title: What is exactly the importLoaders option of css-loader in Webpack 4?
body: <p>I've started learning Webpack 4 since a month. Most things I wanted to do is working great but this <code>importLoaders</code> option of <code>css-loader</code> is still a mystery for me. Its official <a href="https://webpack.js.org/loaders/css-loader/#importloaders" rel="noreferrer">documentation</a> is poor and I haven't found any well explained writing about it.</p>
  
  <p>My use case is very close to the one presented in the documentation:</p>
  
  <pre><code>{
    test: /\.s?css$/,
    use: [
      ExtractCssChunks.loader,
      {
        loader: 'css-loader',
        options: {
          importLoaders: 2, // 0 =&gt; no loaders (default); 1 =&gt; postcss-loader; 2 =&gt; postcss-loader, sass-loader
          import: true, // is true by default, but should I use instead false here???
          url: false // let postcss do it
        }
      },
      'postcss-loader',
      'sass-loader'
    ]
  }
  </code></pre>
  
  <p>And my vendors.scss for example with different kind of imports:</p>
  
  <pre><code>@charset 'UTF-8';
  
  // Google fonts
  @import url('https://fonts.googleapis.com/css?family=Open+Sans:300,400,600,700|Dosis:200,400,500,600');
  
  //FontAwesome (from node_modules)
  @import "~@fortawesome/fontawesome-svg-core/styles";
  
  // Site theme
  @import "theme/index";
  </code></pre>
  
  <p>Basically I want <code>sass-loader</code> to do its usual job and <code>postcss</code> to do some manipulation with image files.</p>
  
  <p><strong>So when and why should I use 0/1/2/n for <code>importLoaders</code> option?</strong><br>
  How is it affected to my <code>@imports</code> above?  </p>
  
  <p>Could someone explain it to me more detailed like in the docs?<br>
  Thanks in advance.</p>