fix(Effects): Simplify decorator handling for Closure compatibility

Author: robwormald

modules/effects/spec/effects_metadata.spec.ts

@@ -23,26 +23,6 @@ describe('Effect Metadata', () => {
       ]);
     });
 
-    it('should get the effects metadata for a downleveled class instance', () => {
-      class Fixture {
-        static get propDecorators() {
-          return {
-            a: [{ type: Effect, args: [{ dispatch: false }] }],
-            b: [{ type: Effect, args: [] }],
-            c: [{ type: Effect }],
-          };
-        }
-      }
-
-      const mock = new Fixture();
-
-      expect(getSourceMetadata(mock)).toEqual([
-        { propertyName: 'a', dispatch: false },
-        { propertyName: 'b', dispatch: true },
-        { propertyName: 'c', dispatch: true },
-      ]);
-    });
-
     it('should return an empty array if the class has not been decorated', () => {
       class Fixture {
         a: any;

modules/effects/src/effects_metadata.ts

@@ -3,63 +3,32 @@ import { ignoreElements } from 'rxjs/operator/ignoreElements';
 import { Observable } from 'rxjs/Observable';
 import { compose } from '@ngrx/store';
 
-const METADATA_KEY = '@ngrx/effects';
+const METADATA_KEY = '__@ngrx/effects__';
 const r: any = Reflect;
 
 export interface EffectMetadata {
   propertyName: string;
   dispatch: boolean;
 }
 
-function hasStaticMetadata(sourceType: any): boolean {
-  return !!(sourceType as any).propDecorators;
-}
-
-function getStaticMetadata(sourceType: any): EffectMetadata[] {
-  const propDecorators = sourceType.propDecorators;
-  return Object.keys(propDecorators).reduce(
-    (all, key) => all.concat(getStaticMetadataEntry(propDecorators[key], key)),
-    []
-  );
-}
-
-function getStaticMetadataEntry(metadataEntry: any, propertyName: string) {
-  return metadataEntry
-    .filter((entry: any) => entry.type === Effect)
-    .map((entry: any) => {
-      let dispatch = true;
-      if (entry.args && entry.args.length) {
-        dispatch = !!entry.args[0].dispatch;
-      }
-      return { propertyName, dispatch };
-    });
-}
-
 function getEffectMetadataEntries(sourceProto: any): EffectMetadata[] {
-  if (hasStaticMetadata(sourceProto.constructor)) {
-    return getStaticMetadata(sourceProto.constructor);
-  }
-
-  if (r.hasOwnMetadata(METADATA_KEY, sourceProto)) {
-    return r.getOwnMetadata(METADATA_KEY, sourceProto);
-  }
-
-  return [];
+  return sourceProto.constructor[METADATA_KEY] || [];
 }
 
 function setEffectMetadataEntries(sourceProto: any, entries: EffectMetadata[]) {
-  r.defineMetadata(METADATA_KEY, entries, sourceProto);
+  const constructor = sourceProto.constructor;
+  const meta: EffectMetadata[] = constructor.hasOwnProperty(METADATA_KEY)
+    ? (constructor as any)[METADATA_KEY]
+    : Object.defineProperty(constructor, METADATA_KEY, { value: [] })[
+        METADATA_KEY
+      ];
+  Array.prototype.push.apply(meta, entries);
 }
 
-/**
- * @Annotation
- */
 export function Effect({ dispatch } = { dispatch: true }): PropertyDecorator {
   return function(target: any, propertyName: string) {
-    const effects: EffectMetadata[] = getEffectMetadataEntries(target);
     const metadata: EffectMetadata = { propertyName, dispatch };
-
-    setEffectMetadataEntries(target, [...effects, metadata]);
+    setEffectMetadataEntries(target, [metadata]);
   };
 }