How to import CSS files into webpack?

Question

According to the documentation, CSS file should just be imported.

I am just starting with webpack and tried to import a CSS file but I get a message about a module missing:

D:\Dropbox\dev\jekyll\blog>webpack --display-error-details
Hash: 0cabc1049cbcbdb8d134
Version: webpack 2.6.1
Time: 74ms
   Asset     Size  Chunks             Chunk Names
build.js  2.84 kB       0  [emitted]  main
   [0] ./webpack/entry.js 47 bytes {0} [built]

ERROR in ./webpack/entry.js
Module not found: Error: Can't resolve 'navbar.css' in 'D:\Dropbox\dev\jekyll\blog\webpack'
resolve 'navbar.css' in 'D:\Dropbox\dev\jekyll\blog\webpack'
  Parsed request is a module
  using description file: D:\Dropbox\dev\jekyll\blog\package.json (relative path: ./webpack)
    Field 'browser' doesn't contain a valid alias configuration
  after using description file: D:\Dropbox\dev\jekyll\blog\package.json (relative path: ./webpack)
    resolve as module
      D:\Dropbox\dev\jekyll\blog\webpack\node_modules doesn't exist or is not a directory
      D:\Dropbox\dev\jekyll\node_modules doesn't exist or is not a directory
      D:\Dropbox\dev\node_modules doesn't exist or is not a directory
      D:\Dropbox\node_modules doesn't exist or is not a directory
      D:\node_modules doesn't exist or is not a directory
      looking for modules in D:\Dropbox\dev\jekyll\blog\node_modules
        using description file: D:\Dropbox\dev\jekyll\blog\package.json (relative path: ./node_modules)
          Field 'browser' doesn't contain a valid alias configuration
        after using description file: D:\Dropbox\dev\jekyll\blog\package.json (relative path: ./node_modules)
          using description file: D:\Dropbox\dev\jekyll\blog\package.json (relative path: ./node_modules/navbar.css)
            as directory
              D:\Dropbox\dev\jekyll\blog\node_modules\navbar.css doesn't exist
            no extension
              Field 'browser' doesn't contain a valid alias configuration
              D:\Dropbox\dev\jekyll\blog\node_modules\navbar.css doesn't exist
            .js
              Field 'browser' doesn't contain a valid alias configuration
              D:\Dropbox\dev\jekyll\blog\node_modules\navbar.css.js doesn't exist
            .json
              Field 'browser' doesn't contain a valid alias configuration
              D:\Dropbox\dev\jekyll\blog\node_modules\navbar.css.json doesn't exist
[D:\Dropbox\dev\jekyll\blog\webpack\node_modules]
[D:\Dropbox\dev\jekyll\node_modules]
[D:\Dropbox\dev\node_modules]
[D:\Dropbox\node_modules]
[D:\node_modules]
[D:\Dropbox\dev\jekyll\blog\node_modules\navbar.css]
[D:\Dropbox\dev\jekyll\blog\node_modules\navbar.css]
[D:\Dropbox\dev\jekyll\blog\node_modules\navbar.css.js]
[D:\Dropbox\dev\jekyll\blog\node_modules\navbar.css.json]
 @ ./webpack/entry.js 1:0-21

webpack is ran against the following webpack.config.js:

const path = require('path');

module.exports = {
  entry: path.join(__dirname, 'webpack/entry.js'),
  output: {
    path: path.join(__dirname, 'dist'),
    filename: 'build.js'
  },
  module: {
    loaders: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
        exclude: /node_modules/
      }
    ],
    rules: [{
            test: /\.css$/,
            use: [ 'style-loader', 'css-loader' ]
        }]
  }
}

I initially thought (before using --display-error-details) that this was due to some problems with the path structure (specifically forward vs. backward slashes) but then moved navbar.css into the root of the folder webpack - same issue.

The detailed error shows that the CSS file is sought after in nodes_module (which is hunted down though all the directories tree). Why? How should I then import a file which is in webpack/static/css/myfile.css relative to the location of webpack.config.js?

Note: the same issue exists when trying require instead of import

Solution

You have to import them like any JavaScript module. That means, when the imported file is neither a relative path (starting with ../ or ./), nor an absolute path (starting with /), it is resolved as a module. By default webpack will look for modules in the node_modules directory (in the current directory and all parent directories). This is the same behaviour that Node.js uses.

To import webpack/static/css/myfile.css in webpack/entry.js you have to use a relative path.

import './static/css/myfile.css';

If you don't want to use a relative path, you can change the directories that webpack uses to find a module with the resolve.modules or you can use resolve.alias.

---

In your webpack config you also defined both module.rules and module.loaders. When webpack sees module.rules it ignores module.loaders completely, so your babel-loader wouldn't be used. You should only use module.rules.

module: {
  rules: [
    {
      test: /\.js$/,
      loader: 'babel-loader',
      exclude: /node_modules/
    },
    {
      test: /\.css$/,
      use: ['style-loader', 'css-loader']
    }
  ]
}