freeCodeCamp/curriculum/challenges/chinese/06-quality-assurance/quality-assurance-and-testing-with-chai/test-if-a-value-is-a-string.md

---
id: 587d824d367417b2b2512c52
title: 测试某个值是否为字符串
challengeType: 2
forumTopicId: 301599
dashedName: test-if-a-value-is-a-string
---

# --description--

请注意，本项目在 [这个 Repl.it 项目](https://repl.it/github/freeCodeCamp/boilerplate-mochachai) 的基础上进行开发。你也可以从 [GitHub](https://repl.it/github/freeCodeCamp/boilerplate-mochachai) 上克隆。

`isString` 或 `isNotString` 断言一个值是否为字符串。

# --instructions--

使用 `assert.isString()` 或 `assert.isNotString()` 让所有测试通过。

# --hints--

不应有未通过的测试

```js
(getUserInput) =>
  $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=12').then(
    (data) => {
      assert.equal(data.state, 'passed');
    },
    (xhr) => {
      throw new Error(xhr.responseText);
    }
  );
```

请选择正确的断言—isString 或 isNotString

```js
(getUserInput) =>
  $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=12').then(
    (data) => {
      assert.equal(
        data.assertions[0].method,
        'isNotString',
        'A float number is not a string'
      );
    },
    (xhr) => {
      throw new Error(xhr.responseText);
    }
  );
```

请选择正确的断言—isString 或 isNotString

```js
(getUserInput) =>
  $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=12').then(
    (data) => {
      assert.equal(
        data.assertions[1].method,
        'isString',
        'environment vars are strings (or undefined)'
      );
    },
    (xhr) => {
      throw new Error(xhr.responseText);
    }
  );
```

请选择正确的断言—isString 或 isNotString

```js
(getUserInput) =>
  $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=12').then(
    (data) => {
      assert.equal(data.assertions[2].method, 'isString', 'A JSON is a string');
    },
    (xhr) => {
      throw new Error(xhr.responseText);
    }
  );
```

# --solutions--

```js
/**
  Backend challenges don't need solutions, 
  because they would need to be tested against a full working project. 
  Please check our contributing guidelines to learn more.
*/
```