83 lines
3.0 KiB
Markdown
83 lines
3.0 KiB
Markdown
|
---
|
||
|
|
id: 5a24c314108439a4d4036158
|
||
|
|
title: Never Mutate State
|
||
|
|
challengeType: 6
|
||
|
|
isRequired: false
|
||
|
|
videoUrl: ''
|
||
|
|
localeTitle: ''
|
||
|
|
---
|
||
|
|
|
||
|
|
## Description
|
||
|
|
undefined
|
||
|
|
|
||
|
|
## Instructions
|
||
|
|
<section id="instructions"> يوجد <code>store</code> <code>reducer</code> في محرر الشفرات لإدارة عناصر المهام. قم <code>ADD_TO_DO</code> كتابة حالة <code>ADD_TO_DO</code> في المخفض لإلحاق الحالة الجديدة بالحالة. هناك عدة طرق لتحقيق ذلك باستخدام JavaScript قياسي أو ES6. تحقق مما إذا كان يمكنك العثور على طريقة لإرجاع مجموعة جديدة مع العنصر من <code>action.todo</code> إلى النهاية. </section>
|
||
|
|
|
||
|
|
## Tests
|
||
|
|
<section id='tests'>
|
||
|
|
|
||
|
|
```yml
|
||
|
|
tests:
|
||
|
|
- text: يجب أن يكون مخزن Redux موجودًا وتهيئة بحالة مساوية لصفيف <code>todos</code> في محرر التعليمة البرمجية.
|
||
|
|
testString: 'assert((function() { const todos = [ "Go to the store", "Clean the house", "Cook dinner", "Learn to code" ]; const initialState = store.getState(); return Array.isArray(initialState) && initialState.join(",") === todos.join(","); })(), "The Redux store should exist and initialize with a state equal to the <code>todos</code> array in the code editor.");'
|
||
|
|
- text: <code>addToDo</code> و <code>immutableReducer</code> يجب أن يكونا كلاهما.
|
||
|
|
testString: 'assert(typeof addToDo === "function" && typeof immutableReducer === "function", "<code>addToDo</code> and <code>immutableReducer</code> both should be functions.");'
|
||
|
|
- text: يجب أن يؤدي إرسال إجراء من النوع <code>ADD_TO_DO</code> على مخزن Redux إلى إضافة عنصر <code>todo</code> ويجب عدم تحوّل الحالة.
|
||
|
|
testString: 'assert((function() { const initialState = store.getState(); const isFrozen = DeepFreeze(initialState); store.dispatch(addToDo("__TEST__TO__DO__")); const finalState = store.getState(); const expectedState = [ "Go to the store", "Clean the house", "Cook dinner", "Learn to code", "__TEST__TO__DO__" ]; return( isFrozen && DeepEqual(finalState, expectedState)); })(), "Dispatching an action of type <code>ADD_TO_DO</code> on the Redux store should add a <code>todo</code> item and should NOT mutate state.");'
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Challenge Seed
|
||
|
|
<section id='challengeSeed'>
|
||
|
|
|
||
|
|
<div id='jsx-seed'>
|
||
|
|
|
||
|
|
```jsx
|
||
|
|
const ADD_TO_DO = 'ADD_TO_DO';
|
||
|
|
|
||
|
|
// A list of strings representing tasks to do:
|
||
|
|
const todos = [
|
||
|
|
'Go to the store',
|
||
|
|
'Clean the house',
|
||
|
|
'Cook dinner',
|
||
|
|
'Learn to code',
|
||
|
|
];
|
||
|
|
|
||
|
|
const immutableReducer = (state = todos, action) => {
|
||
|
|
switch(action.type) {
|
||
|
|
case ADD_TO_DO:
|
||
|
|
// don't mutate state here or the tests will fail
|
||
|
|
return
|
||
|
|
default:
|
||
|
|
return state;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
// an example todo argument would be 'Learn React',
|
||
|
|
const addToDo = (todo) => {
|
||
|
|
return {
|
||
|
|
type: ADD_TO_DO,
|
||
|
|
todo
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
const store = Redux.createStore(immutableReducer);
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</section>
|
||
|
|
|
||
|
|
## Solution
|
||
|
|
<section id='solution'>
|
||
|
|
|
||
|
|
```js
|
||
|
|
// solution required
|
||
|
|
```
|
||
|
|
</section>
|