@rollup/plugin-inject

What is @rollup/plugin-inject?

@rollup/plugin-inject is a Rollup plugin that allows you to automatically inject variables or modules into your bundle. This can be useful for polyfilling global variables, injecting dependencies, or providing shims for certain environments.

What are @rollup/plugin-inject's main functionalities?

Injecting Global Variables

This feature allows you to inject global variables into your bundle. In this example, the `$` variable is automatically injected and mapped to the `jquery` module.

const inject = require('@rollup/plugin-inject');

module.exports = {
  input: 'src/main.js',
  output: {
    file: 'bundle.js',
    format: 'iife'
  },
  plugins: [
    inject({
      $: 'jquery'
    })
  ]
};

Injecting Multiple Variables

This feature allows you to inject multiple variables into your bundle. In this example, both `$` and `_` are injected and mapped to `jquery` and `lodash` respectively.

const inject = require('@rollup/plugin-inject');

module.exports = {
  input: 'src/main.js',
  output: {
    file: 'bundle.js',
    format: 'iife'
  },
  plugins: [
    inject({
      $: 'jquery',
      _: 'lodash'
    })
  ]
};

Injecting Custom Code

This feature allows you to inject custom code or modules into your bundle. In this example, `customVar` is injected and mapped to `src/customModule.js`.

const inject = require('@rollup/plugin-inject');

module.exports = {
  input: 'src/main.js',
  output: {
    file: 'bundle.js',
    format: 'iife'
  },
  plugins: [
    inject({
      include: '**/*.js',
      exclude: 'node_modules/**',
      modules: {
        customVar: 'src/customModule.js'
      }
    })
  ]
};

Other packages similar to @rollup/plugin-inject

babel-plugin-transform-define

babel-plugin-transform-define is a Babel plugin that allows you to inject global constants into your code. It is similar to @rollup/plugin-inject but is used within the Babel ecosystem. It is useful for defining environment variables and other constants at build time.

browserify-global-shim

browserify-global-shim is a Browserify plugin that allows you to replace global variables with require calls. It is similar to @rollup/plugin-inject but is used within the Browserify ecosystem. It is useful for shimming global variables and providing polyfills.

README

@rollup/plugin-inject

🍣 A Rollup plugin which scans modules for global variables and injects import statements where necessary.

Requirements

This plugin requires an LTS Node version (v14.0.0+) and Rollup v1.20.0+.

Install

Using npm:

npm install @rollup/plugin-inject --save-dev

Usage

Create a rollup.config.js configuration file and import the plugin:

import inject from '@rollup/plugin-inject';

export default {
  input: 'src/index.js',
  output: {
    dir: 'output',
    format: 'cjs'
  },
  plugins: [
    inject({
      Promise: ['es6-promise', 'Promise']
    })
  ]
};

Then call rollup either via the CLI or the API.

This configuration above will scan all your files for global Promise usage and plugin will add import to desired module (import { Promise } from 'es6-promise' in this case).

Examples:

{
  // import { Promise } from 'es6-promise'
  Promise: [ 'es6-promise', 'Promise' ],

  // import { Promise as P } from 'es6-promise'
  P: [ 'es6-promise', 'Promise' ],

  // import $ from 'jquery'
  $: 'jquery',

  // import * as fs from 'fs'
  fs: [ 'fs', '*' ],

  // use a local module instead of a third-party one
  'Object.assign': path.resolve( 'src/helpers/object-assign.js' ),
}

Typically, @rollup/plugin-inject should be placed in plugins before other plugins so that they may apply optimizations, such as dead code removal.

Options

In addition to the properties and values specified for injecting, users may also specify the options below.

exclude

Type: String | Array[...String]
Default: null

A picomatch pattern, or array of patterns, which specifies the files in the build the plugin should ignore. By default no files are ignored.

include

Type: String | Array[...String]
Default: null

A picomatch pattern, or array of patterns, which specifies the files in the build the plugin should operate on. By default all files are targeted.

Meta

CONTRIBUTING

LICENSE (MIT)