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

Setting Up E2E tests with Cucumber


Cucumber is an automated test runner that executes tests written in a Domain-Specific Language (DSL) called Gherkin. Gherkin allows you to write tests in plain language, usually in a behavior-driven way, which can be read and understood by anyone, even if they are not technically-minded.

There are many Cucumber implementations for different languages and platforms, such as Ruby, Java, Python, C++, PHP, Groovy, Lua, Clojure, .NET and, of course, JavaScript. The JavaScript implementation is available as an npm package, so let's add it to our project:

$ yarn add cucumber --dev

We are now ready to write the specification for our first feature.

 

 

Features, scenarios, and steps

To use Cucumber, you'd first separate your platform into multiple features; then, within each feature, you'd define scenarios to test for. For us, we can take the "Create user" requirement as one feature, and start breaking it down into scenarios, starting with the following:

  • If the client sends...