Pick ordered values snippet

pick-ordered-values.js

/**
 * Pick ordered values.
 *
 * @example
 * pickOrderedValues(
 *   ['wat', 'silly'],
 *   { silly: 100, thing: 200, wat: 300 }
 * );
 * // => [300, 100]
 *
 * @param {string[]} order Collection of properties to pick from `values`
 * @param {Object} values
 * @param {boolean} [strict=false] Throw an error if `values` is missing a
 * @returns {Array}
 */
function pickOrderedValues(order, values, strict) {
  if (!Array.isArray(order)) {
    throw new Error('Expected order to be an array');
  }
  if (!(values instanceof Object)) {
    throw new Error('Expected values to be an object');
  }

  if (strict) {
    const valuesKeys = Object.keys(values);

    order.forEach(item => {
      if (valueKeys.indexOf(item) === -1) {
        throw new Error(`Values missing property ${item}`);
      }
    });
  }

  return order.reduce((accumulator, prop) => {
    return accumulator.concat(values[prop]);
  }, []);
}