swc-plugin-css-modules

swc-plugin-css-modules

A SWC plugin to use CSS Modules.

Instead of creating an object, the plugin injects the css class names directly into the js code. This allows to reduce the size of the bundle.

// Input Code
import styles from "./style.css";
element.innerHTML = '<div class="' + styles.className + '">';

// Output   ↓ ↓ ↓ ↓ ↓ ↓
import "./style.css";
element.innerHTML = '<div class="' + "style__className___clZD5" + '">';

Installation

npm:

npm i -D swc-plugin-css-modules

yarn:

yarn add -D swc-plugin-css-modules

You can check the compatibility of versions on https://plugins.swc.rs/

Usage

Via .swcrc

{
  "jsc": {
    "experimental": {
      "plugins": [
        [
          "swc-plugin-css-modules",
          {
            "generate_scoped_name": "[name]__[local]___[hash:base64:5]"
          }
        ]
      ]
    }
  }
}

Using css modules in code:

import styles from "./style.module.css";

// ✅ ok
const className = styles.className;

// ✅ ok
const className = styles["class-name"];

// ⛔ Computed hit cannot be injected
const className = styles["class" + "Name"];

// ⛔ Computed hit cannot be injected
const className = styles[localClassName];

// ✅ ok
const className = classNames(styles.title, styles.className);

// ⛔ Computed hit cannot be injected
const className = getClassNameFromCssModules(styles);

Options

generate_scoped_name

Default: "[hash:base64]"

Allows to configure the generated local ident name.

Supported template strings:

• [name] the basename of the resource
• [folder] the folder the resource relative
• [ext] - extension with leading
• [hash] - the hash of the string(by default it's the hex digest of the xxhash64 hash)
• [<hashFunction>:hash:<hashDigest>:<hashDigestLength>] - hash with hash settings
• [local] - original class

Supported hash functions:

• xxhash64
• md4
• md5
• sha1
• sha224
• sha256
• sha384
• sha512

Supported hash digests:

• hex
• base32
• base64

hash_prefix

Add custom hash prefix to generate more unique classes.

css_modules_suffix

Default: ".css"

root

If you need, you can pass any needed root path.