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

Structuring our test files

Next, we are going to write our unit tests, but where should we put them? There are generally two approaches:

  • Placing all tests for the application in a top-level test/ directory
  • Placing the unit tests for a module of code next to the module itself, and using a generic test directory only for application-level integration tests (for example, testing integration with external resources such as databases)

The second approach (as shown in the following example) is better as it keeps each module truly separated in the filesystem:

$ tree
├── src
│   └── feature
│       ├── index.js
│       └── index.unit.test.js
└── test
    ├── db.integration.test.js
    └── app.integration.test.js

Furthermore, we're going to use the .test.js extension to indicate that a file contains tests (although using .spec.js is also a common convention). We will be even more explicit and specify the type of test in the extension itself; that is, using unit.test.js for unit test, andintegration...