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

Testing strategies


As it turns out, TDD on the frontend follows a similar approach involving automated UI testing and Unit tests.

Automated UI testing

When we write E2E tests for our API, we first compose our request, send it, and assert that it returns what is expected. In other words, our E2E tests are mimicking how an end user would interact with our API. For the frontend, a user would interact with our application through the user interface (UI). Therefore, the equivalent to E2E testing would be automated UI testing.

UI tests automate the actions that a user of the application would take. For example, if we want to test that an user can register, we'd write a test that:

  • Navigates to the /register page
  • Types in the email
  • Types in the password
  • Presses the Register button
  • Asserts that the user is registered

These tests can be written in Gherkin and run with Cucumber. The actual mimicking of the user action can automate these using Browser Automation Tools like Selenium. For example, when we run...