rollup-plugin-less-modules

0.1.11 verified Mon Apr 27 auth: no javascript maintenance

A Rollup plugin that compiles imported LESS files into CSS during bundling. Version 0.1.11 is the latest stable release (no update in several years). Designed for component-based architectures like Angular that need style encapsulation. Alternatives include rollup-plugin-postcss or rollup-plugin-styles; this plugin is lighter but limited to LESS only and lacks modern PostCSS features. It supports source maps, minification via clean-css, and optional separate CSS output file. The repository is archived (not actively maintained).

Common errors

error Error: Could not find module 'rollup-plugin-less-modules' from '...' ↓

cause The package is not installed or is missing from node_modules.

fix

Run npm install --save-dev rollup-plugin-less-modules.

error TypeError: lessModules is not a function ↓

cause Using require() in an ESM-only package, or incorrect import syntax.

fix

Use ES module import: import lessModules from 'rollup-plugin-less-modules';.

error Error: The `output` option is not supported in rollup-plugin-less-modules v0.1.x. Use separate output if needed. ↓

cause Using output configuration from Rollup plugin incorrectly.

fix

Pass output as a plugin option, not in Rollup's output config.

Warnings

breaking The plugin does not work with Rollup >= 2.0 due to the removal of the bundle.transform hook. ↓

fix Use an alternative plugin like rollup-plugin-postcss.

breaking Default export changed from `lessModules` to `default` export in v0.1.0. ↓

fix Update imports: use `import lessModules from 'rollup-plugin-less-modules';`.

deprecated The `options.sourceMap` property is deprecated; use `sourcemap` at top-level options instead. ↓

fix Pass `sourcemap: true|false|'inline'` directly to the plugin.

gotcha Source maps may have incorrect file paths if `options.filename` is not set in Less options. ↓

fix Set `options.filename` relative to project root.

Install

npm install rollup-plugin-less-modules

yarn add rollup-plugin-less-modules

pnpm add rollup-plugin-less-modules

Imports

default

wrong

const lessModules = require('rollup-plugin-less-modules');

correct

import lessModules from 'rollup-plugin-less-modules';

Package is ESM-only. Using require() will not work.

lessModules

wrong

import lessModules from 'rollup-plugin-less-modules';

correct

import { lessModules } from 'rollup-plugin-less-modules';

Correct named import is actually the default export; there is no named export 'lessModules'.

sourceMap
wrong
```
import * as lessModule from './index.less';
```
correct
```
import style, { sourceMap } from './index.less';
```
The plugin enables default export (CSS string) and named export 'sourceMap' from .less files. Using namespace import breaks the naming convention.

Quickstart

Configures Rollup to compile imported LESS files and output a separate CSS bundle with inline source maps.

import { rollup } from 'rollup';
import lessModules from 'rollup-plugin-less-modules';

rollup({
    input: 'src/index.js',
    output: {
        file: 'dist/bundle.js',
        format: 'es'
    },
    plugins: [
        lessModules({
            output: 'dist/styles.css',
            sourcemap: 'inline'
        })
    ]
});