feat(build): minify/optimize component stylesheets (#4259)

Author: clydin

package.json

@@ -48,6 +48,7 @@
     "chalk": "^1.1.3",
     "common-tags": "^1.3.1",
     "css-loader": "^0.26.1",
+    "cssnano": "^3.10.0",
     "debug": "^2.1.3",
     "denodeify": "^1.2.1",
     "diff": "^2.2.2",
@@ -81,7 +82,6 @@
     "opn": "4.0.1",
     "ora": "^0.2.0",
     "portfinder": "1.0.9",
-    "postcss-discard-comments": "^2.0.4",
     "postcss-loader": "^0.9.1",
     "raw-loader": "^0.5.1",
     "reflect-metadata": "^0.1.8",

packages/angular-cli/models/webpack-configs/production.ts

@@ -13,7 +13,6 @@ export const getProdConfig = function (wco: WebpackConfigOptions) {
       new webpack.DefinePlugin({
         'process.env.NODE_ENV': JSON.stringify('production')
       }),
-      new webpack.LoaderOptionsPlugin({ minimize: true }),
       new webpack.optimize.UglifyJsPlugin(<any>{
         mangle: { screw_ie8: true },
         compress: { screw_ie8: true, warnings: buildOptions.verbose },

packages/angular-cli/models/webpack-configs/styles.ts

@@ -6,7 +6,7 @@ import {
 import { extraEntryParser, getOutputHashFormat } from './utils';
 import { WebpackConfigOptions } from '../webpack-config';
 
-const postcssDiscardComments = require('postcss-discard-comments');
+const cssnano = require('cssnano');
 const autoprefixer = require('autoprefixer');
 const ExtractTextPlugin = require('extract-text-webpack-plugin');
 
@@ -38,9 +38,10 @@ export function getStylesConfig(wco: WebpackConfigOptions) {
   // https://github.com/webpack-contrib/style-loader#recommended-configuration
   const cssSourceMap = buildOptions.extractCss && buildOptions.sourcemap;
 
-  // discard comments in production
+  // minify/optimize css in production
+  // autoprefixer is always run separately so disable here
   const extraPostCssPlugins = buildOptions.target === 'production'
-    ? [postcssDiscardComments]
+    ? [cssnano({ safe: true, autoprefixer: false })]
     : [];
 
   // determine hashing format

packages/angular-cli/package.json

@@ -38,6 +38,7 @@
     "chalk": "^1.1.3",
     "common-tags": "^1.3.1",
     "css-loader": "^0.26.1",
+    "cssnano": "^3.10.0",
     "debug": "^2.1.3",
     "denodeify": "^1.2.1",
     "diff": "^2.2.2",
@@ -68,7 +69,6 @@
     "opn": "4.0.1",
     "ora": "^0.2.0",
     "portfinder": "1.0.9",
-    "postcss-discard-comments": "^2.0.4",
     "postcss-loader": "^0.9.1",
     "raw-loader": "^0.5.1",
     "remap-istanbul": "^0.6.4",