Gain insights into Jest, a versatile testing framework. Learn about fundamental and advanced testing techniques, from unit tests to CI/CD integration, for comprehensive JavaScript application testing.

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Run Tests

Run Tests - No Reset

Jest is a framework for testing applications developed in JavaScript. It has a well-documented and well-maintained range of tools to run tests in parallel. It is simple and works with projects using Babel, TypeScript, Node, React, Angular, Vue, etc. It works well for both client and server testing. 

This course covers Jest in-depth and is agnostic of any specific JavaScript framework. The course begins with the fundamentals of Jest testing, deconstructing the components of a test and covering how to compose basic unit tests and snapshot tests with Jest correctly. Next, it shows the testing of asynchronous code and the code that relies on external dependencies. Lastly, this course illustrates how Jest testing can effectively integrate into the real-world software development cycle through CI/CD pipeline.

It gives you hands-on experience in setting up Jest, types of testing, testing coverage, mocking, and native tooling depth.

…. To come 

… to come 

Mastering Jest: A Complete Guide to Testing

## Installation

First, we need to make sure we have Jest installed. Jest is a regular third-party package that is installable via the [npm](https://www.npmjs.com/package/jest) and [Yarn](https://yarnpkg.com/package/jest) registries.

If we are working inside a Create React App project, Jest is already installed as the test runner. Both were created by and are maintained by Meta. Yarn was also created by this team. CRA also ships with [React Testing Library](https://testing-library.com/).

At the time of writing this, CRA ships with Jest as a production dependency. There are differences in opinion within the React community on this, but because it is inherently not used in production, we suggest moving it to `devDependencies` in `package.json`. Otherwise, install it with one of the following commands:

```
yarn add jest --dev
npm install jest --save-dev
```
Now that it's installed, we need to configure Jest for our needs.

<h2>Running tests</h2>

# Installation

First, we need to make sure we have Jest installed. Jest is a regular third-party package that is installable via the [npm](https://www.npmjs.com/package/jest) and [Yarn](https://yarnpkg.com/package/jest) registries.

If we are working inside a Create React App project, Jest is already installed as the test runner. Both were created by and are maintained by Meta. Yarn was also created by this team. CRA also ships with [React Testing Library](https://testing-library.com/).

At the time of writing this, CRA ships with Jest as a production dependency. There are differences in opinion within the React community on this, but because it is inherently not used in production, we suggest moving it to `devDependencies` in `package.json`. Otherwise, install it with one of the following commands:

```
yarn add jest --dev
npm install jest --save-dev
```
Now that it's installed, we need to configure Jest for our needs.

<h2>Running tests</h2>

Introduction

Setting Up Jest

Jest Matchers

Writing Unit Tests

Writing Snapshot Tests

Asynchronous Code

Mocking

Mocking External Libraries

Working with Jest Mocks

Setup & Teardown

Test Coverage & CI/CD Pipelines

Test Coverage in Jest

Conclusion

Bonus: Best Practices

Bonus: Resources for Continued Learning

Appendix

Installing & Running Jest

Installation

Running tests