npm-install-webpack-plugin

4.0.5 verified Sat Apr 25 auth: no javascript maintenance

Webpack plugin that automatically installs and saves missing npm dependencies during development. Current stable version is 4.0.5 (last released August 2017). It intercepts import/require calls in webpack builds and runs npm install for any missing modules, supporting both ES5 and ES6, CSS imports, namespaced packages, webpack loaders, and .babelrc plugins/presets. Unlike manual npm install workflows, this plugin aims to eliminate the cycle of stopping a dev server to install dependencies. However, it only supports npm (not yarn), relies on webpack 1–3, and is no longer actively maintained.

Common errors

error Error: Cannot find module 'npm-install-webpack-plugin' ↓

cause Plugin not installed in devDependencies.

fix

npm install --save-dev npm-install-webpack-plugin

error TypeError: NpmInstallPlugin is not a constructor ↓

cause Wrong import style: using named import instead of default import.

fix

Use const NpmInstallPlugin = require('npm-install-webpack-plugin') or import NpmInstallPlugin from 'npm-install-webpack-plugin'

error npm-install-webpack-plugin: You must use webpack >= 1.12.0 ↓

cause Webpack version too old (<1.12).

fix

Upgrade webpack to at least 1.12.0 or use an older version of the plugin.

Warnings

deprecated Package is no longer actively maintained. Last release 2017, webpack 4+ not supported. ↓

fix Consider alternatives like webpack-merge-and-include-globally or manual npm install workflows.

breaking Only supports webpack 1–3. Using webpack 4 or 5 will cause errors. ↓

fix Downgrade webpack or use a different plugin.

gotcha npm client only – does not support yarn or pnpm. The `npm` option expects a string like 'tnpm' but not 'yarn'. ↓

fix Use npm or a wrapper that emulates npm CLI.

gotcha May corrupt node_modules if npm install fails mid-flight – no rollback. ↓

fix Lock dependency versions or use a version control system to restore node_modules.

breaking Changes to `dev` option signature in v4: it now accepts a function or boolean, not a string. ↓

fix Update config: new NpmInstallPlugin({ dev: false }) or a function.

Install

npm install npm-install-webpack-plugin

yarn add npm-install-webpack-plugin

pnpm add npm-install-webpack-plugin

Imports

default
wrong
```
const NpmInstallPlugin = require('npm-install-webpack-plugin')
```
correct
```
import NpmInstallPlugin from 'npm-install-webpack-plugin'
```
ESM default import works if your project supports ES modules; CommonJS require is also valid and commonly used.

NpmInstallPlugin

wrong

import { NpmInstallPlugin } from 'npm-install-webpack-plugin'

correct

const NpmInstallPlugin = require('npm-install-webpack-plugin')

The module exports a default class, not a named export; named import will be undefined.

NpmInstallPlugin
wrong
```
plugins: [new require('npm-install-webpack-plugin')()]
```
correct
```
plugins: [new NpmInstallPlugin()]
```
Instantiate with `new` – the plugin is a class constructor, not a factory function.

Quickstart

Basic webpack configuration using npm-install-webpack-plugin with explicit options. Automatically installs missing dependencies when you import them.

// webpack.config.js
const NpmInstallPlugin = require('npm-install-webpack-plugin');

module.exports = {
  entry: './src/index.js',
  output: { filename: 'bundle.js' },
  plugins: [
    new NpmInstallPlugin({
      dev: false,
      peerDependencies: true,
      quiet: false,
      npm: 'npm'
    })
  ]
};