freeCodeCamp/curriculum/challenges/english/06-quality-assurance/quality-assurance-and-testing-with-chai/test-if-a-value-falls-within-a-specific-range.md

---
id: 587d824c367417b2b2512c4f
title: Test if a Value Falls within a Specific Range
challengeType: 2
forumTopicId: 301598
---

## Description

<section id='description'>

As a reminder, this project is being built upon the following starter project on <a href="https://repl.it/github/freeCodeCamp/boilerplate-mochachai">Repl.it</a>, or cloned from <a href='https://github.com/freeCodeCamp/boilerplate-mochachai/'>GitHub</a>.

```javascript
.approximately(actual, expected, delta, [message])
```

Asserts that the `actual` is equal to `expected`, to within a +/- `delta` range.

</section>

## Instructions

<section id='instructions'>

Within `tests/1_unit-tests.js` under the test labelled `#10` in the `Comparisons` suite, change each `assert` to `assert.approximately` to make the test pass (should evaluate to `true`).

Choose the minimum range (3rd parameter) to make the test always pass. It should be less than 1.

</section>

## Tests

<section id='tests'>

```yml
tests:
  - text: All tests should pass.
    testString: getUserInput => $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=9').then(data => {assert.equal(data.state,'passed'); }, xhr => { throw new Error(xhr.responseText); })
  - text: You should choose the correct range for the first assertion - `approximately(actual, expected, range)`.
    testString: getUserInput => $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=9').then(data => {  assert.equal(data.assertions[0].method, 'approximately');  assert.equal(data.assertions[0].args[2], 0.5, 'weirdNumbers(0.5) is in the range (0.5, 1.5]. It\'s within 1 +/- 0.5'); }, xhr => { throw new Error(xhr.responseText); })
  - text: You should choose the correct range for the second assertion - `approximately(actual, expected, range)`.
    testString: getUserInput => $.get(getUserInput('url') + '/_api/get-tests?type=unit&n=9').then(data => {  assert.equal(data.assertions[1].method, 'approximately');  assert.equal(data.assertions[1].args[2], 0.8, 'weirdNumbers(0.2) is in the range (0.2, 1.2]. It\'s within 1 +/- 0.8'); }, xhr => { throw new Error(xhr.responseText); })
```

</section>

## Challenge Seed

<section id='challengeSeed'>

</section>

## Solution

<section id='solution'>

```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.
*/
```

</section>