stylus-loader

A Stylus loader for webpack. Compiles Stylus files into CSS.

Getting Started

To begin, you'll need to install stylus and stylus-loader:

npm install stylus stylus-loader --save-dev

or

yarn add -D stylus stylus-loader

or

pnpm add -D stylus stylus-loader

Then add the loader to your webpack configuration. For example:

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl$/,
        loader: "stylus-loader", // compiles Styl to CSS
      },
    ],
  },
};

Finally, run webpack using the method you normally use (e.g., via CLI or an npm script).

Options

• stylusOptions
• sourceMap
• webpackImporter
• additionalData
• implementation

stylusOptions

Type:

type stylusOptions =
  | {
      use: (string | ((stylusOptions: StylusOptions) => void))[];
      include: string[];
      import: string[];
      define: any[];
      includeCSS: false;
      resolveURL: boolean | object;
      lineNumbers: boolean;
      hoistAtrules: boolean;
      compress: boolean;
    }
  | ((loaderContext: LoaderContext) => string[]);

Default: {}

You can pass any Stylus specific options to the stylus-loader through the stylusOptions property in the loader options.

See the Stylus documentation.

Options in dash-case should be written in camelCase.

object

Use an object to pass options through to Stylus.

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl$/,
        use: [
          {
            loader: "style-loader",
          },
          {
            loader: "css-loader",
          },
          {
            loader: "stylus-loader",
            options: {
              stylusOptions: {
                // eslint-disable-next-line jsdoc/no-restricted-syntax
                /**
                 * Specify Stylus plugins to use. Plugins may be passed as
                 * strings instead of importing them in your Webpack config.
                 * @type {(string | (renderer: object) => void)[]}
                 * @default []
                 */
                use: ["nib"],

                /**
                 * Add path(s) to the import lookup paths.
                 * @type {string[]}
                 * @default []
                 */
                include: [path.join(__dirname, "src/styl/config")],

                /**
                 * Import the specified Stylus files/paths.
                 * @type {string[]}
                 * @default []
                 */
                import: ["nib", path.join(__dirname, "src/styl/mixins")],

                /**
                 * Define Stylus variables or functions.
                 * @type {[string, string | number | boolean, boolean?] | Record<string, string | number | boolean>}
                 * @default {}
                 */
                // Array is the recommended syntax: [key, value, raw]
                define: [
                  ["$development", process.env.NODE_ENV === "development"],
                  ["rawVar", 42, true],
                ],
                // Object is deprecated syntax (there is no possibility to specify "raw')
                // define: {
                //   $development: process.env.NODE_ENV === 'development',
                //   rawVar: 42,
                // },

                /**
                 * Include regular CSS on \@import.
                 * @type {boolean}
                 * @default false
                 */
                includeCSS: false,

                /**
                 * Resolve relative url()'s inside imported files.
                 * @see https://stylus-lang.com/docs/js.html#stylusresolveroptions
                 * @type {boolean | { nocheck?: boolean, paths?: string[] }}
                 * @default { nocheck: true }
                 */
                resolveURL: true,
                // resolveURL: { nocheck: true },

                /**
                 * Emits comments in the generated CSS indicating the corresponding Stylus line.
                 * @see https://stylus-lang.com/docs/executable.html
                 * @type {boolean}
                 * @default false
                 */
                lineNumbers: true,

                /**
                 * Move \@import and \@charset to the top.
                 * @see https://stylus-lang.com/docs/executable.html
                 * @type {boolean}
                 * @default false
                 */
                hoistAtrules: true,

                /**
                 * Compress CSS output.
                 * In the "production" mode is `true` by default
                 * @see https://stylus-lang.com/docs/executable.html
                 * @type {boolean}
                 * @default false
                 */
                compress: true,
              },
            },
          },
        ],
      },
    ],
  },
};

function

Allows setting the options passed through to Stylus based off of the loader context.

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl/,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "stylus-loader",
            options: {
              stylusOptions: (loaderContext) => {
                // More information about available properties https://webpack.js.org/api/loaders/
                const { resourcePath, rootContext } = loaderContext;
                const relativePath = path.relative(rootContext, resourcePath);

                if (relativePath === "styles/foo.styl") {
                  return {
                    paths: ["absolute/path/c", "absolute/path/d"],
                  };
                }

                return {
                  paths: ["absolute/path/a", "absolute/path/b"],
                };
              },
            },
          },
        ],
      },
    ],
  },
};

sourceMap

Type:

type sourceMap = boolean;

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl$/i,
        use: [
          "style-loader",
          {
            loader: "css-loader",
            options: {
              sourceMap: true,
            },
          },
          {
            loader: "stylus-loader",
            options: {
              sourceMap: true,
            },
          },
        ],
      },
    ],
  },
};

webpackImporter

Type:

type webpackImporter = boolean;

Default: true

Enables/disables the default Webpack importer.

This can improve performance in some cases. Use it with caution because aliases and @import at-rules starting with ~ will not work.

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl/i,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "stylus-loader",
            options: {
              webpackImporter: false,
            },
          },
        ],
      },
    ],
  },
};

additionalData

Type:

type additionalData =
  | string
  | ((
      content: string | Buffer,
      loaderContext: LoaderContext,
      meta: any,
    ) => string);

Default: undefined

Prepends Stylus code before the actual entry file. In this case, the stylus-loader will not override the source but will simply prepend the entry's content.

This is especially useful when some of your Stylus variables depend on the environment.

[!NOTE]

Since you're injecting code, this will break the source mappings in your entry file. Often there's a simpler solution than this, such as using multiple Stylus entry files.

string

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl/,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "stylus-loader",
            options: {
              additionalData: `@env: ${process.env.NODE_ENV};`,
            },
          },
        ],
      },
    ],
  },
};

function

Sync

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl/,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "stylus-loader",
            options: {
              additionalData: (content, loaderContext) => {
                // More information about available properties https://webpack.js.org/api/loaders/
                const { resourcePath, rootContext } = loaderContext;
                const relativePath = path.relative(rootContext, resourcePath);

                if (relativePath === "styles/foo.styl") {
                  return `value = 100px${content}`;
                }

                return `value = 200px${content}`;
              },
            },
          },
        ],
      },
    ],
  },
};

Async

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl/,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "stylus-loader",
            options: {
              additionalData: async (content, loaderContext) => {
                // More information about available properties https://webpack.js.org/api/loaders/
                const { resourcePath, rootContext } = loaderContext;
                const relativePath = path.relative(rootContext, resourcePath);

                if (relativePath === "styles/foo.styl") {
                  return `value = 100px${content}`;
                }

                return `value = 200px${content}`;
              },
            },
          },
        ],
      },
    ],
  },
};

implementation

Type:

type implementation = (() => typeof import("stylus")) | string;

The implementation option allows you to specify which Stylus implementation to use. It overrides the locally installed peerDependency version of stylus.

function

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl/i,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "stylus-loader",
            options: {
              implementation: require("stylus"),
            },
          },
        ],
      },
    ],
  },
};

string

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl/i,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "stylus-loader",
            options: {
              implementation: require.resolve("stylus"),
            },
          },
        ],
      },
    ],
  },
};

Examples

Normal Usage

Chain stylus-loader with the css-loader and style-loader to immediately apply all styles to the DOM.

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl$/,
        use: [
          {
            loader: "style-loader", // creates style nodes from JS strings
          },
          {
            loader: "css-loader", // translates CSS into CommonJS
          },
          {
            loader: "stylus-loader", // compiles Stylus to CSS
          },
        ],
      },
    ],
  },
};

Source maps

To enable sourcemaps for CSS, you'll need to pass the sourceMap property in the loader's options. If this is not passed, the loader will respect the setting for webpack source maps, set in devtool.

webpack.config.js

module.exports = {
  devtool: "source-map", // any "source-map"-like devtool is possible
  module: {
    rules: [
      {
        test: /\.styl$/,
        use: [
          "style-loader",
          {
            loader: "css-loader",
            options: {
              sourceMap: true,
            },
          },
          {
            loader: "stylus-loader",
            options: {
              sourceMap: true,
            },
          },
        ],
      },
    ],
  },
};

Using nib with stylus

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl$/,
        use: [
          {
            loader: "style-loader", // creates style nodes from JS strings
          },
          {
            loader: "css-loader", // translates CSS into CommonJS
          },
          {
            loader: "stylus-loader", // compiles Stylus to CSS
            options: {
              stylusOptions: {
                use: [require("nib")()],
                import: ["nib"],
              },
            },
          },
        ],
      },
    ],
  },
};

Import JSON files

Stylus does not provide resolving capabilities in the json() function. Therefore webpack resolver does not work for .json files. To handle this, use a stylus resolver.

index.styl

// Suppose the file is located here `node_modules/vars/vars.json`
json('vars.json')

@media queries-small
  body
    display nope

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl$/,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "stylus-loader",
            options: {
              stylusOptions: {
                // Specify the path. where to find files
                paths: ["node_modules/vars"],
              },
            },
          },
        ],
      },
    ],
  },
};

In production

Usually, it's recommended to extract the style sheets into a dedicated CSS file in production using the MiniCssExtractPlugin. This way your styles are not dependent on JavaScript.

webpack resolver

Webpack provides an advanced mechanism to resolve files. The stylus-loader applies the webpack resolver when processing queries. Thus you can import your Stylus modules directly from node_modules.

@import 'bootstrap-styl/bootstrap/index.styl';

Using ~ prefix is deprecated and can be removed from your code (we recommended), but we still support it for historical reasons.

Why you can removed it? The loader will first try to resolve @import/@require as relative, if it cannot be resolved, the loader will try to resolve @import/@require inside node_modules.

Just prepend them with a ~ which tells webpack to look up the modules.

@import "~bootstrap-styl/bootstrap/index.styl";

It's important to only prepend it with ~, because ~/ resolves to the home-directory, which is different.

Webpack needs to distinguish between bootstrap and ~bootstrap, because CSS and Stylus files have no special syntax for importing relative files.

Writing @import "file" is the same as @import "./file";

Stylus resolver

If you specify the paths option, modules will be searched in the given paths. This is the default Stylus behavior.

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.styl/,
        use: [
          {
            loader: "style-loader",
          },
          {
            loader: "css-loader",
          },
          {
            loader: "stylus-loader",
            options: {
              stylusOptions: {
                paths: [path.resolve(__dirname, "node_modules")],
              },
            },
          },
        ],
      },
    ],
  },
};

Extracting style sheets

Bundling CSS with webpack has some nice advantages like referencing images and fonts with hashed URLs or hot module replacement in development. In production, on the other hand, it's not a good idea to apply your style sheets depending on JS execution. Rendering may be delayed or even a FOUC might be visible. Thus it's often still better to have them as separate files in your final production build.

There are two possibilities to extract a style sheet from the bundle:

• extract-loader (simpler, but specialized on the css-loader's output)
• MiniCssExtractPlugin (more complex, but works in all use-cases)

Contributing

We welcome all contributions! If you're new here, please take a moment to review our contributing guidelines before submitting issues or pull requests.

CONTRIBUTING

License

MIT