function mergeHook (
  parentVal,
  childVal
) {
  return childVal
    ? parentVal
      ? parentVal.concat(childVal)
      : Array.isArray(childVal)
        ? childVal
        : [childVal]
    : parentVal
}
function mergeHook (
  parentVal,
  childVal
) {
  return childVal
    ? parentVal
      ? parentVal.concat(childVal)
      : Array.isArray(childVal)
        ? childVal
        : [childVal]
    : parentVal
}
function mergeHook ( parentVal , childVal ) { return childVal ? parentVal ? parentVal . concat ( childVal ) : Array . isArray ( childVal ) ? childVal : [ childVal ] : parentVal }
Hooks and props are merged as arrays.
Hooks and props are merged as arrays .
Merge the two values