---
title: "unit test in Nodejs using Jest"  
description: "unit test in Nodejs using Jest"  
author: "Revati S Misra"  
published: 2023-07-20  
updated: 2023-07-20  
canonical: https://www.mindstick.com/forum/159176/unit-test-in-nodejs-using-jest  
category: "javascript"  
tags: ["testing", "javascript", "unit testing"]  
reading_time: 3 minutes  

---

# unit test in Nodejs using Jest

[unit test](https://www.mindstick.com/forum/157908/what-is-a-unit-test-how-can-unit-tests-use-to-ensure-the-correctness-and-robustness-of-software) in [Nodejs](https://www.mindstick.com/blog/637/create-and-run-a-html-page-in-nodejs-in-windows-os) using [Jest](https://www.mindstick.com/forum/159175/difference-between-it-and-test-in-jest)

## Replies

### Reply by Aryan Kumar

Sure, here are the steps on how to write a [unit](https://www.mindstick.com/articles/44359/store-your-valuable-items-in-a-mini-storage-unit) [test](https://yourviews.mindstick.com/story/1427/explosive-facts-about-trinity-test-world-s-first-nuclear-bomb) in Node.js using Jest:

1. Install Jest as a dependency in your project. You can do this by running the following command in your terminal:

```plaintext
npm install jest --save-dev
```

Create a test file. Test files in Jest are typically named with the `.test.js` extension. For example, if you are testing a function called `myFunction()`, you would create a file called `myFunction.test.js`.

Write your test. Jest tests are written in BDD style, which means that they are structured like sentences. The first part of the sentence is the `describe()` block, which gives an overview of the test. The second part of the sentence is the `test()` block, which contains the actual test.

For example, the following code shows how to write a test for the `myFunction()` function:

```plaintext
describe("myFunction", () => {
  test("should return the sum of two numbers", () => {
    const result = myFunction(10, 20);
    expect(result).toBe(30);
  });
});
```

In this code, the `describe()` block gives an overview of the test. It says that this test is for the `myFunction()` function and that it should check that the function returns the sum of two numbers. The `test()` block contains the actual test. It calls the `myFunction()` function with the arguments 10 and 20 and asserts that the result is 30.

1. Run your tests. You can run your tests by running the following command in your terminal:

```plaintext
jest
```

This will run all of the tests in your project and report any errors or failures.

Here are some additional things to keep in mind when writing unit tests in Node.js using Jest:

- Jest provides a number of assertions that you can use to test your code. You can find a list of all of the assertions at the Jest documentation: https://jestjs.io/.
- Jest also provides a number of matchers that you can use to compare values. You can find a list of all of the matchers at the Jest documentation: https://jestjs.io/docs/using-matchers.
- Jest supports asynchronous tests. You can write asynchronous tests by using the `async` and `await` keywords.
- Jest also supports snapshot testing. Snapshot testing allows you to compare the output of your code to a snapshot of the output that you have saved. This can be helpful for detecting changes in your code that have not been properly tested.


---

Original Source: https://www.mindstick.com/forum/159176/unit-test-in-nodejs-using-jest

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