Function prepareAnchor

packages/runtime-core/src/components/Teleport.ts:568–588

(
  target: RendererElement | null,
  vnode: TeleportVNode,
  createText: RendererOptions['createText'],
  insert: RendererOptions['insert'],
  anchor: RendererNode | null = null,
)

}

function prepareAnchor(
  target: RendererElement | null,
  vnode: TeleportVNode,
  createText: RendererOptions['createText'],
  insert: RendererOptions['insert'],
  anchor: RendererNode | null = null,
) {
  const targetStart = (vnode.targetStart = createText(''))
  const targetAnchor = (vnode.targetAnchor = createText(''))

  // attach a special property, so we can skip teleported content in
  // renderer's nextSibling search
  targetStart[TeleportEndKey] = targetAnchor

  if (target) {
    insert(targetStart, target, anchor)
    insert(targetAnchor, target, anchor)
  }

  return targetAnchor
}