fix(core): should check Zone existance when scheduleMicroTask (#20656)

PR Close #20656

packages/core/src/util.ts

@@ -21,6 +21,8 @@ const __self = typeof self !== 'undefined' && typeof WorkerGlobalScope !== 'unde
     self instanceof WorkerGlobalScope && self;
 const __global = typeof global !== 'undefined' && global;
 const _global: {[name: string]: any} = __window || __global || __self;
+
+const promise: Promise<any> = Promise.resolve(0);
 /**
  * Attention: whenever providing a new value, be sure to add an
  * entry into the corresponding `....externs.js` file,
@@ -52,7 +54,12 @@ export function getSymbolIterator(): string|symbol {
 }
 
 export function scheduleMicroTask(fn: Function) {
+  if (typeof Zone === 'undefined') {
+    // use promise to schedule microTask instead of use Zone
+    promise.then(() => { fn && fn.apply(null, null); });
+  } else {
     Zone.current.scheduleMicroTask('scheduleMicrotask', fn);
+  }
 }
 
 // JS has NaN !== NaN

packages/platform-browser/animations/src/animation_renderer.ts

@@ -19,6 +19,7 @@ export class AnimationRendererFactory implements RendererFactory2 {
   private _animationCallbacksBuffer: [(e: any) => any, any][] = [];
   private _rendererCache = new Map<Renderer2, BaseAnimationRenderer>();
   private _cdRecurDepth = 0;
+  private promise: Promise<any> = Promise.resolve(0);
 
   constructor(
       private delegate: RendererFactory2, private engine: AnimationEngine, private _zone: NgZone) {
@@ -69,7 +70,8 @@ export class AnimationRendererFactory implements RendererFactory2 {
   }
 
   private _scheduleCountTask() {
-    Zone.current.scheduleMicroTask('incremenet the animation microtask', () => this._microtaskId++);
+    // always use promise to schedule microtask instead of use Zone
+    this.promise.then(() => { this._microtaskId++; });
   }
 
   /* @internal */