Shift an array left and right

LRShift.js

let items = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l'];

function shift({array, direction, amount}) {
  let arr = array.slice(0);
  let times = amount > arr.length ? amount % arr.length : amount;
  let result = arr;
  let modifier = direction === 'left' ? arr.length - times : times;
  
  result = arr.concat(arr.splice(0, modifier));
  
  return result;
}

console.clear();

console.log('shift right', shift({array: items, direction: 'left', amount: 1}));
console.log('shift left', shift({array: items, direction: 'right', amount: 1}));