It appears that sourceOne and sourceTwo are supposed to be Queues (as defined by the class), otherwise I assume the creator would not have written code using the peek method as shown.
You are attempting to pass arrays for the two arguments, but you should instead be passing Queues as arguments.
I am not sure what the intent of the weave function is, but it appears to alternate the values of the original queues into a new one.
const q1 = new Queue();
q1.add(1);
q1.add(3);
q1.add(5);
const q2 = new Queue();
q2.add(2);
q2.add(4);
q2.add(6);
console.log(weave(q1, q2));