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TypeScript Gymnastics: Why Are They So Powerful for You?

Microsoft MVP, Google Developer Expert, Senior Software Developer at Nearform and JS enthusiastic.

In TypeScript’s type system is more than just a tool for catching errors—it’s a way to solve complex problems with clean and reliable code. In this talk, we’ll dive into advanced TypeScript techniques like mapped types, conditional types, and generics to handle even the trickiest type challenges.

You’ll see how these techniques can help you extract, transform, and validate data types while keeping your code simple and maintainable. These "TypeScript gymnastics" aren’t just for show—they’re practical skills that make your systems stronger and easier to work with.

Come learn how to take full advantage of TypeScript’s flexibility and power to build solutions that are as smart as they are safe.

This talk has been presented at JSNation 2025, check out the latest edition of this JavaScript Conference.

FAQ

The speaker is Luca Del Pupo, an Estonian Software Engineer at Pneumformal, specializing in JavaScript and TypeScript.

The talk focuses on advanced features of TypeScript, explaining how to improve code stickiness and make TypeScript code more strict.

Understanding where JavaScript ends and TypeScript begins is crucial for working with advanced TypeScript features and ensuring proper integration of both languages in your codebase.

TypeScript allows you to define specific literal types for state management, ensuring that state values are restricted to specified options like 'starting', 'running', 'arriving', or 'retiring'.

Template literal types in TypeScript are used to create new types from existing ones by combining them in specific formats, such as creating runner statuses by combining runner names with states.

TypeScript uses conditional types with a pattern matching approach, utilizing the 'extends' keyword to determine if certain conditions are met and then returning specific types based on these conditions.

Some built-in TypeScript utilities mentioned include 'ReturnType', 'Partial', 'Required', 'Readonly', 'Extract', 'Exclude', 'Pick', and 'Omit', which help in manipulating and extracting type information.

Using TypeScript can significantly improve developer experience by reducing errors, guiding feature creation, and providing a more structured approach to code development.

Challenges include the need for extensive knowledge, time to implement, and potential headaches when understanding complex TypeScript functionalities.

Luca advises not to forget to create tests for your codebase, as tests serve a different purpose than types, and highlights the importance of balancing time investment with the benefits of using TypeScript.

typescript web standards

Luca Del Puppo

23 min

16 Jun, 2025

Comments

Video Summary and Transcription

The Talk delves into TypeScript, highlighting its introduction, differences from JavaScript, and providing code examples. It emphasizes the significance of strict typing in TypeScript, showcasing the use of literal types and union types for precise type modeling. The discussion also covers template literal types for creating combined types and precise type matching, as well as conditional handling without if statements and function type inference. Furthermore, it explores looping, recursion, object type manipulation, key manipulation, mapper type, and TypeScript utility types for efficient property management and type manipulation.

Available in Español: TypeScript Gymnastics: ¿Por Qué Son Tan Poderosos para Ti?

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