rolldown-plugin-sourcemaps

Rolldown plugin for loading files with existing source maps from sourceMappingURL comments.

Why?

• You consume external modules (from node_modules) with bundled source maps
• You want accurate stack traces pointing to original source code
• You need to chain source maps from pre-compiled dependencies

Installation

npm install rolldown-plugin-sourcemaps --save-dev
# or
pnpm add rolldown-plugin-sourcemaps -D

Usage

With Vite (Rolldown)

import sourcemaps from 'rolldown-plugin-sourcemaps';
import { defineConfig } from 'vite';

export default defineConfig({
  build: {
    sourcemap: true,
    rollupOptions: {
      plugins: [sourcemaps()]
    }
  }
});

With Rolldown directly

import sourcemaps from 'rolldown-plugin-sourcemaps';

export default {
  input: 'src/index.js',
  plugins: [sourcemaps()],
  output: {
    sourcemap: true,
    file: 'dist/bundle.js',
  },
};

Options

include

Type: string | RegExp | (string | RegExp)[]

Default: /[/\\]node_modules[/\\]/ (only processes files in node_modules)

Files to include for source map processing. By default, only files in node_modules are processed since that's where pre-compiled source maps typically exist.

// Process all files
sourcemaps({ include: /./ })

// Only process specific packages
sourcemaps({ include: /[/\\]node_modules[/\\]@myorg[/\\]/ })

exclude

Type: string | RegExp | (string | RegExp)[]

Default: undefined

Files to exclude from source map processing.

// Exclude specific packages
sourcemaps({ exclude: /[/\\]node_modules[/\\]some-large-package[/\\]/ })

Performance

This plugin is optimized for performance:

• Targeted processing: Only processes node_modules by default (where pre-compiled source maps exist)
• Fast detection: Uses simple string matching before regex parsing
• Parallel I/O: Resolves multiple source files in parallel
• Early termination: Skips unnecessary work when sourcesContent already exists

License

MIT

Credits

This project is a fork and modernization for Rolldown of the original work by:

• Max Davidson - Creator of rollup-plugin-sourcemaps
• Kudakwashe Mupeni - Maintainer of rollup-plugin-sourcemaps2

Inspired by webpack/source-map-loader.