npm install --save @types/optimize-css-assets-webpack-plugin
This package contains type definitions for optimize-css-assets-webpack-plugin (http://github.com/nmfr/optimize-css-assets-webpack-plugin).
Files were exported from https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/optimize-css-assets-webpack-plugin.
These definitions were written by Armando Meziat, and Spencer Miskoviak.