TS.07.01 Senior

Recursive types

Comes up in: Coding

This concept is being written. It gets the full five steps — explanation, predict, interview angle, practice with tests, and review cards. Here is exactly what it will cover, so you can study it elsewhere in the meantime.

What it covers

JSON type
DeepPartial, DeepReadonly
recursion limits and tail-recursive conditional types
performance cost

Words you will know

recursive typeinstantiation depth

What you will practise

DeepPartial, Paths<T> ("a.b.c" union)

Interview questions this answers

Write a DeepReadonly<T> type.
Create a type for all dot-separated paths of an object.
How do you test types?
Type a pipe function with any number of steps (or explain why it is hard).