rollup-plugin-react-scoped-css

Motivations

While using react in a professional context, I realized that it was lacking the scopped css feature that I learned to love from Vue and Angular. After some reasearch I came across good plugins, but sadly were not compatible with vite and/or rollup. Thus, I decided to create this plugin which was greatly inspired by the amazing work of gaoxiaoliangz with his react-scoped-css plugin.

Requirements

• node >= 18
• vite >= 5

How to install

$ npm i rollup-plugin-react-scoped-css

Simple Configuration

in vite:

// vite.config.js
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import { reactScopedCssPlugin } from 'rollup-plugin-react-scoped-css'

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [react(), reactScopedCssPlugin()]
})

in rollup:

// rollup.config.js
import reactScopedCssPlugin from 'rollup-plugin-react-scoped-css';

export default {
  input: 'src/input.js',
  output: { file: 'ouput.js' },
  plugins: [ reactScopedCssPlugin() ]
};

Notes: Because this plugin has been built with vite as its primary usecase, it doesn't transpile LESS, SCSS or other preprocessors. For that reason, you will likely need to add your transpilation plugins before reactScopedCssPlugin if you plan on using this without vite.

Customizing the plugin

There are a few options available to customize how the plugin works

{
  /**
   * Which files should be included and parsed by the plugin
   * Default: undefined
   */
  include?: FilterPattern;

  /**
   * Which files should be exluded and that should not be parsed by the plugin
   * Default: undefined
   */
  exclude?: FilterPattern;

  /**
   * If you want regular files to be scoped & global files to be .global.css
   * Default: false
   */
  scopeStyleByDefault?: boolean;

  /**
   * If you want to customize the pattern for scoped styles.
   * This will only work if scopeStyleByDefault is false
   * Default: 'scoped'
   */
  scopedStyleSuffix?: string;

  /**
   * If you want to customize the pattern for global styles.
   * This will only work if scopeStyleByDefault is true
   * Default: 'global'
   */
  globalStyleSuffix?: string;

  /**
   * If you want to customize the pattern for style files.
   * Default: ['css', 'scss', 'sass', 'less']
   */
  styleFileExtensions?: string[];

  /**
   * If you want to customize the pattern for jsx files.
   * Default: ['jsx', 'tsx']
   */
  jsxFileExtensions?: string[];

  /**
   * If you want to customize the attribute prefix that is added to the jsx elements
   * Default: 'v'
   */
  hashPrefix?: string;
}

Advanced Rollup usecases

Since this plugin works in two parts, you might need to expose the first part, then add any other plugin, and then expose the second part of the plugin. This part is automatically handled with vite thanks to the enforce attribute.

const reactScopedPlugins = reactScopedCssPlugin()
export default {
  //...
  plugins: [ reactScopedPlugins[0], {...stylingPlugins}, reactScopedPlugins[1] ]
};

Usage

// Component.jsx
import './Component.scoped.scss'

export default function Sub() {
  return (
    <div className="wrap">
      <h1>My Component</h1>
    </div>
  )
}

// Component.scoped.scss
.wrap {
  width: 500px;
  h1 { color: red; }
}

And just like that the styles will be scoped to the component.

Limitations

Due to the way this plugin is working, it will apply the scope to the file and not the component individually... This may differ from other frameworks since they don't really let you define multiple components in the same file. This then means that if you have 2 components in the same file, the styles might conflict.

Deep selector

If you want a selector in scoped styles to be "deep", i.e. affecting child components, you can use the ::deep combinator:

.a::deep .b { /* ... */ }

The above will be compiled into:

.a[data-f3f3eg9] .b { /* ... */ }

Another exepted format, which will generate the same resutl, is:

.a::v-deep .b { /* ... */ }

This is primarly for backwards compatibility, we recommend the ::deep selector.

Dynamically Generated Content

DOM content created with dangerouslySetInnerHTML are not affected by scoped styles, but you can still style them using deep selectors.

Also Keep in Mind

Scoped styles do not eliminate the need for classes. Due to the way browsers render various CSS selectors, p { color: red } will be many times slower when scoped (i.e. when combined with an attribute selector). If you use classes or ids instead, such as in .example { color: red }, then you virtually eliminate that performance hit.

Be careful with descendant selectors in recursive components! For a CSS rule with the selector .a .b, if the element that matches .a contains a recursive child component, then all .b in that child component will be matched by the rule.

Contributing

Anyone is free to open a PR and contribute to this project... just be civilized!