fix: keep search state ephemeral

Author: HuntingBook

lib/todo-app.js

@@ -5,10 +5,25 @@ if (typeof require !== 'undefined' && this.window !== this) {
     route, section, span, strong, text, ul } = require('./elmish.js');
 }
 
-var initial_model = {
+function set_search_state(model, value) {
+  Object.defineProperty(model, 'search', {
+    value: value || '',
+    writable: true,
+    configurable: true,
+    enumerable: false
+  });
+  return model;
+}
+
+function clone_model(model) {
+  var cloned = JSON.parse(JSON.stringify(model));
+  return set_search_state(cloned, model && model.search);
+}
+
+var initial_model = set_search_state({
   todos: [],
   hash: "#/"
-}
+}, "")
 
 /**
  * `update` transforms the `model` based on the `action`.
@@ -18,7 +33,7 @@ var initial_model = {
  * @return {Object} new_model - the transformed model.
  */
 function update(action, model, data) {
-  var new_model = JSON.parse(JSON.stringify(model)) // "clone" the model
+  var new_model = clone_model(model) // "clone" the model
 
   switch(action) {
     case 'ADD':
@@ -104,7 +119,7 @@ function update(action, model, data) {
         window.location.hash // : '#/';
       break;
     case 'SEARCH':
-      new_model.search = data;
+      set_search_state(new_model, data);
       break;
     default: // if action unrecognised or undefined,
       return model; // return model unmodified