/**

* TODO:

* Testing

* Debugging

*/

function toString(list) {

let head = list;

let str = '';

while (head !== null) {

str = `${head.value}${str}`;

head = head.next;

}

return str;

}

function sumLists(list1, list2) {

let num1 = parseInt(toString(list1), 10);

let num2 = parseInt(toString(list2), 10);

return num1 + num2;

}

function makeList(values = []) {

let current = {

value: values.shift(),

next: null

};

const head = current;

values.forEach(value => {

next = {

value,

next: null

}

current.next = next;

current = next;

});

return head;

}

function testSumLists(values1, values2) {

let list1 = makeList(values1);

let list2 = makeList(values2);

let sum = sumLists(list1, list2);

console.log(sum);

}

testSumLists([1], [2]); // 3

testSumLists([1,2], [2,1]); // 33

testSumLists([1,2,3], [4,5]); // 375