Converts React components using imported CSS stylesheets to equivalent CSS Modules syntax.

Given this (simpilified) CSS file and React component:

/* button.css */
.button {
	flex: 1;
	background-color: #eee;
	color: #222;
}

/* button.tsx */
import "./button.css";

export default ({ children }) => <div className="button">{children}</div>;

It will product the following, modified component:

/* button.tsx */
import * as styles from "./button.css";

export default ({ children }) => (
	<div className={styles["button"]}>{children}</div>
);

Running the following command will codemod all files in dir/ (Make sure they're checked into source control!):

npx codemod -p babel-plugin-codemod-react-css-modules dir/

You can also pass options to the plugin like so

npx codemod \
	-p babel-plugin-codemod-react-css-modules \
	-o react-css-modules='{ "importIdentifier": "css" }' \
	path/to/file

Or store them in a file e.g. options.json and reference them using the @ syntax:

npx codemod \
	-p babel-plugin-codemod-react-css-modules \
	-o [email protected] \
	path/to/file

For a list of valid options see src/index.ts:PluginOptions

The plugin will attempt to convert any string literals specifically that have a value within the list of CSS class names of the imported .css file.

It will also attempt to process strings within variables referenced in the className expression e.g. className={className} will result in the scoped className variable being recursively processed as outlined above.

This logic is scoped to only affect statements within JSX className declarations, which might not pick up 100% of edge cases. In particular, it won't pick up stuff like... className={"button--"+variant}, since the full class name wouldn't be known until runtime. You'll need to handle this case manually

This plugin uses postcss and the postcss-modules plugin to get a list of valid CSS class names from the imported .css file. If it isn't picking up one of your classes, you might need to include a custom postcss plugin to handle your CSS. See below for details.

You'll need to modify your webpack or other bundling environment to load the CSS files using the CSS Modules specification for this to work once the codemod is done.

css-loader supports CSS Modules out the box, or if you prefer you can use postcss-loader and the postcss-modules plugin instead.

Yes, the plugin will look for your postcss.config.js file (or similar) thanks to it using the postcss-load-config module.

Yes, see above.

Yes, see PluginOptions in src/index.ts