Import CSS from "node_modules" in Webpack

If you are using too many things from one node_modules folder you can also create an alias by passing this following option

options: {
    url: false,
    includePaths: [
        // this one for using node_modules as a base folder
        path.resolve('node_modules'),
        // this one for using sass as the base folder
        path.resolve('node_modules/flag-icon-css/sass')
    ]
}

After the configuration, you can import as you were trying in your question.

I had a similar issue today. After all, all I had to do was to configure resolve in my webpack config file. I hope this will help somebody.

Webpack version I used:

"webpack": "^4.37.0",

In a webpack config file, the following should be configured:

module.exports = {
  resolve: {
    extensions: ['.json', '.js', '.jsx'],
    modules: ['node_modules'],
  },

or

module.exports = {
  resolve: {
    alias: {
      'some-library': path.resolve(__dirname, './node_modules/some-library'),
    }
  },

In a css file, we can access a library by a relative path from node_modules:

@import '~some-library/src/some-css-file';

You can import files relative to your project's root (resolving node_modules/ from the root folder) by prefixing with a tilde ~:

@import '~react-select/dist/react-datetime.css';

This is a poorly documented Webpack (a redundant phrase) convention, see https://github.com/webpack-contrib/css-loader/issues/12#issuecomment-41940311 and What does a `~` tilde in a CSS `url()` do?