Total TypeScript Core Volume is a set of three full TypeScript workshops for the intermediate to expert professional TypeScript programmer that wants to take their skills to the next level. 

The Type Transformations workshop is your guide to TypeScript features and patterns that allow you to manipulate types to produce exactly what you want. As you begin to see how the pieces fit together, you’ll find yourself writing less code that is easier to maintain.

There are over 50 exercises in this workshop, each with a challenge designed to help you learn to wield the power of transforming strings into objects, objects into unions, and everything in between.

<Testimonial author={{name: "Laila Straube"}}>I am sorry but I can not say it in different words. **THIS WORKSHOP IS FU^^ING AMAZING.**</Testimonial>

## Inference Basics 

The TypeScript compiler uses type inference to automatically determine the data type of a value depending on the context in which it is used. We can use several utilities and operators to define our own types more precisely.

## Unions & Indexing Unions

Union types play a key role in the type transformation process. In this section we will work at unions and discriminated unions, as well as how to access their properties with indexed access types. Several of TypeScript’s built-in utility types will also be explored.

## Template Literals 

As of TypeScript 4.1, template literals can be used to power amazing inference on strings. In this section we’ll practice using template literals to help create object types, split strings into tuples, and other useful transformations.

## Type Helpers

Type helpers allow you to manipulate and work with types in a more convenient way. They allow you to set constraints that ensure your types are as you expect while retaining flexibility for reuse. The type helper pattern is important to understand, as it forms the basis of many of TypeScript's core features.

## Conditional Types & Infer 

In this section, we will further explore how to leverage the type helpers pattern, paying special attention to conditional types and inference when working with functions, objects, and Promises.

## Mapped Types 

With TypeScript's mapped types, you can transform any type into and out of objects, unions, and tuples. It's an amazingly flexible tool for creating all sorts of different types. You’ll get practice with all of these, as well as using template literals to dynamically customize your types. One learner wrote they'd been using TS for 2 years and finally understood Mapped Types after this section!

## Challenges

To tie up the previous exercises, we've put together several real-world challenges that will put your Type Transformation skills to the test.

Learn to manipulate types for cleaner, maintainable code with over 50 hands-on exercises, from string manipulation to advanced unions and mapped types.

Type Transformations Workshop

Type Transformations

The Generics workshop is your guide to mastering one of TypeScript's most complex features.

Through dozens of exercises, you'll get to grips with generics from the lowest level, up through examples of how your favorite TS libraries use them.

<Testimonial author={{name: "Tal Faran"}}>Just finished all the Generics sections. Really enjoyed it! It covers realistic problems from our day to day work, and when you reach the end you have strong grasp of how to use generic more efficiently, and in a prettier way that is more accurate of what you wanted to achieve in the first place.</Testimonial>

## Intro to Generics

The best place to start is the start. We'll learn the syntax for assigning generics to functions and classes. We'll learn what's possible with the syntax, and build our very first runtime generic function.

## Passing Type Arguments

TypeScript can infer generics based on arguments passed to functions- but there's an alternative. You can manually pass types as type arguments to functions. We'll cover exactly why this is useful, _when_ it's useful, and what limitations this approach has.

## The Art of Generic Inference

Understanding generics in functions requires deep knowledge of the TypeScript compiler. You usually have multiple options when it comes to representing a generic in a function - and there's often not a right answer. We'll examine exercises which help illuminate these decisions.

## Advanced Generics

There's more to generics than inference. In this section we'll cover generics with conditional types, generic currying, and generics on interfaces. Each come with their own challenges.

## Function Overloads

Sometimes, you don't need a generic. Function overloads provide another method for inferring types from arguments passed to a function. In this section, we'll compare and contrast overloads with generics - and even discuss how they can be combined.

Master TypeScript's generics with exercises from basics to advanced, including conditional types and currying.

TypeScript Generics Workshop

TypeScript Generics

The Advanced Patterns workshop is a primer on several patterns that emerge from TypeScript's primitives. We'll build on the generics and type transformations work we've done so far - extracting methods for architecting them into novel solutions.

Most of these patterns aren't documented by TypeScript - they've been discovered and iterated on by the TypeScript community. Each section focuses on a different pattern via interactive exercises.

**This workshop is not appropriate for beginners.**

## Branded Types

Branded types (sometimes known as nominal types) let you break the rules of TypeScript by 'naming' types. This opens up a _lot_ of possibilities for using the type system to ensure your app's logic is robust.

## Globals

The often-feared global scope is a necessary part of most applications. Whether you're importing a library via CDN that attaches to `window`, or relying on environment variables, you'll need to know how to strongly type the global scope.

## Type Predicates & Assertion Functions

Type predicates and assertion functions give you the power to customize TypeScript's control flow. When used in combination with `if` statements, they can help improve inference and make your code easier to reason about.

## The Builder Pattern

This section builds on the Generics work we did in the previous workshop. We'll use classes and generics to perform ridiculous feats of inference - building up entire data structures in TypeScript without a single type annotation from the user.

## External Libraries

Diving into external libraries is extremely complex. But it's often necessary to debug complicated type errors. Understanding the flow of generics through an external library can be critical to quickly fixing red lines. We'll look at several popular libraries.

## Identity Functions

Sometimes in TypeScript, you just need a function. Some generic inference isn't possible without an identity function. We'll learn when and where to use them, as well as some powerful type helpers to assist their inference.

Intermediate to advanced workshop: Boost app logic, type global scopes, and debug with external libraries.

Advanced Patterns Workshop

Advanced TypeScript Patterns

Matt Pocock is joined by expert developers, library creators, and core team members who share their experience working with TypeScript.

The conversations cover a variety of topics ranging from TypeScript’s history and growth, to its adoption in the workplace and processes for migrating from JavaScript. Of course, there are also plenty of technical deep dives into how TypeScript features are being used behind the scenes of some of the most popular libraries in use today.

Listening to professionals share their real-world experience and workflows is a great way to refine your own skills and processes.

No matter what level of TypeScript experience you have, you’ll come away with ideas and inspiration that will expand your horizons and further your pursuit of TypeScript Wizardry.

## Daniel Rosenwasser: TypeScript’s History and Growth

Daniel Rosenwasser, the program manager for TypeScript, discusses the language’s history and growth, highlighting key moments such as Angular’s adoption of TypeScript and collaborations that have contributed to its success. TypeScript has gained trust from developers by supporting various frameworks and improving features based on community discussion.

## Shaundai Person: Adopting TypeScript at Netflix

Shaundai Person, a senior software engineer at Netflix, discusses her role in building tools and how adopting TypeScript helps keep the codebase organized, reduces errors, and facilitates a more grounded development approach. Shaundai shares insights on involving leadership in decisions, and how strong mentorship on teams leads to more successful TypeScript implementation.

## Priscila Oliveira: Sentry’s Migration to TypeScript

Priscila Oliveira, software engineer at Sentry, outlines the process that led to the error monitoring tool’s successful migration from JavaScript to TypeScript. She shares the process of planning and coordinating the work across timezones, as well as how the team uses GitHub Actions to run checks. By making the move to TypeScript, Sentry was able to decrease frontend bugs for users while enhancing the developer experience for the team.

## Kadi Kraman: The TypeScript Culture at Formidable

Kadi Kraman, Director of Engineering for Mobile Services at Formidable, talks about using TypeScript for building modern web and mobile apps, and how it has become a natural choice due to the company’s robust software culture. Kadi compares TypeScript to Flow and Elm, discussing its flexibility and ease of learning.

## Gabriel Vergnaud: Type and Value Level Mapping in TypeScript

Gabriel Vergnaud, author of Type Level TypeScript and the ts-pattern library, joins Matt to discuss how TypeScript’s type and value levels map together, the importance of inference, and how generic functions can increase code reusability. Gabriel also shares a real-world example of how Datadog uses internal type helpers and conditional types for complex data handling.

## Orta Therox: Building Familiarity with TypeScript

Former TypeScript core team member Orta Therox offers insights into how developers can become more familiar and productive with TypeScript. Covering topics such as generics and compiler flags, Orta also emphasizes the importance of consulting resources like the TypeScript Handbook when feeling stuck.

## Tejas Kumar: TypeScript for Bulletproof Apps

TypeScript and React expert Tejas Kumar shares his positive experience with TypeScript and its benefits in building “bulletproof” apps. Matt and Tejas discuss integrating TypeScript into the development workflow beyond the IDE, the future of TypeScript, and the added safety provided by using Zod.

## Mark Erikson: Avoiding Breaking Changes & Improving Maintainability

Redux maintainer Mark Erikson talks about his journey learning TypeScript and the challenges he faced refactoring large parts of Redux codebases. Mark also shares his experience improving the TypeScript types of the Reselect library, reducing duplication, and enhancing maintainability.

## Tanner Linsley: Exploring Generics in React Query

Tanner Linsley, creator of the TanStack collection of open-source libraries, shares his experience building React Query with TypeScript. Tanner discusses the importance of generics for customizable data handling and provides tips for effective usage, despite their potential complexity.

## Colin McDonnell: Design Choices Behind Zod

In this interview, Colin McDonnell, the creator of the TypeScript validation library Zod, discusses the motivations and design choices behind the project. Colin explains the importance of deeply understanding generics and conditionals for ensuring type safety, and shares code walkthroughs to demonstrate Zod’s inner workings.

## Alex “KATT” Johansson: Developing tRPC

Alex Johansson, the creator of the popular TypeScript library tRPC, shares challenges faced during development, including complex generics, the builder pattern, and the importance of types to the API. Alex also leads a walkthrough of the code and design decisions behind the tRPC library.

Legacy Core Volume (v1)

Total TypeScript Core Volume is a set of three full TypeScript workshops for the intermediate to expert professional TypeScript programmer that wants to take their skills to the next level.

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Legacy Core Volume (v1)

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