recursive, functional dropWhile & sort

dropWhile.js

const dropwhile = (predicate, list) => {
  return list.reduce((acc, item) => {
    if (acc.drop) {
      const drop = predicate(item);
      const list = drop ? acc.list : [...acc.list, item];
      return { drop, list };
    }
    return {drop: false, list: [...acc.list, item]} 
  }, {drop: true, list: []}).list;
};

const dropwhile2 = (pred,list) => {
  const dw = (l) => {
    if (!l.length) return l;
    const [item, ...rest] = l;
    if(pred(item)) {
      return dw(rest);
    }
    return l;
  };
  return dw(list);
};


const sort = (unsorted) => {
  const insert = (n, array) => {
    if (!array.length) return [n]
    const [x, ...xs] = array;
    if (n <= x) {
      return [n,...array];
    }
    return [x, ...insert(n, xs)];
  };
  const walk = (a, b = []) => {
    if (!a.length) return b;
    const [x, ...xs] = a;
    return walk(xs, insert(x, b));
  };
  return walk(unsorted);
};

console.log(sort([7,3,6,1,8,4,2,5]));