adding demo for step 2-6

step2-06/exercise/src/reducers/index.ts

@@ -0,0 +1,27 @@
+import { Store } from '../store';
+import { addTodo, remove, complete, clear } from './pureFunctions';
+
+function todoReducer(state: Store['todos'] = {}, action: any): Store['todos'] {
+  switch (action.type) {
+    case 'addTodo':
+      return addTodo(state, action.id, action.label);
+
+    case 'remove':
+      return remove(state, action.id);
+
+    case 'clear':
+      return clear(state);
+
+    case 'complete':
+      return complete(state, action.id);
+  }
+
+  return state;
+}
+
+export function reducer(state: Store, action: any): Store {
+  return {
+    todos: todoReducer(state.todos, action),
+    filter: 'all'
+  };
+}