News for hackers. Stuff that matters.

A comment on TypeScript types can run DOOM [video]. Parent comment

Re:TypeScript types can run DOOM [video] by remolueoend on Wednesday February 26, 2025 @05:18PM (#43188905)
'any' has always been intended as an escape hatch, so no abuse here [1]. The type representing the set of all possible values (the top type in the type lattice) is 'unknown'.

[1] https://www.typescriptlang.org/docs/handbook/2/everyday-type...

[2] https://www.typescriptlang.org/docs/handbook/release-notes/t...

[ Parent | on HN ]
Re:TypeScript types can run DOOM [video] by epolanski on Thursday February 27, 2025 @02:40AM (#43192207)
unknown is not equivalent to any as a type constraint: doesn't work.

https://www.totaltypescript.com/any-considered-harmful#type-...

[ Parent | on HN ]
Re:TypeScript types can run DOOM [video] by matt_kantor on Thursday February 27, 2025 @07:27AM (#43193748)
The widest possible function type is `(...args: never) => unknown`. This is because parameters are contravariant, and `never` is the bottom type. Using that type works in the author's example[0].

I've got an issue open about TypeScript's provided `ReturnType` type which is somewhat related to this[1].

[0]: https://tsplay.dev/Wy0Ogm

[1]: https://github.com/microsoft/TypeScript/issues/55667

[ Parent | on HN ]