[incomplete][idea] Code Wars - Chained - https://www.codewars.com/kata/54c27ef1fb7da0118600046a/train/javascript

main.js

function chain(fns) {
  let c = {};
  let toEx = [];
  
  for (let fn in fns) {
    this[fn] = fns[fn];
    c.[fn] = function () {
      toEx.push({ [fn]: arguments });
    }
  }
  
  return {
    // sum, other functions
    execute: function () {
      
    }
  }
}

test.js

function sum(x, y) {
  return x + y;
}

function double(x) {
  return sum(x, x);
}

function minus (x, y) {
  return x - y;
}

function addOne(x) {
  return sum(x, 1);
}

let c = chain({sum, double, minus, addOne});
console.log(c.sum);
c.sum(a, b) // {  }