Book Image

The TypeScript Workshop

By : Ben Grynhaus, Jordan Hudgens, Rayon Hunte, Matt Morgan, Vekoslav Stefanovski
5 (1)
Book Image

The TypeScript Workshop

5 (1)
By: Ben Grynhaus, Jordan Hudgens, Rayon Hunte, Matt Morgan, Vekoslav Stefanovski

Overview of this book

By learning TypeScript, you can start writing cleaner, more readable code that’s easier to understand and less likely to contain bugs. What’s not to like? It’s certainly an appealing prospect, but learning a new language can be challenging, and it’s not always easy to know where to begin. This book is the perfect place to start. It provides the ideal platform for JavaScript programmers to practice writing eloquent, productive TypeScript code. Unlike many theory-heavy books, The TypeScript Workshop balances clear explanations with opportunities for hands-on practice. You’ll quickly be up and running building functional websites, without having to wade through pages and pages of history and dull, dry fluff. Guided exercises clearly demonstrate how key concepts are used in the real world, and each chapter is rounded off with an activity that challenges you to apply your new knowledge in the context of a realistic scenario. Whether you’re a hobbyist eager to get cracking on your next project, or a professional developer looking to unlock your next promotion, pick up a copy and make a start! Whatever your motivation, by the end of this book, you’ll have the confidence and understanding to make it happen with TypeScript.
Table of Contents (16 chapters)
Preface

Unit Testing with ts-jest

Large systems require constant testing to ensure they are correct. This is where unit testing comes in. Some of the biggest software projects in the world have hundreds of millions of lines of code and thousands of features and views. It's simply not possible to manually test every feature. This is where unit tests come in. Unit tests test the smallest unit of code, often a single statement or function, and give us quick feedback if we've done something to change the behavior of an application. Short feedback cycles are a developer's best friend and unit tests are one of the most powerful tools to achieve them.

There are many testing frameworks that can help us to unit test our code. Jest is a popular testing framework from Facebook. You may also come across other frameworks, such as Jasmine, Mocha, or Ava. Jest is a "batteries included" framework that will seem familiar to users of those other frameworks as it has tried to incorporate...