TypeScript Application Security: From Vulnerabilities to Protection

Modern web development in TypeScript requires not only deep knowledge of the language, but also an understanding of security principles. The book "Security of TypeScript Applications" is a practical guide that will help you create reliable and secure applications, ranging from simple scripts to complex enterprise systems.

The book covers key security aspects that are relevant specifically for TypeScript and the JavaScript ecosystem. You will learn how to protect your application from common vulnerabilities: cross-site scripting (XSS), SQL injections, cross-site request forgery (CSRF), data leaks due to improper input handling, and typing errors.

Special attention is paid to practical protection methods:

• Safe work with types — how to use TypeScript's strict typing to prevent errors that lead to vulnerabilities.
• Data validation and sanitization — tools and libraries (Zod, io-ts, validator.js) for checking incoming user data.
• Protection against XSS — escaping methods, Content Security Policy (CSP), and safe work with the DOM.
• Server-side security — protecting Node.js/Express applications written in TypeScript from injections and attacks.
• Authentication and authorization — implementing JWT, OAuth2, protection against brute force and session attacks.
• Working with external dependencies — auditing npm packages, detecting vulnerabilities using Snyk and npm audit.
• Security testing — writing unit tests and integration tests to check for vulnerabilities.

The book is intended for developers already familiar with TypeScript, but who wish to deepen their knowledge in the field of security. It will be useful both for frontend developers working with React, Angular, or Vue, and for backend developers using Node.js. Each chapter contains practical code examples that can be immediately applied in a project.

After reading the book, you will be able to:

• Identify and eliminate typical vulnerabilities in TypeScript applications.
• Configure static analysis tools and security linters (ESLint with plugins, TypeScript strict mode).
• Develop an architecture that is resistant to attacks.
• Conduct a security audit of your code and dependencies.
• Write secure code from the start, without sacrificing performance.

The book "Security of TypeScript Applications" is your reliable assistant in creating secure and fault-tolerant web applications. Regardless of whether you are working on a startup or a large enterprise project, the knowledge from this book will help you avoid costly mistakes and protect user data.