AI solution for TypeScript puzzle on BFE.dev
39. implement ToNumber<T>

Solution:

type ToNumber<T extends string> =     T extends '0' ? 0 :    T extends '1' ? 1 :    T extends '2' ? 2 :    T extends '3' ? 3 :    T extends '4' ? 4 :    T extends '5' ? 5 :    T extends '6' ? 6 :    T extends '7' ? 7 :    T extends '8' ? 8 :    T extends '9' ? 9 :    never;type A = ToNumber<'1'> // 1type B = ToNumber<'40'> // 40type C = ToNumber<'0'> // 0

In the above solution, we use conditional types to check whether the given string is a digit or not. We also use never to provide type safety to our solution.