Book Image

Mastering TypeScript 3 - Third Edition

By : Nathan Rozentals
Book Image

Mastering TypeScript 3 - Third Edition

By: Nathan Rozentals

Overview of this book

TypeScript is both a language and a set of tools to generate JavaScript. It was designed by Anders Hejlsberg at Microsoft to help developers write enterprise-scale JavaScript. Starting with an introduction to the TypeScript language, before moving on to basic concepts, each section builds on previous knowledge in an incremental and easy-to-understand way. Advanced and powerful language features are all covered, including asynchronous programming techniques, decorators, and generics. This book explores many modern JavaScript and TypeScript frameworks side by side in order for the reader to learn their respective strengths and weaknesses. It will also thoroughly explore unit and integration testing for each framework. Best-of-breed applications utilize well-known design patterns in order to be scalable, maintainable, and testable. This book explores some of these object-oriented techniques and patterns, and shows real-world implementations. By the end of the book, you will have built a comprehensive, end-to-end web application to show how TypeScript language features, design patterns, and industry best practices can be brought together in a real-world scenario.
Table of Contents (16 chapters)
Free Chapter
TypeScript Tools and Framework Options

Using npm and @types

With the release of version 2.0 of the TypeScript compiler, we can now also install declaration files using npm. This means that there is no difference in our toolset in order to install project dependencies, as it is to include the declaration files. As an example, to install the Underscore library as a project dependency, we would type the following:

npm install underscore

And to install the declaration files for Underscore, we can now type the following:

npm install @types/underscore  

Note the @types prefix used within the npm command. This special syntax instructs npm to install the declaration files for Underscore, and is a very subtle but easily remembered syntax.

If we take a look at the package.json file within our project directory, we will note that both the Underscore libraries, and the corresponding type libraries are both registered, as follows...