---
title: "Testing throw with Jest"  
description: "Testing throw with Jest"  
author: "Revati S Misra"  
published: 2023-07-20  
updated: 2023-07-20  
canonical: https://www.mindstick.com/forum/159182/testing-throw-with-jest  
category: "javascript"  
tags: ["testing", "javascript"]  
reading_time: 2 minutes  

---

# Testing throw with Jest

[Testing](https://www.mindstick.com/articles/1849/role-of-testing-in-software-development) throw with [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 test throw with Jest:

1. First, you need to install Jest if you don't have it already. You can do this by running the following command in your terminal:

```plaintext
npm install -g jest
```

1. Once Jest is installed, you need to create a Jest configuration file. This file will tell Jest where to find your unit tests and how to run them. You can create a Jest configuration file by running the following command in your terminal:

```plaintext
jest --init
```

1. This will create a file called `jest.config.js` in your current directory. You can open this file and edit it to specify the location of your unit tests. For example, if your unit tests are located in a folder called `tests`, you would add the following line to your `jest.config.js` file:

```plaintext
"testPathIgnorePatterns": ["node_modules"]
```

1. Once you have created your Jest configuration file, you can start writing your unit tests. To test for a throw, you can use the `expect.toThrow` matcher. For example, the following unit test will test whether the function `myFunction` throws an error:

```plaintext
test("myFunction throws an error", () => {
  expect(myFunction()).toThrow();
});
```

1. Once you have written your unit tests, you can run them by running the following command in your terminal:

```plaintext
jest
```

This will run all of your unit tests and report any failures.

Here are some additional tips for testing throw with Jest:

- You can use the `expect.toThrowError` matcher to test for a specific type of error. For example, the following unit test will test whether the function `myFunction` throws a `TypeError` error:

```plaintext
test("myFunction throws a TypeError", () => {
  expect(myFunction()).toThrowError(TypeError);
});
```

- You can use the `expect.toThrowWith` matcher to test for a specific error message. For example, the following unit test will test whether the function `myFunction` throws an error with the message "This is an error message":

```plaintext
test("myFunction throws an error with the message 'This is an error message'", () => {
  expect(myFunction()).toThrowWith(TypeError, "This is an error message");
});
```


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Original Source: https://www.mindstick.com/forum/159182/testing-throw-with-jest

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