code: function prependTildesToImports(styles) {
    styles.eachAtRule(function (atRule) {
      if (atRule.name !== 'import')
        return;
  
      var stripped = stripQuotes(unwrapUrl(atRule.params));
      if (stripped[0] !== '.' && stripped[0] !== '~' && stripped[0] !== '/') {
        atRule.params = '"~' + stripped + '"';
      }
  
    });
  }
docs: prepend a tilde to css module imports
  
  webpack's css-loader [treats css imports as relative paths][url-to-req], not
  modules. the easiest way i've found to correct this prepending a `~` to each
  import to force webpack to use it's full module lookup machinery.
  
  [url-to-req]: https://github.com/webpack/css-loader/blob/7b50d4f569adcaf5bf185180c15435bde03f4de7/index.js#L37