Course Project: Adding logic to the reducer

course-project/src/app/shopping-list/shopping-list.reducer.ts

@@ -0,0 +1,20 @@
+import { Action } from '@ngrx/store';
+
+import { Ingredient } from '../shared/ingredient.model';
+
+const initialState = {
+  ingredients: [
+    new Ingredient('Apples', 5),
+    new Ingredient('Tomatoes', 10),
+  ]
+};
+
+export function shoppingListReducer(state = initialState, action: Action) {
+  switch (action.type) {
+    case 'ADD_INGREDIENT':
+      return {
+        ...state,
+        ingredients: [...state.ingredients, action]
+      };
+  }
+}