test(upgrade): run tests against multiple AngularJS versions (#22167)

Fixes #19332

PR Close #22167

packages/upgrade/test/common/downgrade_component_adapter_spec.ts

@@ -10,9 +10,9 @@ import {TestBed, getTestBed, inject} from '@angular/core/testing';
 import * as angular from '@angular/upgrade/src/common/angular1';
 import {DowngradeComponentAdapter, groupNodesBySelector} from '@angular/upgrade/src/common/downgrade_component_adapter';
 
-import {nodes} from './test_helpers';
+import {nodes, withEachNg1Version} from './test_helpers';
 
-{
+withEachNg1Version(() => {
   describe('DowngradeComponentAdapter', () => {
     describe('groupNodesBySelector', () => {
       it('should return an array of node collections for each selector', () => {
@@ -190,4 +190,4 @@ import {nodes} from './test_helpers';
     });
 
   });
-}
+});

packages/upgrade/test/common/test_helpers.ts

@@ -5,6 +5,57 @@
  * 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 {setAngularJSGlobal} from '@angular/upgrade/src/common/angular1';
+
+
+const ng1Versions = [
+  {
+    label: '1.5',
+    files: ['angular-1.5/angular.js', 'angular-mocks-1.5/angular-mocks.js'],
+  },
+  {
+    label: '1.6',
+    files: ['angular/angular.js', 'angular-mocks/angular-mocks.js'],
+  },
+];
+
+export function createWithEachNg1VersionFn(setNg1: typeof setAngularJSGlobal) {
+  return (specSuite: () => void) => ng1Versions.forEach(({label, files}) => {
+    describe(`[AngularJS v${label}]`, () => {
+      beforeAll(done => {
+        // Load AngularJS before running tests.
+        files
+            .reduce(
+                (prev, file) => prev.then(() => new Promise<void>((resolve, reject) => {
+                                            const script = document.createElement('script');
+                                            script.src = `base/node_modules/${file}`;
+                                            script.onerror = reject;
+                                            script.onload = () => {
+                                              document.body.removeChild(script);
+                                              resolve();
+                                            };
+                                            document.body.appendChild(script);
+                                          })),
+                Promise.resolve())
+            .then(() => setNg1((window as any).angular))
+            .then(done, done.fail);
+      });
+
+      afterAll(() => {
+        // In these tests we are loading different versions of AngularJS on the same window.
+        // AngularJS leaves an "expandoId" property on `document`, which can trick subsequent
+        // `window.angular` instances into believing an app is already bootstrapped.
+        (window as any).angular.element(document).removeData();
+
+        // Remove AngularJS to leave a clean state for subsequent tests.
+        setNg1(undefined);
+        delete (window as any).angular;
+      });
+
+      specSuite();
+    });
+  });
+}
 
 export function html(html: string): Element {
   // Don't return `body` itself, because using it as a `$rootElement` for ng1
@@ -33,3 +84,5 @@ export function nodes(html: string) {
   div.innerHTML = html.trim();
   return Array.prototype.slice.call(div.childNodes);
 }
+
+export const withEachNg1Version = createWithEachNg1VersionFn(setAngularJSGlobal);