The built-in Partial and Readonly utilities are shallow. Learn how to write your own DeepReadonly and DeepPartial utilities that penetrate every layer of nested objects by combining Generics, Conditionals, infer, Mapped Types, and Recursion simultaneously.
Take your Mapped Types to the absolute limit. Learn how to compute entirely new string names for keys on the fly using Template Literal Types, and discover how to completely filter out properties by returning never during key mapping.
An in-depth guide to Mapped Type Modifiers in TypeScript. Learn how to preserve, add (+), or strip (-) property modifiers like readonly and ?. We explore how these mapping modifiers power TypeScript’s built-in Partial, Required, and Readonly utility types.
An in-depth guide to Mapped Types in TypeScript. Learn how to use the [K in Union] syntax to iterate over literal unions, transform existing object properties using keyof and Indexed Access, and build strict state validation maps that perfectly mirror domain models.