Book Image

Building Enterprise JavaScript Applications

By : Daniel Li
Book Image

Building Enterprise JavaScript Applications

By: Daniel Li

Overview of this book

With the over-abundance of tools in the JavaScript ecosystem, it's easy to feel lost. Build tools, package managers, loaders, bundlers, linters, compilers, transpilers, typecheckers - how do you make sense of it all? In this book, we will build a simple API and React application from scratch. We begin by setting up our development environment using Git, yarn, Babel, and ESLint. Then, we will use Express, Elasticsearch and JSON Web Tokens (JWTs) to build a stateless API service. For the front-end, we will use React, Redux, and Webpack. A central theme in the book is maintaining code quality. As such, we will enforce a Test-Driven Development (TDD) process using Selenium, Cucumber, Mocha, Sinon, and Istanbul. As we progress through the book, the focus will shift towards automation and infrastructure. You will learn to work with Continuous Integration (CI) servers like Jenkins, deploying services inside Docker containers, and run them on Kubernetes. By following this book, you would gain the skills needed to build robust, production-ready applications.
Table of Contents (26 chapters)
Title Page
Copyright and Credits
Packt Upsell
Free Chapter
The Importance of Good Code

Evolution of the web application

When you type a URL, such as, into your browser, what actually happens? First, the browser would send a request to one of Example Corp's servers, which retrieves the resource requested (for example, an HTML file), and sends it back to the client:

The browser then parses the HTML, retrieves all the files the web page depends on, such as CSS, JavaScript, and media files, and renders it onto the page.

The browser consumes flat, one-dimensional texts (HTML, CSS) and parses them into tree-like structures (DOM, CSSOM) before rendering it onto the page.

This scheme is known as the client-server model. In this model, most of the processing is handled server-side; the client's role is limited to simple and superficial uses, such as rendering the page, animating menus and image carousels, and providing event-based interactivity.

This model was popular in the 1990s and 2000s, when web browsers were not very powerful. Creating entire applications with JavaScript...