Add SASS support

Author: fillaa

packages/react-scripts/config/webpack.config.dev.js

@@ -188,6 +188,7 @@ module.exports = {
           // "style" loader turns CSS into JS modules that inject <style> tags.
           // In production, we use a plugin to extract that CSS to a file, but
           // in development "style" loader enables hot editing of CSS.
+          // SASS/SCSS supported.
           {
             test: /\.css$/,
             use: [
@@ -220,6 +221,44 @@ module.exports = {
               },
             ],
           },
+          {
+            test: /\.scss$/,
+            use: [
+              require.resolve('style-loader'),
+              {
+                loader: require.resolve('css-loader'),
+                options: {
+                  importLoaders: 1,
+                },
+              },
+              {
+                loader: require.resolve('postcss-loader'),
+                options: {
+                  // Necessary for external CSS imports to work
+                  // https://github.com/facebookincubator/create-react-app/issues/2677
+                  ident: 'postcss',
+                  plugins: () => [
+                    require('postcss-flexbugs-fixes'),
+                    autoprefixer({
+                      browsers: [
+                        '>1%',
+                        'last 4 versions',
+                        'Firefox ESR',
+                        'not ie < 9', // React doesn't support IE8 anyway
+                      ],
+                      flexbox: 'no-2009',
+                    }),
+                  ],
+                },
+              },
+              {
+                loader: require.resolve('sass-loader'),
+                options: {
+                  importLoaders: 1,
+                },
+              },
+            ],
+          },
           // "file" loader makes sure those assets get served by WebpackDevServer.
           // When you `import` an asset, you get its (virtual) filename.
           // In production, they would get copied to the `build` folder.

packages/react-scripts/config/webpack.config.prod.js

@@ -200,6 +200,7 @@ module.exports = {
           // tags. If you use code splitting, however, any async bundles will still
           // use the "style" loader inside the async code so CSS from them won't be
           // in the main CSS file.
+          // SASS/SCSS supported.
           {
             test: /\.css$/,
             loader: ExtractTextPlugin.extract(
@@ -247,6 +248,59 @@ module.exports = {
             ),
             // Note: this won't work without `new ExtractTextPlugin()` in `plugins`.
           },
+          {
+            test: /\.scss$/,
+            loader: ExtractTextPlugin.extract(
+              Object.assign(
+                {
+                  fallback: {
+                    loader: require.resolve('style-loader'),
+                    options: {
+                      hmr: false,
+                    },
+                  },
+                  use: [
+                    {
+                      loader: require.resolve('css-loader'),
+                      options: {
+                        importLoaders: 1,
+                        minimize: true,
+                        sourceMap: shouldUseSourceMap,
+                      },
+                    },
+                    {
+                      loader: require.resolve('postcss-loader'),
+                      options: {
+                        // Necessary for external CSS imports to work
+                        // https://github.com/facebookincubator/create-react-app/issues/2677
+                        ident: 'postcss',
+                        plugins: () => [
+                          require('postcss-flexbugs-fixes'),
+                          autoprefixer({
+                            browsers: [
+                              '>1%',
+                              'last 4 versions',
+                              'Firefox ESR',
+                              'not ie < 9', // React doesn't support IE8 anyway
+                            ],
+                            flexbox: 'no-2009',
+                          }),
+                        ],
+                      },
+                    },
+                    {
+                      loader: require.resolve('sass-loader'),
+                      options: {
+                        importLoaders: 1,
+                      },
+                    },
+                  ],
+                },
+                extractTextPluginOptions
+              )
+            ),
+            // Note: this won't work without `new ExtractTextPlugin()` in `plugins`.
+          },
           // "file" loader makes sure assets end up in the `build` folder.
           // When you `import` an asset, you get its filename.
           // This loader doesn't use a "test" so it will catch all modules

packages/react-scripts/package.json

@@ -41,9 +41,10 @@
     "postcss-loader": "2.0.8",
     "promise": "8.0.1",
     "raf": "3.4.0",
-    "source-map-loader": "^0.2.1",
     "react-dev-utils": "^5.0.1",
     "resolve": "1.6.0",
+    "sass-loader": "^7.0.3",
+    "source-map-loader": "^0.2.1",
     "style-loader": "0.19.0",
     "sw-precache-webpack-plugin": "0.11.4",
     "ts-jest": "22.0.1",