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)
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Decorator overview

In this section of the chapter, we will take a look at the general setup and syntax of decorators, what we need to do to enable them, and how they are applied to classes. We will also show how multiple decorators can be used at the same time, and then discuss the different types of decorators. Finally, this section will take a look at decorator factories, and how we can pass parameters into decorator functions.

Decorator setup

Decorators are an experimental feature of the TypeScript compiler and are supported in ES5 and above. In order to use decorators, we need to enable a compile option in the tsconfig.json file. This option is named experimentalDecorators, and needs to be set to true, as follows:

    "compilerOptions": {
        "target": "es5",
        "module": "commonjs",
        "strict": true,
        "experimentalDecorators": true,
        "skipLibCheck": true...