gatsby-plugin-less

Provides drop-in support for Less stylesheets

Install

npm install gatsby-plugin-less

How to use

  1. Include the plugin in your gatsby-config.js file.
  2. Write your stylesheets in Less and require or import them as normal.
// in gatsby-config.js
plugins: [`gatsby-plugin-less`]

If you need to pass options to the Less loader use the loaderOptions and to Less use lessOptions object; see less-loader for all available options.

// in gatsby-config.js
plugins: [
  {
    resolve: `gatsby-plugin-less`,
    options: {
      loaderOptions: {
        appendData: `@env: ${process.env.NODE_ENV};`,
      },
      lessOptions: {
        strictMath: true,
        plugins: [new CleanCSSPlugin({ advanced: true })],
      },
    },
  },
]

If you need to override the default options passed into css-loader Note: Gatsby is using css-loader@^5.0.0.

// in gatsby-config.js
plugins: [
  {
    resolve: `gatsby-plugin-less`,
    options: {
      cssLoaderOptions: {
        camelCase: false,
      },
    },
  },
]

With CSS Modules

Using CSS modules requires no additional configuration. Simply prepend .module to the extension. For example: app.less -> app.module.less. Any file with the module extension will use CSS modules. CSS modules are imported as ES Modules to support treeshaking. You’ll need to import styles as: import { yourClassName, anotherClassName } from './app.module.less'.

PostCSS plugins

PostCSS is also included to handle some default optimizations like autoprefixing and common cross-browser flexbox bugs. Normally you don’t need to think about it, but if you’d prefer to add additional postprocessing to your Less output you can specify plugins in the plugin options

// in gatsby-config.js
plugins: [
  {
    resolve: `gatsby-plugin-less`,
    options: {
      postCssPlugins: [somePostCssPlugin()],
    },
  },
]

Breaking changes history

v4.0.0

  • less-loader options now possible with the object loaderOptions.
  • less options moved to the object lessOptions because of api change on less-loader v6.

v2.0.0

  • less is moved to a peer dependency. Installing the package alongside gatsby-plugin-less is now required. Use npm install less
  • support Gatsby v2 only
  • theme option has been removed. You can pass configuration object to less-loader:
plugins: [
  {
    resolve: `gatsby-plugin-less`,
    options: {
-      theme: {
-        "text-color": `#fff`,
-      }
+      modifyVars: {
+        "text-color": `#fff`,
+      }
    },
  },
]
plugins: [
  {
    resolve: `gatsby-plugin-less`,
    options: {
-      theme: `./src/theme.js`,
+      modifyVars: require(`./src/theme.js`),
    },
  },
]