Book Image

JavaScript : Functional Programming for JavaScript Developers

By : Ved Antani, Simon Timms, Dan Mantyla
Book Image

JavaScript : Functional Programming for JavaScript Developers

By: Ved Antani, Simon Timms, Dan Mantyla

Overview of this book

JavaScript is a high-level, dynamic, untyped, lightweight, and interpreted programming language and functional programming is a style that emphasizes and enables smarter code that minimizes complexity and increases modularity. It's a way of writing cleaner code through clever ways of mutating, combining, and using functions. And JavaScript provides an excellent medium for this approach. By learning how to expose JavaScript's true identity as a functional language, we can implement web apps that are more powerful, easier to maintain and more reliable. The java script: Functional Programming for JavaScript Developers course will take you on a journey to show how functional programming when combined with other techniques makes JavaScript programming more efficient. The first module Mastering JavaScript, stress on practical aspects of Javascript development like—Functions and Closures, Runtime debugging techniques, project layout, events and DOM processing, build tools, Object-oriented patterns, isomorphism—everything that a modern Javascript project would need. The second module, Mastering JavaScript Design Patterns - Second Edition, will explore how design patterns can help you improve and organize your JavaScript code. You’ll get to grips with creational, structural, and behavioral patterns as you discover how to put them to work in different scenarios. This updated edition will also delve into reactive design patterns and microservices as they are a growing phenomenon in the world of web development. It will also show you some advanced patterns, including dependency injection and live post processing. The third module, Functional Programming in JavaScript, will help you to write real-world applications by utilizing a wide range of functional techniques and styles. It explores the core concepts of functional programming common to all functional languages, with examples of their use in JavaScript.
Table of Contents (6 chapters)

Chapter 12. Patterns for Testing

Throughout this book we've been pushing the idea that JavaScript is no longer a toy language with which we can't do useful things. Real world software is being written in JavaScript right now and the percentage of applications using JavaScript is only likely to grow over the next decade.

With real software comes concerns about correctness. Manually testing software is painful and, weirdly, error-prone. It is far cheaper and easier to produce unit and integration tests that run automatically and test various aspects of the application.

There are countless tools available for testing JavaScript, from test runners to testing frameworks; the ecosystem is a rich one. We'll try to maintain a more or less tool-agnostic approach to testing in this chapter. This book does not concern itself with which framework is the best or friendliest. There are overarching patterns that are common to testing as a whole. It is those that we'll examine...