Solution for elevator challenge 8

elevator8.js

{
    init: function(elevators, floors) {
        elevators.forEach(elevator => {
            elevator.on('floor_button_pressed', (num) => {
                elevator.goToFloor(num);
            });
        });
        
        floorHandler = (floor) => {
            let closest, idle;
            let distance = Infinity;
            elevators.forEach(e => {
                // check each elevator for the closest one
                let thisDistance = Math.abs(e.currentFloor() - floor.floorNum());
                if (thisDistance < distance) {
                    closest = e;
                    distance = thisDistance;
                }
                // but also check for idle elevators
                if (!e.destinationQueue.length) {
                    idle = e;
                }
            })
            idle ? idle.goToFloor(floor.floorNum()) : closest.goToFloor(floor.floorNum(), true)
        }
        
        floors.forEach(floor => {
            floor.on('up_button_pressed', floorHandler.bind(this, floor))
            floor.on('down_button_pressed', floorHandler.bind(this, floor))
        })
    },
    update: function(dt, elevators, floors) {
        // We normally don't need to do anything here
    }
}