feat(@angular/cli): use cache and parallelization for build-optimizer

Author: filipesilva

package-lock.json

@@ -46,6 +46,7 @@
     "@angular-devkit/schematics": "~0.0.51",
     "@schematics/angular": "~0.1.16",
     "autoprefixer": "^7.2.3",
+    "cache-loader": "^1.2.0",
     "chalk": "~2.2.0",
     "circular-dependency-plugin": "^4.2.1",
     "clean-css": "^4.1.9",
@@ -114,8 +115,8 @@
     "@types/fs-extra": "^4.0.0",
     "@types/glob": "^5.0.29",
     "@types/jasmine": "2.5.45",
-    "@types/lodash": "~4.14.50",
     "@types/loader-utils": "^1.1.0",
+    "@types/lodash": "~4.14.50",
     "@types/minimist": "^1.2.0",
     "@types/mock-fs": "^3.6.30",
     "@types/node": "^6.0.84",
@@ -128,6 +129,7 @@
     "dtsgenerator": "^0.9.1",
     "eslint": "^3.11.0",
     "express": "^4.14.0",
+    "happypack": "^4.0.0",
     "jasmine": "^2.6.0",
     "jasmine-spec-reporter": "^4.1.0",
     "license-checker": "^15.0.0",

package.json

@@ -11,6 +11,8 @@ import { ScriptsWebpackPlugin } from '../../plugins/scripts-webpack-plugin';
 const ProgressPlugin = require('webpack/lib/ProgressPlugin');
 const CircularDependencyPlugin = require('circular-dependency-plugin');
 const SilentError = require('silent-error');
+const HappyPack = require('happypack');
+const resolve = require('resolve');
 
 /**
  * Enumerate loaders and their dependencies from this file to let the dependency validator
@@ -104,8 +106,8 @@ export function getCommonConfig(wco: WebpackConfigOptions) {
 
         if (!asset.allowOutsideOutDir) {
           const message = 'An asset cannot be written to a location outside of the output path. '
-                        + 'You can override this message by setting the `allowOutsideOutDir` '
-                        + 'property on the asset to true in the CLI configuration.';
+            + 'You can override this message by setting the `allowOutsideOutDir` '
+            + 'property on the asset to true in the CLI configuration.';
           throw new SilentError(message);
         }
       }
@@ -163,13 +165,28 @@ export function getCommonConfig(wco: WebpackConfigOptions) {
   }
 
   if (buildOptions.buildOptimizer) {
+    // Set the cache directory to the Build Optimizer dir, so that package updates will delete it.
+    const buildOptimizerDir = path.dirname(
+      resolve.sync('@angular-devkit/build-optimizer', { basedir: projectRoot }));
+    const cacheDirectory = path.resolve(buildOptimizerDir, './.cache/');
+
     extraRules.push({
       test: /\.js$/,
-      use: [{
-        loader: '@angular-devkit/build-optimizer/webpack-loader',
-        options: { sourceMap: buildOptions.sourcemaps }
-      }]
+      use: ['happypack/loader'],
     });
+    extraPlugins.push(new HappyPack({
+      verbose: false,
+      loaders: [
+        {
+          loader: 'cache-loader',
+          options: { cacheDirectory }
+        },
+        {
+          loader: '@angular-devkit/build-optimizer/webpack-loader',
+          options: { sourceMap: buildOptions.sourcemaps }
+        }
+      ],
+    }));
   }
 
   if (buildOptions.namedChunks) {