19-logout-metareducer

src/app/shared/state/index.ts

@@ -1,6 +1,7 @@
 import { ActionReducerMap, createSelector, MetaReducer } from "@ngrx/store";
 import * as fromAuth from "./auth.reducer";
 import * as fromBooks from "./books.reducer";
+import { logoutMetareducer } from "./logout.metareducer";
 
 export interface State {
   auth: fromAuth.State;
@@ -12,7 +13,7 @@ export const reducers: ActionReducerMap<State> = {
   books: fromBooks.reducer
 };
 
-export const metaReducers: MetaReducer<State>[] = [];
+export const metaReducers: MetaReducer<State>[] = [logoutMetareducer];
 
 /**
  * Auth Selectors

src/app/shared/state/logout.metareducer.ts

@@ -1,2 +1,12 @@
 import { ActionReducer, Action } from "@ngrx/store";
 import { AuthUserActions } from "src/app/auth/actions";
+
+export function logoutMetareducer(reducer: ActionReducer<any>) {
+  return function(state: any, action: Action) {
+    if (action.type === AuthUserActions.logout.type) {
+      return reducer(undefined, action);
+    }
+
+    return reducer(state, action);
+  };
+}