fix(@schematics/angular): ensure Angular builders are migrated to latest versions

The package group format required to automatically update the builder packages was not supported until CLI 7.2.  For older CLI versions performing the update, this new migration will update the builders instead.  Once the CLI is updated to at least 7.2, the update algorithm itself will handle the update.

Author: clydin

packages/schematics/angular/migrations/update-8/index.ts

@@ -13,6 +13,7 @@ import {
 import { updatePackageJson, updateTsLintConfig } from './codelyzer-5';
 import { updateES5Projects } from './differential-loading';
 import { dropES2015Polyfills } from './drop-es6-polyfills';
+import { updateBuilders } from './update-builders';
 
 export { updateLazyModulePaths } from './update-lazy-module-paths';
 
@@ -23,6 +24,7 @@ export default function(): Rule {
       updatePackageJson(),
       dropES2015Polyfills(),
       updateES5Projects(),
+      updateBuilders(),
     ]);
   };
 }

packages/schematics/angular/migrations/update-8/update-builders.ts

@@ -0,0 +1,49 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * 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 { SchematicContext, Tree } from '@angular-devkit/schematics';
+import { NodePackageInstallTask } from '@angular-devkit/schematics/tasks';
+import { addPackageJsonDependency, getPackageJsonDependency } from '../../utility/dependencies';
+import { latestVersions } from '../../utility/latest-versions';
+
+export function updateBuilders() {
+  return (host: Tree, context: SchematicContext) => {
+    let updates = false;
+
+    let current = getPackageJsonDependency(host, '@angular-devkit/build-angular');
+    if (current && current.version !== latestVersions.DevkitBuildAngular) {
+      updates = true;
+      addPackageJsonDependency(
+        host,
+        {
+          type: current.type,
+          name: '@angular-devkit/build-angular',
+          version: latestVersions.DevkitBuildAngular,
+          overwrite: true,
+        },
+      );
+    }
+
+    current = getPackageJsonDependency(host, '@angular-devkit/build-ng-packagr');
+    if (current && current.version !== latestVersions.DevkitBuildNgPackagr) {
+      updates = true;
+      addPackageJsonDependency(
+        host,
+        {
+          type: current.type,
+          name: '@angular-devkit/build-ng-packagr',
+          version: latestVersions.DevkitBuildNgPackagr,
+          overwrite: true,
+        },
+      );
+    }
+
+    if (updates) {
+      context.addTask(new NodePackageInstallTask());
+    }
+  };
+}