sindresorhus/type-fest: A collection of essential TypeScript types

Type-fest is a comprehensive collection of essential TypeScript utility types created by Sindre Sorhus. The library provides over 100 advanced type utilities organized into categories including basic types, object manipulation, array operations, string transformations, numeric types, and JSON handling. It requires TypeScript 5.9+ and strict mode, offering both deep and shallow versions of common operations like Partial, Readonly, and Pick. The package serves as a reference implementation for advanced TypeScript patterns and can be used as a dependency or by copying individual types.