I am new to functional programming paradigms in JavaScript and trying to learn about partial application in JavaScript.

One exercise that I am working through is a problem that is supposed to be simple - a 3-way sum that is supposed to give the same answers for the following:

partialThreeSum()(a, b, c) === partialThreeSum(a, b)(c) === partialThreeSum(a, b, c) === partialThreeSum(a)(b, c)

'use strict';

function partialThreeSum(a, b, c):
    const threeSum = (a, b, c) => a + b + c;
    return partial(threeSum, a, b, c);

I am having trouble implementing the partial method to allow partial application and return the function with only certain arguments applied. I have looked at the following approaches, all to no avail:

• Implement const partial

const partial = (fn, ...fixedArgs) => (...remainingArgs) => fn(...fixedArgs, ...remainingArgs);

source: https://dev.to/francescoagati/introduction-to-functional-programming-in-javascript-partial-functions-5-4lc3

• Enable partial application

const enablePartialApplication = (fn) => (...args) => {
    if (args.length >= fn.length) return fn(...args);
    return enablePartialApplication(fn.bind(null, ...args));
};

function partialThreeSum(a, b, c) {
    return enablePartialApplication((a, b, c) => a + b + c);
}

source: https://dev.to/ycmjason/how-to-make-functions-partially-applicable-in-javascript--416b

this doesn't really work since sometimes an Anonymous function is returned. Also, I know ahead of time how many arguments the function should take (namely, 3), so I believe there should be a simpler way to implement such that the results of partial application

partialThreeSum()(a, b, c)

partialThreeSum(a, b, c)

partialThreeSum(a, b)(c)

partialThreeSum(a)(b, c)

What is a proper way to implement this for a given number of arguments? I am trying to implement this without any outside libraries (such as lodash) and I am doing use strict, so I cannot use caller, callee, arguments properties. (as shown in https://ada.adrianheine.de/partial-application-js)

Other sources on the internet suggest similar methods, but there is no solution that I can see that can be simply applied to this problem. I am looking to see if there might be an elegant way to accomplish this.