

### Supporting Image Imports

Add the following library to your component library [@rollup/plugin-image](https://github.com/rollup/plugins/tree/master/packages/image):

```
npm i -D @rollup/plugin-image
```

Then add it to `rollup-config.js`:

```
...
plugins:[
  ...,
  image(),
  ...
]
...
```

You can then import and render images in your components like:

```tsx
import logo from "./rollup.png";

export const ImageComponent = () => (
  <div>
    <img src={logo} />
  </div>
);
```

### Supporting JSON Imports

Add the following library to your component library [@rollup/plugin-json](https://github.com/rollup/plugins/tree/master/packages/json):

```
npm i -D @rollup/plugin-json
```

Then add it to `rollup-config.js`:

```
...
plugins:[
  ...,
  json(),
  ...
]
...
```

You can then import and use JSON as ES6 Modules:

```tsx
import data from "./some-data.json";

export const JsonDataComponent = () => <div>{data.description}</div>;
```

Checkout the [official Rollup plugin list](https://github.com/rollup/plugins) for additional helpful plugins.