refactor: remove toplevel property accesses (#29329)

PR Close #29329

packages/platform-browser/src/browser/browser_adapter.ts

@@ -63,13 +63,15 @@ const _chromeNumKeyPadMap = {
   '\x90': 'NumLock'
 };
 
-let nodeContains: (a: any, b: any) => boolean;
+const nodeContains: (a: any, b: any) => boolean = (() => {
+  if (global['Node']) {
+    return global['Node'].prototype.contains || function(node: any) {
+      return !!(this.compareDocumentPosition(node) & 16);
+    };
+  }
 
-if (global['Node']) {
-  nodeContains = global['Node'].prototype.contains || function(node) {
-    return !!(this.compareDocumentPosition(node) & 16);
-  };
-}
+  return undefined as any;
+})();
 
 /**
  * A `DomAdapter` powered by full browser DOM APIs.

packages/platform-browser/src/dom/debug/ng_probe.ts

@@ -6,13 +6,14 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import * as core from '@angular/core';
+import {APP_INITIALIZER, ApplicationRef, DebugNode, NgProbeToken, NgZone, Optional, Provider, getDebugNode} from '@angular/core';
+
 import {exportNgVar} from '../util';
 
-const CORE_TOKENS = {
-  'ApplicationRef': core.ApplicationRef,
-  'NgZone': core.NgZone,
-};
+const CORE_TOKENS = (() => ({
+                       'ApplicationRef': ApplicationRef,
+                       'NgZone': NgZone,
+                     }))();
 
 const INSPECT_GLOBAL_NAME = 'probe';
 const CORE_TOKENS_GLOBAL_NAME = 'coreTokens';
@@ -22,17 +23,17 @@ const CORE_TOKENS_GLOBAL_NAME = 'coreTokens';
  * null if the given native element does not have an Angular view associated
  * with it.
  */
-export function inspectNativeElement(element: any): core.DebugNode|null {
-  return core.getDebugNode(element);
+export function inspectNativeElement(element: any): DebugNode|null {
+  return getDebugNode(element);
 }
 
-export function _createNgProbe(coreTokens: core.NgProbeToken[]): any {
+export function _createNgProbe(coreTokens: NgProbeToken[]): any {
   exportNgVar(INSPECT_GLOBAL_NAME, inspectNativeElement);
   exportNgVar(CORE_TOKENS_GLOBAL_NAME, {...CORE_TOKENS, ..._ngProbeTokensToMap(coreTokens || [])});
   return () => inspectNativeElement;
 }
 
-function _ngProbeTokensToMap(tokens: core.NgProbeToken[]): {[name: string]: any} {
+function _ngProbeTokensToMap(tokens: NgProbeToken[]): {[name: string]: any} {
   return tokens.reduce((prev: any, t: any) => (prev[t.name] = t.token, prev), {});
 }
 
@@ -48,12 +49,12 @@ export const ELEMENT_PROBE_PROVIDERS__POST_R3__ = [];
 /**
  * Providers which support debugging Angular applications (e.g. via `ng.probe`).
  */
-export const ELEMENT_PROBE_PROVIDERS__PRE_R3__: core.Provider[] = [
+export const ELEMENT_PROBE_PROVIDERS__PRE_R3__: Provider[] = [
   {
-    provide: core.APP_INITIALIZER,
+    provide: APP_INITIALIZER,
     useFactory: _createNgProbe,
     deps: [
-      [core.NgProbeToken, new core.Optional()],
+      [NgProbeToken, new Optional()],
     ],
     multi: true,
   },

packages/platform-browser/src/dom/dom_renderer.ts

@@ -231,7 +231,7 @@ class DefaultDomRenderer2 implements Renderer2 {
   }
 }
 
-const AT_CHARCODE = '@'.charCodeAt(0);
+const AT_CHARCODE = (() => '@'.charCodeAt(0))();
 function checkNoSyntheticProp(name: string, nameKind: string) {
   if (name.charCodeAt(0) === AT_CHARCODE) {
     throw new Error(

packages/platform-browser/src/dom/events/dom_events.ts

@@ -18,9 +18,8 @@ import {EventManagerPlugin} from './event_manager';
  * addEventListener by 3x.
  */
 const __symbol__ =
-    (typeof Zone !== 'undefined') && (Zone as any)['__symbol__'] || function(v: string): string {
-      return '__zone_symbol__' + v;
-    };
+    (() => (typeof Zone !== 'undefined') && (Zone as any)['__symbol__'] ||
+         function(v: string): string { return '__zone_symbol__' + v; })();
 const ADD_EVENT_LISTENER: 'addEventListener' = __symbol__('addEventListener');
 const REMOVE_EVENT_LISTENER: 'removeEventListener' = __symbol__('removeEventListener');
 
@@ -35,13 +34,18 @@ const NATIVE_REMOVE_LISTENER = 'removeEventListener';
 const stopSymbol = '__zone_symbol__propagationStopped';
 const stopMethodSymbol = '__zone_symbol__stopImmediatePropagation';
 
-const blackListedEvents: string[] =
-    (typeof Zone !== 'undefined') && (Zone as any)[__symbol__('BLACK_LISTED_EVENTS')];
-let blackListedMap: {[eventName: string]: string};
-if (blackListedEvents) {
-  blackListedMap = {};
-  blackListedEvents.forEach(eventName => { blackListedMap[eventName] = eventName; });
-}
+
+const blackListedMap = (() => {
+  const blackListedEvents: string[] =
+      (typeof Zone !== 'undefined') && (Zone as any)[__symbol__('BLACK_LISTED_EVENTS')];
+  if (blackListedEvents) {
+    const res: {[eventName: string]: string} = {};
+    blackListedEvents.forEach(eventName => { res[eventName] = eventName; });
+    return res;
+  }
+  return undefined;
+})();
+
 
 const isBlackListedEvent = function(eventName: string) {
   if (!blackListedMap) {