update

src/app.js

@@ -0,0 +1,48 @@
+import {createStore} from 'redux';
+
+// Step 3 define reducers
+const reducer = function(state={books:[]}, action){
+    switch(action.type){
+        case "POST_BOOK":
+            // let books = state.books.concat(action.payload);
+            // return {books};
+            return {books: [...state.books, ...action.payload]};
+        break;
+    }
+    return state;
+};
+
+// Step 1 create the store
+const store = createStore(reducer);
+
+store.subscribe(function(){
+    console.log('current state is : ', store.getState());
+});
+
+// Step 2 create and dispatch actions
+store.dispatch({
+    type: "POST_BOOK", 
+    payload: [{
+        id: 1,
+        title: 'book title',
+        description: 'book description',
+        price: 33.33,
+    },
+    {
+        id: 2,
+        title: 'book title 2',
+        description: 'book description 2',
+        price: 45.32,
+    }]
+});
+
+// Dispatch a second action
+store.dispatch({
+    type: "POST_BOOK", 
+    payload: [{
+        id: 1,
+        title: 'book title 3',
+        description: 'book description 3',
+        price: 33.33,
+    }]
+});