Programming TypeScript : Making Your JavaScript Applications Scale

La 4ème de couv. indique : "Any programmer working with a dynamically typed language will tell you how hard it is to scale to more lines of code and more engineers. That's why Facebook, Google, and Microsoft invented gradual static type layers for their dynamically typed JavaScript and Python code. This practical book shows you how one such type layer, TypeScript, is unique among them: it makes programming fun with its powerful static type system. If you're a programmer with intermediate JavaScript experience, author Boris Cherny will teach you how to master the TypeScript language. You'll understand how TypeScript can help you eliminate bugs in your code and enable you to scale your code across more engineers than you could before. In this book, you'll: Start with the basics: Learn about TypeScript's different types and type operators, including what they're for and how they're used. Explore advanced topics: Understand TypeScript's sophisticated type system, including how to safely handle errors and build asynchronous programs. Dive in hands-on: Use TypeScript with your favorite frontend and backend frameworks, migrate your existing JavaScript project to TypeScript, and run your TypeScript application in production" Cover Copyright Table of Contents Preface How This Book Is Organized Style Conventions Used in This Book Using Code Examples O’Reilly Online Learning How to Contact Us Acknowledgments Chapter 1. Introduction Chapter 2. TypeScript: A 10_000 Foot View The Compiler The Type System TypeScript Versus JavaScript Code Editor Setup tsconfig.json tslint.json index.ts Exercises Chapter 3. All About Types Talking About Types The ABCs of Types any unknown boolean number bigint string symbol Objects Intermission: Type Aliases, Unions, and Intersections Arrays Tuples null, undefined, void, and never Enums Summary Exercises Chapter 4. Functions Declaring and Invoking Functions Optional and Default Parameters Rest Parameters call, apply, and bind Typing this Generator Functions Iterators Call Signatures Contextual Typing Overloaded Function Types Polymorphism When Are Generics Bound? Where Can You Declare Generics? Generic Type Inference Generic Type Aliases Bounded Polymorphism Generic Type Defaults Type-Driven Development Summary Exercises Chapter 5. Classes and Interfaces Classes and Inheritance super Using this as a Return Type Interfaces Declaration Merging Implementations Implementing Interfaces Versus Extending Abstract Classes Classes Are Structurally Typed Classes Declare Both Values and Types Polymorphism Mixins Decorators Simulating final Classes Design Patterns Factory Pattern Builder Pattern Summary Exercises Chapter 6. Advanced Types Relationships Between Types Subtypes and Supertypes Variance Assignability Type Widening Refinement Totality Advanced Object Types Type Operators for Object Types The Record Type Mapped Types Companion Object Pattern Advanced Function Types Improving Type Inference for Tuples User-Defined Type Guards Conditional Types Distributive Conditionals The infer Keyword Built-in Conditional Types Escape Hatches Type Assertions Nonnull Assertions Definite Assignment Assertions Simulating Nominal Types Safely Extending the Prototype Summary Exercises Chapter 7. Handling Errors Returning null Throwing Exceptions Returning Exceptions The Option Type Summary Exercises Chapter 8. Asynchronous Programming, Concurrency, and Parallelism JavaScript’s Event Loop Working with Callbacks Regaining Sanity with Promises async and await Async Streams Event Emitters Typesafe Multithreading In the Browser: With Web Workers In NodeJS: With Child Processes Summary Exercises Chapter 9. Frontend and Backend Frameworks Frontend Frameworks React Angular Typesafe APIs Backend Frameworks Summary Chapter 10. Namespaces.Modules A Brief History of JavaScript Modules import, export Dynamic Imports Using CommonJS and AMD Code Module Mode Versus Script Mode Namespaces Collisions Compiled Output Declaration Merging Summary Exercise Chapter 11. Interoperating with JavaScript Type Declarations Ambient Variable Declarations Ambient Type Declarations Ambient Module Declarations Gradually Migrating from JavaScript to TypeScript Step 1: Add TSC Step 2a: Enable Typechecking for JavaScript (Optional) Step 2b: Add JSDoc Annotations (Optional) Step 3: Rename Your Files to .ts Step 4: Make It strict Type Lookup for JavaScript Using Third-Party JavaScript JavaScript That Comes with Type Declarations JavaScript That Has Type Declarations on DefinitelyTyped JavaScript That Doesn’t Have Type Declarations on DefinitelyTyped Summary Chapter 12. Building and Running TypeScript Building Your TypeScript Project Project Layout Artifacts Dialing In Your Compile Target Enabling Source Maps Project References Error Monitoring Running TypeScript on the Server Running TypeScript in the Browser Publishing Your TypeScript Code to NPM Triple-Slash Directives The types Directive The amd-module Directive Summary Chapter 13. Conclusion Appendix A. Type Operators Appendix B. Type Utilities Appendix C. Scoped Declarations Does It Generate a Type? Does It Merge? Appendix D. Recipes for Writing Declaration Files for Third-Party JavaScript Modules Types of Exports Globals ES2015 Exports CommonJS Exports UMD Exports Extending a Module Globals Modules Appendix E. Triple-Slash Directives Internal Directives Deprecated Directives Appendix F. TSC Compiler Flags for Safety Appendix G. TSX Index About the Author Colophon La 4ème de couv. indique : "Any programmer working with a dynamically typed language will tell you how hard it is to scale to more lines of code and more engineers. That's why Facebook, Google, and Microsoft invented gradual static type layers for their dynamically typed JavaScript and Python code. This practical book shows you how one such type layer, TypeScript, is unique among them: it makes programming fun with its powerful static type system. If you're a programmer with intermediate JavaScript experience, author Boris Cherny will teach you how to master the TypeScript language. You'll understand how TypeScript can help you eliminate bugs in your code and enable you to scale your code across more engineers than you could before. In this book, you'll: Start with the basics: Learn about TypeScript's different types and type operators, including what they're for and how they're used. Explore advanced topics: Understand TypeScript's sophisticated type system, including how to safely handle errors and build asynchronous programs. Dive in hands-on: Use TypeScript with your favorite frontend and backend frameworks, migrate your existing JavaScript project to TypeScript, and run your TypeScript application in production"