feat(builders): support service worker generation with prerendering

Closes: angular#1505

Author: alan-agius4

modules/builders/BUILD.bazel

@@ -57,6 +57,7 @@ jasmine_node_test(
         "@npm//@angular/compiler",
         "@npm//@angular/platform-browser",
         "@npm//@angular/platform-browser-dynamic",
+        "@npm//@angular/service-worker",
         "@npm//@types/node",
         "@npm//browser-sync",
         "@npm//express",

modules/builders/src/prerender/index.spec.ts

@@ -7,7 +7,7 @@
  */
 
 import { Architect } from '@angular-devkit/architect';
-import { join, virtualFs } from '@angular-devkit/core';
+import { join, normalize, virtualFs } from '@angular-devkit/core';
 import { createArchitect, host, outputPathBrowser } from '../../testing/utils';
 
 describe('Prerender Builder', () => {
@@ -159,4 +159,38 @@ describe('Prerender Builder', () => {
 
     await run.stop();
   });
+
+  it('should generate service-worker', async () => {
+    const manifest = {
+      index: '/index.html',
+      assetGroups: [
+        {
+          name: 'app',
+          installMode: 'prefetch',
+          resources: {
+            files: [
+              '/index.html',
+            ],
+          },
+        },
+      ],
+    };
+
+    host.writeMultipleFiles({
+      'ngsw-config.json': JSON.stringify(manifest),
+    });
+
+    const run = await architect.scheduleTarget(target, { routes: ['foo'], browserTarget: 'app:build:sw' });
+    const output = await run.result;
+    expect(output.success).toBe(true);
+
+    const content = virtualFs.fileBufferToString(
+      host.scopedSync().read(join(outputPathBrowser, 'foo/index.html'))
+    );
+
+    expect(content).toContain('foo works!');
+    expect(content).toContain('This page was prerendered with Angular Universal');
+    expect(host.scopedSync().exists(normalize('dist/app/browser/ngsw.json'))).toBeTrue();
+    await run.stop();
+  });
 });

modules/builders/src/prerender/index.ts

@@ -8,6 +8,9 @@
 
 import { BuilderContext, BuilderOutput, createBuilder, targetFromTargetString } from '@angular-devkit/architect';
 import { BrowserBuilderOptions } from '@angular-devkit/build-angular';
+import { augmentAppWithServiceWorker } from '@angular-devkit/build-angular/src/utils/service-worker';
+import { normalize, resolve as resolvePath } from '@angular-devkit/core';
+import { NodeJsSyncHost } from '@angular-devkit/core/node';
 import { fork } from 'child_process';
 import * as fs from 'fs';
 import * as ora from 'ora';
@@ -109,6 +112,19 @@ async function _renderUniversal(
   browserOptions: BrowserBuilderOptions,
   numProcesses?: number,
 ): Promise<PrerenderBuilderOutput> {
+  const host = new NodeJsSyncHost();
+  const projectName = context.target && context.target.project;
+  if (!projectName) {
+    throw new Error('The builder requires a target.');
+  }
+
+  const root = normalize(context.workspaceRoot);
+  const projectMetadata = await context.getProjectMetadata(projectName);
+  const projectRoot = resolvePath(
+    root,
+    normalize((projectMetadata.root as string) || ''),
+  );
+
   // Users can specify a different base html file e.g. "src/home.html"
   const indexFile = getIndexOutputFile(browserOptions);
   // We need to render the routes for each locale from the browser output.
@@ -142,6 +158,26 @@ async function _renderUniversal(
     }
 
     spinner.succeed(`Prerendering routes to ${outputPath} complete.`);
+
+    if (browserOptions.serviceWorker) {
+      spinner.start('Generating service worker...');
+      try {
+        await augmentAppWithServiceWorker(
+          host,
+          root,
+          projectRoot,
+          normalize(outputPath),
+          browserOptions.baseHref || '/',
+          browserOptions.ngswConfigPath,
+        );
+      } catch (error) {
+        spinner.fail('Service worker generation failed.');
+
+        return { success: false, error: error.message };
+      }
+
+      spinner.succeed('Service worker generation complete.');
+    }
   }
 
   return browserResult;

modules/builders/testing/hello-world-app/angular.json

@@ -32,6 +32,9 @@
             "scripts": []
           },
           "configurations": {
+            "sw": {
+              "serviceWorker": true
+            },
             "production": {
               "fileReplacements": [
                 {

package.json

@@ -57,6 +57,7 @@
     "@angular/platform-browser-dynamic": "^11.0.0-rc.0",
     "@angular/platform-server": "^11.0.0-rc.0",
     "@angular/router": "^11.0.0-rc.0",
+    "@angular/service-worker": "^11.0.0-rc.0",
     "@bazel/bazelisk": "1.7.3",
     "@bazel/buildifier": "3.5.0",
     "@bazel/hide-bazel-files": "1.7.0",

yarn.lock

@@ -239,6 +239,13 @@
   dependencies:
     tslib "^2.0.0"
 
+"@angular/service-worker@^11.0.0-rc.0":
+  version "11.0.0-rc.2"
+  resolved "https://registry.yarnpkg.com/@angular/service-worker/-/service-worker-11.0.0-rc.2.tgz#a9f34190ce86fe8de2fd53fa4b4549541674c06c"
+  integrity sha512-rWh9EtXfFjl8riov4q+ET94mXJGxGb5KH4LwOfKN/4TKCYyfx03QVyChDH9GxRnolq6sjSeKhI9c0ni3n7dvjA==
+  dependencies:
+    tslib "^2.0.0"
+
 "@babel/code-frame@^7.0.0", "@babel/code-frame@^7.10.4":
   version "7.10.4"
   resolved "https://registry.yarnpkg.com/@babel/code-frame/-/code-frame-7.10.4.tgz#168da1a36e90da68ae8d49c0f1b48c7c6249213a"