For this specific question, the focus is on typings.
Imagine we have a basic generic function type:
type Fn<T> = (input: T) => boolean
The goal is to create a function that, when given an object type as a parameter, will accept an object with the same structure as the generic argument (same keys). However, the values should be of type Fn, where the fields' types match the generic argument.
Here's an example:
type Val = {
a: string
b: number
}
If we pass this type Val as a generic argument to function f, it should receive an object like this:
f<Val>({
a: (input: string) => true, // Fn<string>
b: (input: number) => false, // Fn<number>
c: (input: boolean) => false // Compiler error
// a: (input: number) => false -> would also be a compile error
})
How can we define the type of the function's argument here? Is it achievable in TypeScript?
function f<T>(input: ???): void {
//...
}