feat(upgrade): support downgrading multiple modules (#26217)

Currently, calling `downgradeModule()` more than once is not supported.
If one wants to downgrade multiple Angular modules, they can create a
"super-module" that imports all the rest and downgrade that.

This commit adds support for downgrading multiple Angular modules. If
multiple modules are downgraded, then one must explicitly specify the
downgraded module that each downgraded component or injectable belongs
to, when calling `downgradeComponent()` and `downgradeInjectable()`
respectively.

No modification is needed (i.e. there is no need to specify a module for
downgraded components and injectables), if an app is not using
`downgradeModule()` or if there is only one downgraded Angular module.

Fixes #26062

PR Close #26217

packages/examples/upgrade/static/ts/lite-multi/e2e_test/static_lite_multi_spec.ts

@@ -0,0 +1,28 @@
+/**
+ * @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 {browser, by, element} from 'protractor';
+
+import {verifyNoBrowserErrors} from '../../../../../_common/e2e_util';
+
+
+describe('upgrade/static (lite with multiple downgraded modules)', () => {
+  const navButtons = element.all(by.css('nav button'));
+  const mainContent = element(by.css('main'));
+
+  beforeEach(() => browser.get('/upgrade/static/ts/lite-multi/'));
+  afterEach(verifyNoBrowserErrors);
+
+  it('should correctly bootstrap multiple downgraded modules', () => {
+    navButtons.get(1).click();
+    expect(mainContent.getText()).toBe('Component B');
+
+    navButtons.get(0).click();
+    expect(mainContent.getText()).toBe('Component A | ng1(ng2)');
+  });
+});

packages/examples/upgrade/static/ts/lite-multi/module.ts

@@ -0,0 +1,118 @@
+/**
+ * @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
+ */
+
+// #docplaster
+import {Component, Directive, ElementRef, Injectable, Injector, NgModule, StaticProvider, getPlatform} from '@angular/core';
+import {BrowserModule} from '@angular/platform-browser';
+import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
+import {UpgradeComponent, downgradeComponent, downgradeInjectable, downgradeModule} from '@angular/upgrade/static';
+
+
+declare var angular: ng.IAngularStatic;
+
+// An Angular module that declares an Angular service and a component,
+// which in turn uses an upgraded AngularJS component.
+@Component({
+  selector: 'ng2A',
+  template: 'Component A | <ng1A></ng1A>',
+})
+export class Ng2AComponent {
+}
+
+@Directive({
+  selector: 'ng1A',
+})
+export class Ng1AComponentFacade extends UpgradeComponent {
+  constructor(elementRef: ElementRef, injector: Injector) { super('ng1A', elementRef, injector); }
+}
+
+@Injectable()
+export class Ng2AService {
+  getValue() { return 'ng2'; }
+}
+
+@NgModule({
+  imports: [BrowserModule],
+  providers: [Ng2AService],
+  declarations: [Ng1AComponentFacade, Ng2AComponent],
+  entryComponents: [Ng2AComponent],
+})
+export class Ng2AModule {
+  ngDoBootstrap() {}
+}
+
+
+// Another Angular module that declares an Angular component.
+@Component({
+  selector: 'ng2B',
+  template: 'Component B',
+})
+export class Ng2BComponent {
+}
+
+@NgModule({
+  imports: [BrowserModule],
+  declarations: [Ng2BComponent],
+  entryComponents: [Ng2BComponent],
+})
+export class Ng2BModule {
+  ngDoBootstrap() {}
+}
+
+
+// The downgraded Angular modules.
+const downgradedNg2AModule = downgradeModule(
+    (extraProviders: StaticProvider[]) =>
+        (getPlatform() || platformBrowserDynamic(extraProviders)).bootstrapModule(Ng2AModule));
+
+const downgradedNg2BModule = downgradeModule(
+    (extraProviders: StaticProvider[]) =>
+        (getPlatform() || platformBrowserDynamic(extraProviders)).bootstrapModule(Ng2BModule));
+
+
+// The AngularJS app including downgraded modules, components and injectables.
+const appModule =
+    angular.module('exampleAppModule', [downgradedNg2AModule, downgradedNg2BModule])
+        .component('exampleApp', {
+          template: `
+        <nav>
+          <button ng-click="$ctrl.page = page" ng-repeat="page in ['A', 'B']">
+            Page {{ page }}
+          </button>
+        </nav>
+        <hr />
+        <main ng-switch="$ctrl.page">
+          <ng2-a ng-switch-when="A"></ng2-a>
+          <ng2-b ng-switch-when="B"></ng2-b>
+        </main>
+      `,
+          controller: class ExampleAppController{page = 'A';},
+        })
+        .component('ng1A', {
+          template: 'ng1({{ $ctrl.value }})',
+          controller: [
+            'ng2AService', class Ng1AController{
+              value = this.ng2AService.getValue(); constructor(private ng2AService: Ng2AService) {}
+            }
+          ],
+        })
+        .directive('ng2A', downgradeComponent({
+                     component: Ng2AComponent,
+                     downgradedModule: downgradedNg2AModule,
+                     propagateDigest: false,
+                   }))
+        .directive('ng2B', downgradeComponent({
+                     component: Ng2BComponent,
+                     downgradedModule: downgradedNg2BModule,
+                     propagateDigest: false,
+                   }))
+        .factory('ng2AService', downgradeInjectable(Ng2AService, downgradedNg2AModule));
+
+
+// Bootstrap the AngularJS app.
+angular.bootstrap(document.body, [appModule.name]);

packages/examples/upgrade/static/ts/lite/module.ts

@@ -17,7 +17,6 @@ import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
 /* tslint:disable: no-duplicate-imports */
 import {UpgradeComponent} from '@angular/upgrade/static';
 import {downgradeComponent} from '@angular/upgrade/static';
-import {downgradeInjectable} from '@angular/upgrade/static';
 // #docregion basic-how-to
 import {downgradeModule} from '@angular/upgrade/static';
 // #enddocregion