Enable SASS or LESS support | Magento PWA Documentation

This tutorial provides the steps to enable SASS or LESS support in your storefront project.

Use these Webpack configurations to add support for SASS and LESS alongside CSS Modules.

Add SASS support

Step 1. Install dependencies

Use a package manager, such as yarn or npm, to install the SASS loader as a dev dependency.

yarn add --dev sass-loader node-sass

While installing the SASS loader you may get the error TypeError: this.getOptions is not a function. To resolve this error, just downgrade to version 10 of SASS loader. For this, edit package.json and change the version of sass-loader:

- "sass-loader": "^12.1.0"
+ "sass-loader": "^10.0.0"

Remove the node_modules folder and run:

yarn install

Or install sass-loader as a dev dependency with a specific version:

yarn add sass-loader@^10.0.0

Step 2. Modify the Webpack configuration

Edit webpack.config.js and add a new config rule entry:

    config.plugins = [
        ...config.plugins,
        new DefinePlugin({
            /**
             * Make sure to add the same constants to
             * the globals object in jest.config.js.
             */
            POSSIBLE_TYPES: JSON.stringify(possibleTypes),
            STORE_NAME: JSON.stringify('Venia')
        }),
        new HTMLWebpackPlugin({
            filename: 'index.html',
            template: './template.html',
            minify: {
                collapseWhitespace: true,
                removeComments: true
            }
        })
    ];
+
+   config.module.rules.push({
+       test: /\.s[ca]ss$/,
+       use: [
+           'style-loader',
+           {
+               loader: 'css-loader',
+               options: {
+                   modules: true,
+                   sourceMap: true,
+                   localIdentName: '[name]-[local]-[hash:base64:3]'
+               }
+           },
+           'sass-loader'
+       ]
+   });

Step 3. Create a SASS file and import it in a component

Create the myComponent.scss file:

$button-color: #ff495b;
$button-color-hover: #ff9c1a;

.root {
    padding: 15px;
}

.button {
    color: $button-color;

    &:hover {
        color: $button-color-hover;
    }
}

Create a component and import the SASS file:

import React from 'react';
import defaultClasses from './myComponent.scss';

const MyComponent = () => (
    <div className={defaultClasses.root}>
        <button className={defaultClasses.button}>My Component</button>
    </div>
);

export default MyComponent;

Add LESS support

Step 1. Install dependencies

Use a package manager, such as yarn or npm, to install the LESS loader as a dev dependency.

yarn add --dev less-loader less

Step 2. Modify the Webpack configuration

Edit webpack.config.js and add a new config rule entry:

    config.plugins = [
        ...config.plugins,
        new DefinePlugin({
            /**
             * Make sure to add the same constants to
             * the globals object in jest.config.js.
             */
            POSSIBLE_TYPES: JSON.stringify(possibleTypes),
            STORE_NAME: JSON.stringify('Venia')
        }),
        new HTMLWebpackPlugin({
            filename: 'index.html',
            template: './template.html',
            minify: {
                collapseWhitespace: true,
                removeComments: true
            }
        })
    ];
+
+   config.module.rules.push({
+       test: /\.less$/,
+       use: [
+           'style-loader',
+           {
+               loader: 'css-loader',
+               options: {
+                   modules: true,
+                   sourceMap: true,
+                   localIdentName: '[name]-[local]-[hash:base64:3]'
+               }
+           },
+           'less-loader'
+       ]
+   });

Step 3. Create a LESS file and import it on your component

Create the myComponent.less file:

@button-color: #ff495b;
@button-color-hover: #ff9c1a;

.root {
    padding: 15px;
}

.button {
    color: @button-color;

    &:hover {
        color: @button-color-hover;
    }
}

Create a component and import the LESS file:

import React from 'react';
import defaultClasses from './myComponent.less';

const MyComponent = () => (
    <div className={defaultClasses.root}>
        <button className={defaultClasses.button}>My Component</button>
    </div>
);

export default MyComponent;