fix(@angular-devkit/build-angular): change css optimizer from clean-css with cssnano

Closes #16123 and closes #13854

Author: alan-agius4

package.json

@@ -93,8 +93,8 @@
     "@types/babel__core": "7.1.3",
     "@types/browserslist": "^4.4.0",
     "@types/caniuse-lite": "^1.0.0",
-    "@types/clean-css": "^4.2.1",
     "@types/copy-webpack-plugin": "^5.0.0",
+    "@types/cssnano": "^4.0.0",
     "@types/express": "^4.16.0",
     "@types/find-cache-dir": "^2.0.0",
     "@types/glob": "^7.0.0",

packages/angular_devkit/build_angular/package.json

@@ -21,8 +21,8 @@
     "browserslist": "4.8.3",
     "cacache": "13.0.1",
     "caniuse-lite": "1.0.30001020",
+    "cssnano": "4.1.10",
     "circular-dependency-plugin": "5.2.0",
-    "clean-css": "4.2.1",
     "coverage-istanbul-loader": "2.0.3",
     "copy-webpack-plugin": "5.1.1",
     "core-js": "3.6.2",

packages/angular_devkit/build_angular/src/angular-cli-files/models/webpack-configs/common.ts

@@ -31,8 +31,8 @@ import { BuildBrowserFeatures } from '../../../utils';
 import { findCachePath } from '../../../utils/cache-path';
 import { cachingDisabled, manglingDisabled } from '../../../utils/environment-options';
 import { BundleBudgetPlugin } from '../../plugins/bundle-budget';
-import { CleanCssWebpackPlugin } from '../../plugins/cleancss-webpack-plugin';
 import { NamedLazyChunksPlugin } from '../../plugins/named-chunks-plugin';
+import { OptimizeCssWebpackPlugin } from '../../plugins/optimize-css-webpack-plugin';
 import { ScriptsWebpackPlugin } from '../../plugins/scripts-webpack-plugin';
 import { WebpackRollupLoader } from '../../plugins/webpack';
 import { findAllNodeModules, findUp } from '../../utilities/find-up';
@@ -363,7 +363,7 @@ export function getCommonConfig(wco: WebpackConfigOptions): Configuration {
   const extraMinimizers = [];
   if (stylesOptimization) {
     extraMinimizers.push(
-      new CleanCssWebpackPlugin({
+      new OptimizeCssWebpackPlugin({
         sourceMap: stylesSourceMap,
         // component styles retain their original file name
         test: file => /\.(?:css|scss|sass|less|styl)$/.test(file),

packages/angular_devkit/build_angular/src/angular-cli-files/plugins/cleancss-webpack-plugin.ts renamed to packages/angular_devkit/build_angular/src/angular-cli-files/plugins/optimize-css-webpack-plugin.ts

@@ -5,11 +5,12 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
-import * as CleanCSS from 'clean-css';
+import * as cssNano from 'cssnano';
+import { ProcessOptions, Result } from 'postcss';
 import { Compiler, compilation } from 'webpack';
 import { RawSource, Source, SourceMapSource } from 'webpack-sources';
 
-export interface CleanCssWebpackPluginOptions {
+export interface OptimizeCssWebpackPluginOptions {
   sourceMap: boolean;
   test: (file: string) => boolean;
 }
@@ -22,19 +23,19 @@ function hook(
   ) => Promise<void | void[]>,
 ) {
   compiler.hooks.compilation.tap(
-    'cleancss-webpack-plugin',
+    'optimize-css-webpack-plugin',
     (compilation: compilation.Compilation) => {
-      compilation.hooks.optimizeChunkAssets.tapPromise('cleancss-webpack-plugin', chunks =>
+      compilation.hooks.optimizeChunkAssets.tapPromise('optimize-css-webpack-plugin', chunks =>
         action(compilation, chunks),
       );
     },
   );
 }
 
-export class CleanCssWebpackPlugin {
-  private readonly _options: CleanCssWebpackPluginOptions;
+export class OptimizeCssWebpackPlugin {
+  private readonly _options: OptimizeCssWebpackPluginOptions;
 
-  constructor(options: Partial<CleanCssWebpackPluginOptions>) {
+  constructor(options: Partial<OptimizeCssWebpackPluginOptions>) {
     this._options = {
       sourceMap: false,
       test: file => file.endsWith('.css'),
@@ -44,21 +45,6 @@ export class CleanCssWebpackPlugin {
 
   apply(compiler: Compiler): void {
     hook(compiler, (compilation: compilation.Compilation, chunks: compilation.Chunk[]) => {
-      const cleancss = new CleanCSS({
-        compatibility: 'ie9',
-        level: {
-          2: {
-            skipProperties: [
-              'transition', // Fixes #12408
-              'font', // Fixes #9648
-            ],
-          },
-        },
-        inline: false,
-        returnPromise: true,
-        sourceMap: this._options.sourceMap,
-      });
-
       const files: string[] = [...compilation.additionalChunkAssets];
 
       chunks.forEach(chunk => {
@@ -90,37 +76,40 @@ export class CleanCssWebpackPlugin {
             return;
           }
 
-          const output = await cleancss.minify(content, map);
-
-          let hasWarnings = false;
-          if (output.warnings && output.warnings.length > 0) {
-            compilation.warnings.push(...output.warnings);
-            hasWarnings = true;
-          }
-
-          if (output.errors && output.errors.length > 0) {
-            output.errors.forEach((error: string) => compilation.errors.push(new Error(error)));
-
-            return;
-          }
-
-          // generally means invalid syntax so bail
-          if (hasWarnings && output.stats.minifiedSize === 0) {
-            return;
+          const cssNanoOptions: cssNano.CssNanoOptions = {
+            preset: 'default',
+          };
+
+          const postCssOptions: ProcessOptions = {
+            from: file,
+            map: map && { annotation: false, prev: map },
+          };
+
+          const output = await new Promise<Result>((resolve, reject) => {
+            // the last parameter is not in the typings
+            // tslint:disable-next-line: no-any
+            (cssNano.process as any)(content, postCssOptions, cssNanoOptions)
+              .then(resolve)
+              .catch(reject);
+          });
+
+          const warnings = output.warnings();
+          if (warnings.length) {
+            compilation.warnings.push(...warnings.map(({ text }) => text));
           }
 
           let newSource;
-          if (output.sourceMap) {
+          if (output.map) {
             newSource = new SourceMapSource(
-              output.styles,
+              output.css,
               file,
               // tslint:disable-next-line: no-any
-              output.sourceMap.toString() as any,
+              output.map.toString() as any,
               content,
               map,
             );
           } else {
-            newSource = new RawSource(output.styles);
+            newSource = new RawSource(output.css);
           }
 
           compilation.assets[file] = newSource;

packages/angular_devkit/build_angular/src/angular-cli-files/plugins/webpack.ts

@@ -8,7 +8,7 @@
 
 // Exports the webpack plugins we use internally.
 export { AnyComponentStyleBudgetChecker } from './any-component-style-budget-checker';
-export { CleanCssWebpackPlugin, CleanCssWebpackPluginOptions } from './cleancss-webpack-plugin';
+export { OptimizeCssWebpackPlugin, OptimizeCssWebpackPluginOptions } from './optimize-css-webpack-plugin';
 export { BundleBudgetPlugin, BundleBudgetPluginOptions } from './bundle-budget';
 export { ScriptsWebpackPlugin, ScriptsWebpackPluginOptions } from './scripts-webpack-plugin';
 export { SuppressExtractedTextChunksWebpackPlugin } from './suppress-entry-chunks-webpack-plugin';

packages/angular_devkit/build_angular/test/browser/aot_spec_large.ts

@@ -40,30 +40,6 @@ describe('Browser Builder AOT', () => {
     await run.stop();
   });
 
-  it('shows warnings for component styles', async () => {
-    const overrides = {
-      aot: true,
-      optimization: true,
-    };
-
-    host.writeMultipleFiles({
-      'src/app/app.component.css': `
-        .foo { color: white; padding: 1px; };
-        .buz { color: white; padding: 2px; };
-      `,
-    });
-
-    const logger = new logging.Logger('');
-    const logs: string[] = [];
-    logger.subscribe(e => logs.push(e.message));
-
-    const run = await architect.scheduleTarget(targetSpec, overrides, { logger });
-    const output = await run.result;
-    expect(output.success).toBe(true);
-    expect(logs.join()).toContain('WARNING in Invalid selector');
-    await run.stop();
-  });
-
   it('shows error when component stylesheet contains SCSS syntax error', async () => {
     const overrides = {
       aot: true,

packages/angular_devkit/build_angular/test/browser/styles_spec_large.ts

@@ -585,23 +585,4 @@ describe('Browser Builder styles', () => {
     const { output } = await browserBuild(architect, host, target, overrides);
     expect(output.success).toBe(true);
   });
-
-  it('supports font names with spaces', async () => {
-    host.writeMultipleFiles({
-      'src/styles.css': `
-        body {
-          font: 10px "Font Awesome";
-        }
-      `,
-    });
-
-    const overrides = { extractCss: true, optimization: true };
-    const logger = new logging.Logger('font-name-spaces');
-    const logs: string[] = [];
-    logger.subscribe(e => logs.push(e.message));
-
-    const { output } = await browserBuild(architect, host, target, overrides, { logger });
-    expect(output.success).toBe(true);
-    expect(logs.join()).not.toContain('WARNING in Invalid font values ');
-  });
 });