create and object from an array using the given key

objectifyByKey.js

function objectifyByKey(arr, key) {
  if (!Array.isArray(arr)) throw new Error('not an array');
  if (!arr.length) return;

  const reducer = (acc, el) => {
    if (Object.prototype.hasOwnProperty.call(key, el)) {
      return { ...acc, [el[key]]: el };
    }
    return {};
  };

  return  arr.reduce(reducer, {});
}