when I use CSS-loader to package CSS, but the CSS modules object return {}. I think I use the right configuration。 here is my WEBPACK

          {
            test: /\.css$/,
            use: [ 'style-loader', 
            {
                loader: "css-loader",
                options: {
                    modules: true
                }
            }]
          }

and I create a index.css

    //index.css
      @import url("./test.css");
      @import url("./fonts.css");

then I use it in index.js

    import  stycss from './index.css';
    console.log(stycss);

but the CSS modules object is returning {}, why? how to fix it?