Comment by WorldMaker

In addition to exploring `satisfies` as a better `as` (compile checks, that don't assert), you may also be looking for `is` aka Type Guards (runtime checks that assert types).

If you have a validator function `function isSomeSpecificType(obj: unknown): boolean` you make it a Type Guard by changing the return type to be the type assertion you need: `function isSomeSpecificType(obj: unknown): obj is SomeSpecificType`. Typescript's narrowing is pretty good about using Type Guards to good advantage.