TypeScript Application Security

The book "TypeScript Application Security" is a practical guide that helps developers of all levels create web applications in TypeScript that are protected from attacks. Unlike general cybersecurity books, this material focuses specifically on the features of TypeScript and its ecosystem: strict typing, compilation to JavaScript, and interaction with modern frameworks (React, Angular, Node.js).

The author systematically breaks down the most critical vulnerabilities: cross-site scripting (XSS), cross-site request forgery (CSRF), SQL injections, authentication and session management issues. Special attention is paid to type safety — how TypeScript helps prevent errors at compile time and what "holes" still remain at runtime. You will learn how to properly use strict typing to protect against implicit conversions and data leaks.

The book consists of four parts:

• TypeScript Security Basics — threat model, secure by design principles, configuring strict compiler rules.
• Web Attack Protection — XSS, CSRF, Clickjacking, injections, safe DOM and API handling.
• Server-Side Code Security — protecting Node.js applications, secure secret storage, input validation, DoS protection.
• Infrastructure and Delivery — secure builds, dependency checking (npm audit), CI/CD with security checks, logging and monitoring.

Each chapter contains real code examples (before and after fixes), practical exercises, and audit checklists. You will learn to:

• Use TypeScript to automatically prevent entire classes of vulnerabilities.
• Properly handle user input and avoid injections.
• Configure Content Security Policy and other security headers.
• Work with secure authentication (JWT, OAuth2) and access control.
• Conduct code reviews with a focus on security.

The book is suitable for both beginner developers just learning TypeScript and experienced engineers looking to systematize their knowledge of security. A basic understanding of TypeScript and web development is sufficient to read it. All examples are available in the repository and tested on current TypeScript versions (4.x and 5.x).

"TypeScript Application Security" is not just theory, but a ready-made toolkit for protecting your code from real threats. Make security a part of your development process.