feat(build): record angular version in the dom (#13164)

modules/@angular/platform-browser/index.ts

@@ -11,6 +11,10 @@
  * @description
  * Entry point for all public APIs of the platform-browser package.
  */
+import {Version} from '@angular/core';
+/**
+ * @stable
+ */
+export const VERSION = new Version('0.0.0-PLACEHOLDER');
 export * from './src/platform-browser';
-
 // This file only reexports content of the `src` folder. Keep it that way.

modules/@angular/platform-browser/src/browser.ts

@@ -7,7 +7,7 @@
  */
 
 import {CommonModule, PlatformLocation} from '@angular/common';
-import {ApplicationModule, ErrorHandler, NgModule, Optional, PLATFORM_INITIALIZER, PlatformRef, Provider, RootRenderer, Sanitizer, SkipSelf, Testability, createPlatformFactory, platformCore} from '@angular/core';
+import {ApplicationModule, ErrorHandler, NgModule, Optional, PLATFORM_INITIALIZER, PlatformRef, Provider, RootRenderer, Sanitizer, SkipSelf, Testability, VERSION, createPlatformFactory, platformCore} from '@angular/core';
 
 import {AnimationDriver} from '../src/dom/animation_driver';
 import {WebAnimationsDriver} from '../src/dom/web_animations_driver';
@@ -29,6 +29,7 @@ import {DomSanitizer, DomSanitizerImpl} from './security/dom_sanitization_servic
 
 export const INTERNAL_BROWSER_PLATFORM_PROVIDERS: Provider[] = [
   {provide: PLATFORM_INITIALIZER, useValue: initDomAdapter, multi: true},
+  {provide: PLATFORM_INITIALIZER, useValue: recordAngularVersion, multi: true},
   {provide: PlatformLocation, useClass: BrowserPlatformLocation}
 ];
 
@@ -54,6 +55,14 @@ export function initDomAdapter() {
   BrowserGetTestability.init();
 }
 
+export function recordAngularVersion(): void {
+  const domAdapter = getDOM();
+  const body = domAdapter.getElementsByTagName(domAdapter.defaultDoc(), 'body');
+  if (body.length > 0) {
+    domAdapter.setAttribute(body[0], 'ng-version', VERSION.full);
+  }
+}
+
 export function errorHandler(): ErrorHandler {
   return new ErrorHandler();
 }

modules/@angular/platform-browser/src/platform-browser.ts

@@ -16,5 +16,4 @@ export {DOCUMENT} from './dom/dom_tokens';
 export {EVENT_MANAGER_PLUGINS, EventManager} from './dom/events/event_manager';
 export {HAMMER_GESTURE_CONFIG, HammerGestureConfig} from './dom/events/hammer_gestures';
 export {DomSanitizer, SafeHtml, SafeResourceUrl, SafeScript, SafeStyle, SafeUrl} from './security/dom_sanitization_service';
-
-export * from './private_export';
+export * from './private_export';