Difference Between JEST and Enzyme?
Tags: jest, enzyme, programming, unittesting
Published: 2022-10-17 09:52:10

Hunting for a framework to test the accuracy of the Javascript codebase. _JEST and Enzyme_ serve tremendous accessibilities to test your application code. These resources are one of the best resources/ tools to evaluate the efficiency of client-side components. Many organizations are using this testing framework. 

Testing includes various practices and strategies to evaluate an application's performance, functionality, load, and other aspects. Jest & Enzyme both are good for [streamlining unit testing](https://medium.com/@quokkalabs135/what-is-unit-testing-what-are-its-best-practices-3fab9a337c84). Get into this blog to know where they fall in the same court and where they play individually!

If the application or website has no ideal interface, the user won’t stick to it for long. It could be for navigation, functionality, design, or other reasons. We go through the testing phase to analyze and inspect the overall user interface feel. JEST and Enzyme are here to do this job easier for us. 

## Compare features of Jest v/s Enzyme

### Jest is a framework and Enzyme is a library
Jest is a versatile tool with a suite of testing strategies to bring out most of your expectations. Apart from the basic job of react component testing, you can access more from this. Like you can run numerous test scripts and test the assertion library. 

Moreover, you don't have to use numerous test libraries to examine the whole application setup. One is enough here to manage the complete application.

Beyond this, you can launch a Node-JS-equipped server for your JS-based web application.

When we talk about the Enzyme, it appears as a library solely responsible for testing the react components. It allows integration with other testing libraries to draw the optimum unit testing results.

First, you must configure/ install Node Package manager to start with both.

If you are on the development path to launching a React application, then both tools can test the UI's robust performance.

### Components Examinations in JEST and Enzyme
Jest has a rich collection of integrated tools and features that enables robust React UI Testing. You can easily design well-organized test cases to analyze the functionality & behavior of UIs. It enables the snapshot tool to compare the performance of a UI component. 

On whatever application you are working on, the [JEST](https://jestjs.io/) snapshot will snap the view of expected rendering components and save it. These snapshots are easy-to-understand, readable, regular code written in HTML.

**On each execution of Jest testcases, saved HTML snaps will compare with the rendered output. If they don’t appear the same, it will get pass status. If the snaps don’t match each other, it will get fail status.**

You don’t need to worry about that fail. Just focus a little more and try to match with saved HTML snaps.

Jest snapshot is undoubtedly excellent for comparing or testing application component previews.  While stepping ahead on debugging, you get used to the testing tools and their functionality. Later you understood that it's good to have previous work snaps in your memory to check where you have mistaken or left something or moderate things. It saves you from future mistakes and putting in the extra effort.

Beginners may get annoyed by seeing so many snaps of the codebase, thinking like its’ not so exciting stuff. 

**Enzyme resolves these simple problems of taking frequent snapshots for every test case rendering. It generates the component and then rolls out the APIs list to test various properties and behavior.**


### Rendering in Jest & Enzyme
[Enzyme](https://enzymejs.github.io/enzyme/) offers two types of API for shallow rendering and full rendering. Both are preferred for different test scenarios and functionalities. 

- In shallow rendering, only the parent component will be rendered. All the children's react components will not be part of this. Also, the test cases will be available in a simple format.

Here the simple thing is that we’re not taking so much work and burden. To save time and find the elements more quickly, find () or findWhere().

After that, write assertions for elements.

- This scenario shows a difference from JEST. JEST included parent and child components that are saved in the snapshot. In case of parameter modification, we‘ll consider different versions of the snapshot to know the rendering of components.

- The API for full rendering and shallow rendering is pretty much the same. But you can expect the web page rendering here. You can see everything available on the page.

The enzyme is not overshadowing the shallow rendering with full rendering. It’s only about preferences for rendering or analyzing things. Suppose you have planned integration testing to inspect the behavior and functionality of multiple components. Enzyme Full rendering API is here to manage lots of things.


**Hold on; you can’t go straight to perform the Enzyme full rendering. Here’s a complete set of requirements that need to configure. Full rendering requires the broad library space as a browser most frequently has its JSDOM.**

_Want to know more about javascript testing framework Jest [check this blog from here](https://dev.to/quokkalabs/all-you-need-to-know-about-javascript-testing-jest-3ip7)_


#### In the End
Perform the unit testing in a straightforward open-source testing environment with such outstanding React UI Testing tools. As we know, the react app development market has seen enormous growth in 2022. Developers are developing amazing apps. You should advance with the trend and familiarize yourself with the evolving React App testing tools!

QA and Tester advise accessing Jest to manage the work of the Test runner and Assertion Library. And with Enzyme, you can design the test to examine the UIs.

**When Jest & Enzyme come together, that will reduce the work and speed up the debugging & testing process. Consequently, it will be easier to chunk down the code in a clean format.  All these testcase can be integrated with other advanced automated testing tools and can tweak out the bugs faster.**

These tools boost productivity and confidence in React UI testing and achieve desirable and optimum results. Jest and Enzyme will overcome the complexity and stress of the QA and testers team and be a companion for further testing tasks.