Rollup Plugin Peer Deps External

Automatically externalize peerDependencies in a rollup bundle. Also optionally externalize dependencies in a rollup bundle.

Motivation

When bundling a library using rollup, we generally want to keep from including peerDependencies since they are expected to be provided by the consumer of the library. By excluding these dependencies, we keep bundle size down and avoid bundling duplicate dependencies.

We can achieve this using the rollup external configuration option, providing it a list of the peer dependencies to exclude from the bundle. This plugin automates the process, automatically adding a library's peerDependencies to the external configuration.

Module paths

This plugin is compatible with module path format applied by, for example, babel-plugin-lodash. For any module name in peerDependencies, all paths beginning with that module name will also be added to external.

E.g.: If lodash is in peerDependencies, an import of lodash/map would be added to externals.

Installation

npm install --save-dev rollup-plugin-peer-deps-external

Usage

// Add to plugins array in rollup.config.js
import peerDepsExternal from 'rollup-plugin-peer-deps-external';

export default {
  plugins: [
    // Preferably set as first plugin.
    peerDepsExternal(),
  ],
}

Options

packageJsonPath

If your package.json is not in the current working directory you can specify the path to the file

// Add to plugins array in rollup.config.js
import peerDepsExternal from 'rollup-plugin-peer-deps-external';

export default {
  plugins: [
    // Preferably set as first plugin.
    peerDepsExternal({
      packageJsonPath: 'my/folder/package.json'
    }),
  ],
}

includeDependencies

Sometimes it's necessary to include a package as a direct dependency instead of a peer dependency. This can happen if your package has a very specific requirement on the dependency and cannot accecpt another version. In this case set includeDependencies to true and all of your packages dependencies will also be included as externals

// Add to plugins array in rollup.config.js
import peerDepsExternal from 'rollup-plugin-peer-deps-external';

export default {
  plugins: [
    // Preferably set as first plugin.
    peerDepsExternal({
      includeDependencies: true,
    }),
  ],
}