TypeScript is a typed superset of JavaScript with the potential to solve many of the headaches for which JavaScript is famous. But TypeScript has a learning curve of its own, and understanding how to use it effectively takes time and practice. Using the format popularized by Effective C++ and Effective Java (both Addison-Wesley), this practical book features 83 items that give specific advice on what to do and what not to do, and how to think about the language.

Author Dan Vanderkam shows you how to apply each item's advice through concrete examples. This book will help you advance from a beginning or intermediate user familiar with TypeScript basics to an expert who knows how to use the language well.

Updated for TypeScript 5, this second edition includes two new chapters on type-level programming and TypeScript recipes.

• Learn the nuts and bolts of TypeScript's type system
• Use type inference to get full safety with a minimum of type annotations
• Design types to make your code safer and more understandable
• Model complex APIs using generic types and type-level programming
• Understand how dependencies and type declaration files work in TypeScript
• Successfully migrate your JavaScript code base to TypeScript

Table of Contents

Chapter 1. Getting to Know Typescript

Chapter 2. TypeScript's Type System

Chapter 3. Type Inference and Control Flow Analysis

Chapter 4. Type Design

Chapter 5. Unsoundness and the any Type

Chapter 6. Generics and Type-Level Programming

Chapter 7. TypeScript Recipes

Chapter 8. Type Declarations and @types

Chapter 9. Writing and Running Your Code

Chapter 10. Modernization and Migration

Appendix. Item Mapping Between

About the Author

Dan Vanderkam is an independent software developer, formerly at Google and Sidewalk Labs. He is the author of numerous open source JavaScript/TypeScript libraries, including the dygraphs charting library, source-map-explorer, literate-ts, pg-to-ts and crosswalk. He is the author of Effective TypeScript: 62 Ways to Improve Your TypeScript (O'Reilly 2019) and has spoken at numerous TS conferences. He blogs at effectivetypescript.com.