Function hydrateNode

packages/runtime-core/src/hydration.ts:137–366

(
    node: Node,
    vnode: VNode,
    parentComponent: ComponentInternalInstance | null,
    parentSuspense: SuspenseBoundary | null,
    slotScopeIds: string[] | null,
    optimized = false,
  )

  }

  const hydrateNode = (
    node: Node,
    vnode: VNode,
    parentComponent: ComponentInternalInstance | null,
    parentSuspense: SuspenseBoundary | null,
    slotScopeIds: string[] | null,
    optimized = false,
  ): Node | null => {
    optimized = optimized || !!vnode.dynamicChildren
    const isFragmentStart = isComment(node) && node.data === '['
    const onMismatch = () =>
      handleMismatch(
        node,
        vnode,
        parentComponent,
        parentSuspense,
        slotScopeIds,
        isFragmentStart,
      )

    const { type, ref, shapeFlag, patchFlag } = vnode
    let domType = node.nodeType
    vnode.el = node

    if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
      def(node, '__vnode', vnode, true)
      def(node, '__vueParentComponent', parentComponent, true)
    }

    if (patchFlag === PatchFlags.BAIL) {
      optimized = false
      vnode.dynamicChildren = null
    }

    let nextNode: Node | null = null
    switch (type) {
      case Text:
        if (domType !== DOMNodeTypes.TEXT) {
          // #5728 empty text node inside a slot can cause hydration failure
          // because the server rendered HTML won't contain a text node
          if (vnode.children === '') {
            insert((vnode.el = createText('')), parentNode(node)!, node)
            nextNode = node
          } else {
            nextNode = onMismatch()
          }
        } else {
          if ((node as Text).data !== vnode.children) {
            ;(__DEV__ || __FEATURE_PROD_HYDRATION_MISMATCH_DETAILS__) &&
              warn(
                `Hydration text mismatch in`,
                node.parentNode,
                `\n  - rendered on server: ${JSON.stringify(
                  (node as Text).data,
                )}` +
                  `\n  - expected on client: ${JSON.stringify(vnode.children)}`,
              )
            logMismatchError()