Generics in TypeScript: a deep dive

Generics in TypeScript are one of the most powerful, least well-documented features of an extraordinary language. They allow for some of the wizardry you'll have seen in your favourite open-source libraries.

In this module, we'll build our generics knowledge with practical examples taken from real open-source libraries. After completing it, you'll feel confident enough to start experimenting with your own ideas.

Prerequisites

This module is not recommended for beginners. You'll need to have completed:

1. TypeScript for Beginners
2. Intermediate TypeScript - not yet complete
3. Type Transformations - not yet complete

Still, if you want to continue - go ahead!

Work in progress!

This module is a work-in-progress. Exercises may appear out of order, and there will likely be a lot of content inside the FUTURE notes.

You'll still be able to run through the exercises, but expect some bumps along the way!

Quickstart

Clone this repo or open in Gitpod.

# Installs all dependencies
yarn install

# Starts the first exercise
yarn exercise 01

# Runs linting and tests on the solution
yarn solution 01

How to take the course

You'll notice that the course is split into exercises. Each exercise is split into a *.problem.ts and a *.solution.ts.

To take an exercise:

1. Go into *.problem.ts
2. Run yarn exercise 01, where 01 is the number of the exercise you're on.

The exercise script will run TypeScript typechecks and a test suite on the exercise.

This course encourages active, exploratory learning. In the video, I'll explain a problem, and you'll be asked to try to find a solution. To attempt a solution, you'll need to:

1. Check out TypeScript's docs
2. Try to find something that looks relevant.
3. Give it a go to see if it solves the problem.

You'll know if you've succeeded because the tests will pass.

If you succeed, or if you get stuck, unpause the video and check out the *.solution.ts. You can see if your solution is better or worse than mine!

You can run yarn solution 01 to run the tests and typechecking on the solution.

Acknowledgements

Say thanks to Matt on Twitter or by joining his Discord. Consider signing up to his Total TypeScript course.

Reference

yarn exercise 01

Alias: yarn e 01

Run the corresponding *.problem.ts file.

yarn solution 01

Alias: yarn s 01

Run the corresponding *.solution.ts file. If there are multiple, it runs only the first one.