Make it beautiful with strict rules!

fp-curry.js

/* Rules:
1. No If Statements (only ternary operators are allowed)
2. Function has 0 or 1 Argument
3. Function is a Single Return (can be as big as you like)
4. No Assignments in Function
5. No Side-Effects
6. No Shared Variables
*/

// version #1
function curry(fn) {
    return function f1(...args) {
        return args.length >= fn.length
            ? fn(...args)
            : (...moreArgs) => f1(...[...args, ...moreArgs])
    }
}

// version #2

function curry(fn) {
    const arity = fn.length
    return function f1(...args) {
        if (args.length >= arity) {
            return fn(...args)
        } else {
            return function f2(...moreArgs) {
                const newArgs = args.concat(moreArgs)
                return f1(...newArgs)
            }
        }
    }
}

Stylin'