Add very basic reselect usage

containers/App.js

@@ -5,6 +5,7 @@ import AddTodo from '../components/AddTodo'
 import TodoList from '../components/TodoList'
 import Footer from '../components/Footer'
 import { memoize, createMemoizedFunction } from '../memoize'
+import { createStructuredSelector } from 'reselect';
 
 function selectTodos(todos, filter) {
   console.log("Recalculating selectTodos");
@@ -75,15 +76,15 @@ App.propTypes = {
   ]).isRequired
 }
 
-// Which props do we want to inject, given the global state?
-// Note: use https://github.com/faassen/reselect for better performance.
-function select(state) {
-  return {
-    todos: state.todos,
-    visibilityFilter: state.visibilityFilter,
-    currentTheme: state.currentTheme
-  }
-}
+const todosSelector = state => state.todos;
+const visibilityFilterSelector = state => state.visibilityFilter;
+const currentThemeSelector = state => state.currentTheme;
+
+const select = createStructuredSelector({
+  todos: todosSelector,
+  visibilityFilter: visibilityFilterSelector,
+  currentTheme: currentThemeSelector
+});
 
 // Wrap the component to inject dispatch and state into it
 export default connect(select)(App)

package.json

@@ -21,7 +21,8 @@
     "react": "^0.14.0",
     "react-dom": "^0.14.0",
     "react-redux": "^4.0.0",
-    "redux": "^3.0.0"
+    "redux": "^3.0.0",
+    "reselect": "^2.0.0"
   },
   "devDependencies": {
     "babel-core": "^5.6.18",