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Best JavaScript Frameworks — FrontEnd, BackEnd and Testing Frameworks

Sanjam Singh
Feb 23 · 12 min read
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credit: getflywheel

JavaScript is a programming language commonly used in web development. It was originally developed by Netscape as a means to add dynamic and interactive elements to websites. JavaScript is a client-side scripting language, which means the source code is processed by the client’s web browser rather than on the web server. JavaScript is the most commonly used language for the 8th year straight with 67.7% people opting for it.This means JavaScript functions can run after a webpage has loaded without communicating with the server. For example, a JavaScript function may check a web form before it is submitted to make sure all the required fields have been filled out. The JavaScript code can produce an error message before any information is actually transmitted to the server.

Few JavaScript frameworks based on the following some facts:

  • It keeps growing and is maintained up to date and probably will be maintained as predictable future.
  • It Considered popular based on some reliable sites such as GitHub, trends, Google Trends, etc.
  • It has a large active community.

Front End JavaScript Frameworks

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credit: Hanna Söderström

JavaScript frameworks are JS programming libraries that have pre-written code ready-to-use functions and patterns to use for standard programming functions and tasks. It’s a framework to create websites or web applications around. They are free and open-source. It will increase your productivity. Some components of the website do not need to be custom-made, so you can build and expand on pre-built ones. Frameworks are more adaptable for website design and most website developers. Let’s take a look at the best JS Frameworks:

1. React.js

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credit: Dhruv Patel

React is an open-source, front end, JavaScript library for building user interfaces or UI components. It is maintained by Facebook and a community of individual developers and companies. React can be used as a base in the development of single-page or mobile applications. However, React is only concerned with state management and rendering that state to the DOM, so creating React applications usually requires the use of additional libraries for routing, and fully-fledged form solutions. React Router and Formik are examples of such libraries respectively. A lot of business giants are currently using it: AirBNB, PayPal, Netflix, etc.

<div id="myReactApp"></div>

<script type="text/babel">
function Greeter(props) {
return <h1>{props.greeting}</h1>
}
var App = <Greeter greeting="Hello World!" />;
ReactDOM.render(App, document.getElementById('myReactApp'));
</script>
  • React introduced the component-based rendering mechanism where one doesn’t need to reload components on a page if there has been no change to its data. React provides the ability to re-render only components that received new data.
  • New features are being developed for React as we speak, including React Fiber for better concurrency, React hooks to manage functional components with less boilerplate code, React suspense for better rendering, etc. Therefore, React is evolving pretty fast.
  • 71.7% of JavaScript devs are currently using React whereas an additional 12% have shown a keen interest to learn it in future as per State Of JS 2019 survey. This marks an impressive jump of almost 8% from previous year where the active user figure stood at 64%.
  • In Stack Overflow’s developer survey 2020, React was ranked the 2nd most popular web framework with 35.9% votes behind jQuery which has been steadily losing share to react.

2. Vue.js

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credit: Sergey Migalnikov

Vue.js is an open-source model–view–viewmodel front end JavaScript framework for building user interfaces and single-page applications. It was created by Evan You, and is maintained by him and the rest of the active core team members. A developer working for Google who took inspiration from Angular to deliver a simple lightweight and efficient alternative in the form of Vue.js. Although Vue has adopted most of its features from React and Angular, it has made major improvements on those features to deliver a better, easy to use, and secure framework. The biggest example of this approach is that Vue offers a 2-way data binding as seen in Angular and ‘Virtual DOM’ as seen in React.

<template>
<div id="VueApp">
<button-clicked v-bind:initial-count="0"></button-clicked>
</div>
</template>
<script>
Vue.component('button-clicked', {
props: ['initialCount'],
data: () => ({
count: 0,
}),
template: '<button v-on:click="onClick">Clicked {{ count }} times</button>',
computed: {
countTimesTwo() {
return this.count * 2;
}
},
watch: {
count(newValue, oldValue) {
console.log(`The value of count is changed from ${oldValue} to ${newValue}.`);
}
},
methods: {
onClick() {
this.count += 1;
}
},
mounted() {
this.count = this.initialCount;
}
});

new Vue({
el: '#VueApp',
});
</script>
  • Vue.js allows progressive web application development.
  • It offers two-way data binding similar to AngularJS and Virtual DOM and event sourcing similar to React.
  • 40.5% of JavaScript devs are currently using Vue and pledge to keep using it while 34.5% have shown keen interest to use it in future (2nd highest % after Svelte) as per State Of JS 2019 survey. This marks an impressive jump of almost 12% in current users from previous year where the figure stood at 28.8%.
  • In Stack Overflow’s developer survey 2020, Vue was ranked 7th most popular web framework overall and 3rd most popular front end JavaScript framework behind React and Angular.
  • Has equal support for JavaScript and TypeScript.

3. Angular.js

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AngularJS is a JavaScript-based open-source front-end web framework mainly maintained by Google and by a community of individuals and corporations to address many of the challenges encountered in developing single-page applications. It aims to simplify both the development and the testing of such applications by providing a framework for client-side MVC and MVVM architectures, along with components commonly used in rich Internet applications. AngularJS is used as the frontend of the MEAN stack, consisting of MongoDB database, Express.js web application server framework, Angular.js itself, and Node.js server runtime environment.

<div ng-app="myApp" ng-controller="myCtrl">

First Name: <input type="text" ng-model="firstName"><br>
Last Name: <input type="text" ng-model="lastName"><br>
<br>
Full Name: {{firstName + " " + lastName}}

</div>

<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
$scope.firstName= "sanjam";
$scope.lastName= "singh";
});
</script>
  • It has a large eco-system maintained for over a decade.
  • Allows high-quality code generation with a clean coding structure and code consistency.
  • Has great documentation, and its libraries provide massive support for developers
  • 21.9% of JavaScript devs polled are currently using Angular and 9.7% have shown interest to learn and use it in future as per State Of JS 2019 survey. These statistics indicate that Angular is losing the battle against React and Vue for the crown recording a 2% drop in active users when compared to the 2018 survey. Moreover Angular has polled the lowest, a meagre 9.7% in ‘interested to use in future’ category, well behind React, Vue and Svelte.
  • In Stack Overflow’s developer survey 2020, Angular was ranked 7th most popular web framework overall and 2nd most popular front end JavaScript framework just behind React.

Back End JavaScript Frameworks

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credit: dev.to

When it comes to web development, JavaScript is the engine that powers the web. While HTML and CSS handle the styling and data presented on a page, JavaScript governs websites’ scripted behavior, from loading and reloading new page content without totally refreshing the page, to animating page elements, to validating what users input into web forms.

Over time, JavaScript’s popularity has caused a groundswell of frameworks to pop up. It seems that every week brings a new framework for JavaScript developers, each promising to be better than the next. Because millions of websites rely on third-party JavaScript libraries and frameworks, there’s unending demand for such things.

1. Express.js

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credit: dev.to

Express.js is a back end web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs. It has been called the de facto standard server framework for Node.js. TJ Holowaychuk described it as a Sinatra-inspired server that is relatively minimal with many features available as plugins. Express is the back-end component of popular development stacks like the MEAN, MERN or MEVN stack, together with the MongoDB database software and a JavaScript front-end framework or library.

var express = require('express');  
var app = express();
app.get('/', function (req, res) {
res.send('Hello World!!');
});
var server = app.listen(8000, function () {
var host = server.address().address;
var port = server.address().port;
console.log('Example app listening at http://%s:%s', host, port);
});
  • It can be used to design single-page, multi-page and hybrid web applications.
  • It allows to setup middlewares to respond to HTTP Requests.
  • It defines a routing table which is used to perform different actions based on HTTP method and URL.
  • It allows to dynamically render HTML Pages based on passing arguments to templates.
  • 71.6% of JavaScript devs polled have picked Express as their premier choice for best JavaScript framework for backend whereas 12% are inclined to use it in future. Another testament to Express’s popularity is the fact that only 4% of JavaScript developers have never heard of Express before.
  • In Stack Overflow’s developer survey 2020, Express was ranked 5th most popular web framework overall and 2nd best JavaScript framework for server-side behind ASP.NET

2. Next.js

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credit: Mark Colling

Next.js is an open-source React front-end development web framework that enables functionality such as server-side rendering and generating static websites for React based web applications. It is a production-ready framework that allows developers to quickly create static and dynamic JAMstack websites and is used widely by many large companies.Next.js is one of several recommended “toolchains” available when starting a new React app, all of which provide a layer of abstraction to aid in common tasks. Traditional React apps render all their content in the client-side browser, Next.js is used to extend this functionality to include applications rendered on the server side.

export function getServerSideProps() {
return {
redirect: {
destination: 'https://example.com',
permanent: false
}
}
}

The Next framework blurs the line between frontend and backend in such a way that seems a little odd at first, but ultimately makes sharing JavaScript code across the project very easy. This prevents having to duplicate code in different languages for the same task. Querying a datastore and rendering the client side markup that depends on it almost happens in the same component. Once you learn the basic elements of developing with Next, everything becomes quite intuitive.

  • 24.7% of JavaScript devs polled are currently using Next. But what’s even more impressive is the fact that a whopping 43% of devs are interested to give Next a try, the highest interest % for any backend framework.
  • Approx. 34k(live) and 100k(live and historical) websites are using Next acc. to Wappalyzer and BuiltWith statistics as of June 2020.

3. Gatsby.js

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credit: Ahmed Besbes

Avi Wilensky, Founder of Up Hail, noted: “With Gatsby, no server is required since the pages can be built on the developers local machine, and deployed to an object store and CDN (ie. AWS S3 and Cloudfront). The architecture saves on cost, complexity, is secure, and ensures quick performance.”Gatsby is also scalable, with a massive library of over 2,000 plugins available. Based on React and GraphQI, Gatsby is best used to create fairly static websites with services attached (via its plugins, of course). Keep in mind that Gatsby does not perform server-side rendering — this keeps sites built with Gatsby lightning-fast, but it can also be limiting.

module.exports = {
plugins: [
`gatsby-transformer-sharp`,
`gatsby-plugin-sharp`,
{
resolve: `gatsby-source-filesystem`,
options: {
path: `${__dirname}/src/data/`,
},
},
],
}

22% of JavaScript devs polled have used Gatsby and plan to continue using it, while anadditional 35% have shown keen intention to give it a shot in future.

To boost performance, GatsbyJS loads only critical HTML, CSS, JavaScript, and other data. Once loaded, it prefetches resources for other pages you might navigate to. This way, your site loads as fast as possible and user interactions feel seamless.

JavaScript Testing Framework

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JavaScript is also widely used for testing website or web applications. With more and more organizations opting for automation testing, JavaScript testing frameworks are being increasingly used for unit testing, integration testing and End-to-End testing.

1. Jest

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credit: https://zebrunner.com/

Jest JavaScript resting framework with a focus on simplicity. Jest was created by Facebook engineers for its React project. Unit testing is a software testing where individual units (components) of a software are tested. The purpose of unit testing is to validate that each unit of the software performs as designed. A unit is the smallest testable part of any software.Mocking is technique where code parts are replaced by dummy implementations that emulate real code. Mocking helps achieve isolation of tests. Mocking is primarily used in unit testing.In our tests we check that values meet certain conditions. The expect() function gives us a number of matchers that let us validate different things, such as toBe(), toBeFalsy(), or toEqual().

const { add, mul, sub, div } = require('./jest');

test('2 + 3 = 5', () => {
expect(add(2, 3)).toBe(5);
});

test('3 * 4 = 12', () => {
expect(mul(3, 4)).toBe(12);
});

test('5 - 6 = -1', () => {
expect(sub(5, 6)).toBe(-1);
});

test('8 / 4 = 2', () => {
expect(div(8, 4)).toBe(2);
});
  • Jest is considered a very well documented, a fast performing JavaScript testing framework.
  • Jest offers a robust developer tooling with less error-prone code.
  • The framework can also perform visual regression tests by capturing screenshots. When an application is developed using React JS, this feature comes quite handy for preventing UI bugs caused accidentally. It works by recording a screenshot of the rendered component and later comparing it with components rendered in the future. The screenshots can be updated easily if any new feature is added.
  • 61.2% of JavaScript devs polled have picked Jest as their premier choice for JavaScript automated testing framework whereas 22.8% have indicated a curiosity to learn and use it in future. Jest has seen a massive popularity boost between 2016 and 2020 increasing its user base by almost 15 times.

2. Mocha

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credit: Yash Panwer

Mocha.js is an open-source JavaScript test framework that runs on Node.js and in the browser. It’s designed for testing both synchronous and asynchronous code with a very simple interface. Mocha.js runs tests serially to deliver flexible and accurate reporting while mapping uncaught exceptions to their corresponding test cases. Mocha.js provides functions that execute in a specific order and logs the results in the terminal window. It also cleans the state of the software being tested to ensure that test cases run independently of each other.

var sum = require('../sum.js');
var expect = require('chai').expect;

describe('#sum()', function() {

context('without arguments', function() {
it('should return 0', function() {
expect(sum()).to.equal(0)
})
})

context('with number arguments', function() {
it('should return sum of arguments', function() {
expect(sum(1, 2, 3, 4, 5)).to.equal(15)
})

it('should return argument when only one argument is passed', function() {
expect(sum(5)).to.equal(5)
})
})

context('with non-number arguments', function() {
it('should throw error', function() {
expect(function() {
sum(1, 2, '3', [4], 5)
}).to.throw(TypeError, 'sum() expects only numbers.')
})
})

})
  • The application is open source and allows flexibility.
  • It can easily support generators.
  • Since it is old, lots of tutorial and documents are available online.
  • Sequential execution of test cases with flexible reporting.
  • Mocha helps you to easily map exceptions with the relevant test cases.
  • 42% of JavaScript devs have picked Mocha as their favourite JavaScript testing framework whereas 22% of devs have heard about it and would like to learn it in the foreseeable future.

3. Jasmine

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credit: wikipedia

Jasmine is an open-source testing framework for JavaScript. It aims to run on any JavaScript-enabled platform, to not intrude on the application nor the IDE, and to have easy-to-read syntax. It is heavily influenced by other unit testing frameworks, such as ScrewUnit, JSSpec, JSpec, and RSpec.

function helloWorld() {
return 'Hello world!';
}
describe('Hello world', function() {
it('says hello', function() {
expect(helloWorld()).toEqual('Hello world!');
});
});
  • The biggest strength of Jasmine is its compatibility across every framework or libraries of your choice, making it one of the most flexible JavaScript testing frameworks. Whether you want to use Sinon for mocking or Chai for asserting test cases, Jasmine will help you without any difficulties.
  • The community of Jasmine is quite large and you will get all kinds of support which come in the form of libraries, blog posts or video tutorials.
  • With a bigger community, the learning curve is very smooth for Jasmine. You get pretty impressive documentation too.
  • 28.6 % of JavaScript devs have picked Jasmine as their favourite JavaScript testing framework whereas 16.7% of devs have heard about it and would like to learn it in the foreseeable future.

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