O-log-n.js

const insert = (fn = (a, b) => a < b, item, list = []) => {
    if (!list.length) {
        return [item];
    }
    if (list.length === 1) {
        return fn(item, list[0]) ? [item, list[0]] : [list[0], item];
    }
    let min = 0;
    let max = list.length - 1;
    while (true) {
        if (max < min) {
            return list.slice(0, min).concat([item], list.slice(min));
        }
        const currIndex = Math.floor((min + max) / 2);
        const currItem = list[currIndex];
        const sort = fn(item, currItem);
        if (sort) {
            max = currIndex - 1;
        }
        if (!sort) {
            min = currIndex + 1;
        }
    }
};