---
id: 587d824a367417b2b2512c46
title: Learn How JavaScript Assertions Work
challengeType: 2
videoUrl: ''
localeTitle: 了解JavaScript断言的工作原理
---
## Description
提醒一下,这个项目是基于Glitch的以下入门项目构建的,或者是从GitHub克隆的。使用assert.isNull()或assert.isNotNull()来使测试通过。
## Instructions
## Tests
```yml
tests:
- text: 所有测试都应该通过
testString: getUserInput => $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=0').then(data => {assert.equal(data.state,'passed'); }, xhr => { throw new Error(xhr.responseText); })
- text: 选择正确的断言 - isNull vs. isNotNull
testString: getUserInput => $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=0').then(data => { assert.equal(data.assertions[0].method, 'isNull', 'Null is null'); }, xhr => { throw new Error(xhr.responseText); })
- text: 选择正确的断言 - isNull vs. isNotNull
testString: getUserInput => $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=0').then(data => { assert.equal(data.assertions[1].method, 'isNotNull', '1 is not null'); }, xhr => { throw new Error(xhr.responseText); })
```
## Challenge Seed
## Solution
```js
// solution required
```