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
Dedication
Packt Upsell
Contributors
Preface
Free Chapter
1
The Importance of Good Code
Index

Chapter 7. Modularizing Our Code

In the previous chapter, we followed a TDD workflow and implemented the first endpoint of our API—the Create User endpoint. We wrote our End-to-End (E2E) tests in Gherkin, ran them using the Cucumber test runner, and used them to drive development. Everything works, but all the code is contained within a single, monolithic file (src/index.js); this is not modular and makes our project hard to maintain, especially as we add more endpoints. Therefore, in this chapter, we will be separating our application code into smaller modules. This will allow us to write unit and integration tests for them in Chapter 8Writing Unit/Integration Tests.

By following this chapter, you will be able to do the following:

  • Break down large blocks of code into smaller modules
  • Define and validate JavaScript objects with JSON Schema and Ajv