Book Image

Mastering TypeScript - Fourth Edition

By : Nathan Rozentals
Book Image

Mastering TypeScript - Fourth Edition

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)
Other Books You May Enjoy

Exploring decorators

In this section of the chapter, we will work through each of the different types of decorators and experiment with the information that is provided by each decorator function. We will then use what we have learned in order to provide examples of some practical applications of decorators.

Class decorators

We know that in order to define a class decorator, we must define a function that has a single parameter, which is of type Function. Let's take a closer look at this parameter, as follows:

function classConstructorDec(constructor: Function) {
    console.log(`constructor : ${constructor}`);
class ClassWithConstructor {
    constructor(id: number) { }

Here, we have a decorator function named classConstructorDec, which is logging the value of the constructor argument to the console. We have then applied this decorator to a class named ClassWithConstructor. This ClassWithConstructor class has a single constructor function...