Book Image

Learning TypeScript 2.x - Second Edition

By : Remo H. Jansen
Book Image

Learning TypeScript 2.x - Second Edition

By: Remo H. Jansen

Overview of this book

TypeScript is an open source and cross-platform statically typed superset of JavaScript that compiles to plain JavaScript and runs in any browser or host. This book is a step-by-step guide that will take you through the use and benefits of TypeScript with the help of practical examples. You will start off by understanding the basics as well as the new features of TypeScript 2.x. Then, you will learn how to work with functions and asynchronous programming APIs. You will continue by learning how to resolve runtime issues and how to implement TypeScript applications using the Object-oriented programming (OOP) and functional programming (FP) paradigms. Later, you will automate your development workflow with the help of tools such as Webpack. Towards the end of this book, you will delve into some real-world scenarios by implementing some full-stack TypeScript applications with Node.js, React and Angular as well as how to optimize and test them. Finally, you will be introduced to the internal APIs of the TypeScript compiler, and you will learn how to create custom code analysis tools.
Table of Contents (17 chapters)


The TypeScript features in this chapter require TypeScript 1.5 or higher and the following options to be enabled in the tsconfig.json file:

"experimentalDecorators": true, 
"emitDecoratorMetadata": true 
As indicated by the experimental decorators compilation flag, the decorator's API is considered experimental. This doesn't mean that it is not ready for production usage. It means that the decorator API is subject to potential breaking changes in the future.

We are also going to need a polyfill for the reflectmetadata API. We need a polyfill because most JavaScript engines don't support this API yet. We can expect that, in the long term, this polyfill will not be required but, currently, we can use the reflect–metadata npm module:

npm install reflect-metadata
The reflect-metadata version was 0.1.12 at the time of...