An example of a proxy function

proxy_function.ts

function add(a: number, b: number) {
    return a + b
}
function multiply(a: number, b: number) {
    return a * b
}

function doubler<T extends Function>(fn: T): T {
    return new Proxy(fn, {
        apply(target, self, args) {
            return Reflect.apply(target, self, args) * 2
        }
    })
}

const double_add = doubler(add)
const double_multiply = doubler(multiply)

console.log(double_add(1, 3))
console.log(double_multiply(2, 3))