fix(Store): Use injector to get reducers provided via InjectionTokens (#259)

The injector behavior is different when compiled through AOT such that
provided tokens aren't resolved before the factory function is executed.
This fix uses the injector to get the reducers provided through tokens.

Reference #189

Author: brandonroberts

modules/store/src/store_module.ts

@@ -4,7 +4,7 @@ import {
   ModuleWithProviders,
   OnDestroy,
   InjectionToken,
-  Optional,
+  Injector,
 } from '@angular/core';
 import {
   Action,
@@ -114,10 +114,7 @@ export class StoreModule {
         },
         {
           provide: INITIAL_REDUCERS,
-          deps: [
-            _INITIAL_REDUCERS,
-            [new Optional(), new Inject(_STORE_REDUCERS)],
-          ],
+          deps: [Injector, _INITIAL_REDUCERS, [new Inject(_STORE_REDUCERS)]],
           useFactory: _createStoreReducers,
         },
         {
@@ -185,8 +182,9 @@ export class StoreModule {
           provide: FEATURE_REDUCERS,
           multi: true,
           deps: [
+            Injector,
             _FEATURE_REDUCERS,
-            [new Optional(), new Inject(_FEATURE_REDUCERS_TOKEN)],
+            [new Inject(_FEATURE_REDUCERS_TOKEN)],
           ],
           useFactory: _createFeatureReducers,
         },
@@ -196,20 +194,20 @@ export class StoreModule {
 }
 
 export function _createStoreReducers(
+  injector: Injector,
   reducers: ActionReducerMap<any, any>,
   tokenReducers: ActionReducerMap<any, any>
 ) {
-  return reducers instanceof InjectionToken ? tokenReducers : reducers;
+  return reducers instanceof InjectionToken ? injector.get(reducers) : reducers;
 }
 
 export function _createFeatureReducers(
+  injector: Injector,
   reducerCollection: ActionReducerMap<any, any>[],
   tokenReducerCollection: ActionReducerMap<any, any>[]
 ) {
   return reducerCollection.map((reducer, index) => {
-    return reducer instanceof InjectionToken
-      ? tokenReducerCollection[index]
-      : reducer;
+    return reducer instanceof InjectionToken ? injector.get(reducer) : reducer;
   });
 }