npm-install-webpack-plugin

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 However, it only supports npm (not yarn), relies on webpack 1–3, and is no longer actively maintained.