freeCodeCamp/guide/english/certifications/information-security-and-quality-assurance/quality-assurance-and-testing-with-chai/test-if-a-value-is-a-string/index.md

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title: Test if a Value is a String
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# Test if a Value is a String

To begin, locate the file "tests/1_unit_tests.js" and scroll to the suite of tests for 'Strings'.

This file contains multiple suites of tests for the project, and this challenge requires you to make the tests in ``` /** 13 */``` pass.


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## Hints

### Hint 1

Check the responses of the error messages if your tests fail, and make sure you understand the types of the parameters being checked by the assertion.

### Hint 2

The lines in the test should be changed from `assert.fail()` to either `assert.isString()` or `assert.isNotString()`.


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## Solutions

<details><summary>Solution 1 (Click to Show/Hide)</summary>

```js
/** 13 - #isString asserts that the actual value is a string. **/
test('#isString, #isNotString', function() {
  assert.isNotString(Math.sin(Math.PI / 4), 'a float is not a string');
  assert.isString(process.env.PATH, 'env vars are strings (or undefined)');
  assert.isString(JSON.stringify({ type: 'object' }), 'a JSON is a string');
});
```
</details>