Moving minification options

The previous spot is an outdated spot anyways, and it caused an edge-case bug with
resolution of some SASS paths: symfony/demo#586

Author: weaverryan

lib/config-generator.js

@@ -100,7 +100,7 @@ class ConfigGenerator {
     buildRulesConfig() {
         const cssLoaders = [
             {
-                loader: 'css-loader' + this.getSourceMapOption(),
+                loader: 'css-loader' + this.getSourceMapOption()+(this.webpackConfig.isProduction() ? '?minimize=1' : ''),
             },
         ];
         if (this.webpackConfig.usePostCssLoader) {
@@ -292,7 +292,6 @@ class ConfigGenerator {
          * https://github.com/jtangelder/sass-loader/issues/285
          */
         plugins.push(new webpack.LoaderOptionsPlugin({
-            minimize: this.webpackConfig.isProduction(),
             debug: !this.webpackConfig.isProduction(),
             options: {
                 context: this.webpackConfig.getContext(),

test/functional.js

@@ -414,13 +414,19 @@ describe('Functional tests using webpack', function() {
             const config = createWebpackConfig('www/build', 'production');
             config.setPublicPath('/build');
             config.addEntry('main', ['./js/no_require']);
+            config.addEntry('styles', './css/h1_style.css');
 
             testSetup.runWebpack(config, (webpackAssert) => {
                 // the comment should not live in the file
                 webpackAssert.assertOutputFileDoesNotContain(
                     'main.js',
                     '// comments in no_require.js'
                 );
+                // extra spaces should not live in the CSS file
+                webpackAssert.assertOutputFileDoesNotContain(
+                    'styles.css',
+                    '    font-size: 50px;'
+                );
 
                 done();
             });