Book Image

Mastering TypeScript - Fourth Edition

By : Nathan Rozentals
4.7 (3)
Book Image

Mastering TypeScript - Fourth Edition

4.7 (3)
By: Nathan Rozentals

Overview of this book

TypeScript is both a language and a set of tools to generate JavaScript, designed by Anders Hejlsberg at Microsoft to help developers write enterprise-scale JavaScript. Mastering Typescript is a golden standard for budding and experienced developers. With a structured approach that will get you up and running with Typescript quickly, this book will introduce core concepts, then build on them to help you understand (and apply) the more advanced language features. You’ll learn by doing while acquiring the best programming practices along the way. This fourth edition also covers a variety of modern JavaScript and TypeScript frameworks, comparing their strengths and weaknesses. You'll explore Angular, React, Vue, RxJs, Express, NodeJS, and others. You'll get up to speed with unit and integration testing, data transformation, serverless technologies, and asynchronous programming. Next, you’ll learn how to integrate with existing JavaScript libraries, control your compiler options, and use decorators and generics. By the end of the book, you will have built a comprehensive set of web applications, having integrated them into a single cohesive website using micro front-end techniques. This book is about learning the language, understanding when to apply its features, and selecting the framework that fits your real-world project perfectly.
Table of Contents (19 chapters)
17
Other Books You May Enjoy
18
Index

HTML-based tests

Jest uses a library named jsdom to allow for testing HTML elements and interactions. Jsdom is not an actual browser; it is a library that implements the JavaScript DOM API, and can, therefore, simulate a full-blown browser experience. The benefit of using jsdom is in the speed at which we can run our tests, and the fact that we do not have to provide an environment that can run a full browser. Running a full internet browser generally assumes that the tests are running on a standard computer, and as such, has an actual screen. This means that virtual machines that run tests must be configured with a screen, and adds the extra requirements of having a screen driver that can run at the required resolution.

We can install the jsdom library using npm as follows:

npm install jsdom --save-dev 

While we are at it, let's install the jquery library as well:

npm install jquery

And the @types declaration files for both libraries as follows:

npm...