Functions for getting siblings of a target node

siblings.js

function getSiblings (target) {
  return [
    ...getUntilNull(target, 'previousElementSibling'),
    ...getUntilNull(target, 'nextElementSibling')
  ]
}

/**
 * Collects HtmlElements until null is return from the provided property on target
 * 
 * @params target: HtmlElement
 * @params property: string
 * @returns HtmlElement[]
 */
function getUntilNull (target, property) {
  const collection = []
  let next_target = target[property]
  while (next_target !== null) {
    collection.push(next_target)
    next_target = next_target[property]
  }
  return collection
}