switch to vuepress

1 files changed, 787 insertions, 0 deletions

diff --git a/node_modules/vue/src/core/vdom/patch.js b/node_modules/vue/src/core/vdom/patch.js
new file mode 100644
index 00000000..9f3bcc65
--- /dev/null
+++ b/node_modules/vue/src/core/vdom/patch.js
@@ -0,0 +1,787 @@
+/**
+ * Virtual DOM patching algorithm based on Snabbdom by
+ * Simon Friis Vindum (@paldepind)
+ * Licensed under the MIT License
+ * https://github.com/paldepind/snabbdom/blob/master/LICENSE
+ *
+ * modified by Evan You (@yyx990803)
+ *
+ * Not type-checking this because this file is perf-critical and the cost
+ * of making flow understand it is not worth it.
+ */
+
+import VNode, { cloneVNode } from './vnode'
+import config from '../config'
+import { SSR_ATTR } from 'shared/constants'
+import { registerRef } from './modules/ref'
+import { traverse } from '../observer/traverse'
+import { activeInstance } from '../instance/lifecycle'
+import { isTextInputType } from 'web/util/element'
+
+import {
+  warn,
+  isDef,
+  isUndef,
+  isTrue,
+  makeMap,
+  isRegExp,
+  isPrimitive
+} from '../util/index'
+
+export const emptyNode = new VNode('', {}, [])
+
+const hooks = ['create', 'activate', 'update', 'remove', 'destroy']
+
+function sameVnode (a, b) {
+  return (
+    a.key === b.key && (
+      (
+        a.tag === b.tag &&
+        a.isComment === b.isComment &&
+        isDef(a.data) === isDef(b.data) &&
+        sameInputType(a, b)
+      ) || (
+        isTrue(a.isAsyncPlaceholder) &&
+        a.asyncFactory === b.asyncFactory &&
+        isUndef(b.asyncFactory.error)
+      )
+    )
+  )
+}
+
+function sameInputType (a, b) {
+  if (a.tag !== 'input') return true
+  let i
+  const typeA = isDef(i = a.data) && isDef(i = i.attrs) && i.type
+  const typeB = isDef(i = b.data) && isDef(i = i.attrs) && i.type
+  return typeA === typeB || isTextInputType(typeA) && isTextInputType(typeB)
+}
+
+function createKeyToOldIdx (children, beginIdx, endIdx) {
+  let i, key
+  const map = {}
+  for (i = beginIdx; i <= endIdx; ++i) {
+    key = children[i].key
+    if (isDef(key)) map[key] = i
+  }
+  return map
+}
+
+export function createPatchFunction (backend) {
+  let i, j
+  const cbs = {}
+
+  const { modules, nodeOps } = backend
+
+  for (i = 0; i < hooks.length; ++i) {
+    cbs[hooks[i]] = []
+    for (j = 0; j < modules.length; ++j) {
+      if (isDef(modules[j][hooks[i]])) {
+        cbs[hooks[i]].push(modules[j][hooks[i]])
+      }
+    }
+  }
+
+  function emptyNodeAt (elm) {
+    return new VNode(nodeOps.tagName(elm).toLowerCase(), {}, [], undefined, elm)
+  }
+
+  function createRmCb (childElm, listeners) {
+    function remove () {
+      if (--remove.listeners === 0) {
+        removeNode(childElm)
+      }
+    }
+    remove.listeners = listeners
+    return remove
+  }
+
+  function removeNode (el) {
+    const parent = nodeOps.parentNode(el)
+    // element may have already been removed due to v-html / v-text
+    if (isDef(parent)) {
+      nodeOps.removeChild(parent, el)
+    }
+  }
+
+  function isUnknownElement (vnode, inVPre) {
+    return (
+      !inVPre &&
+      !vnode.ns &&
+      !(
+        config.ignoredElements.length &&
+        config.ignoredElements.some(ignore => {
+          return isRegExp(ignore)
+            ? ignore.test(vnode.tag)
+            : ignore === vnode.tag
+        })
+      ) &&
+      config.isUnknownElement(vnode.tag)
+    )
+  }
+
+  let creatingElmInVPre = 0
+
+  function createElm (
+    vnode,
+    insertedVnodeQueue,
+    parentElm,
+    refElm,
+    nested,
+    ownerArray,
+    index
+  ) {
+    if (isDef(vnode.elm) && isDef(ownerArray)) {
+      // This vnode was used in a previous render!
+      // now it's used as a new node, overwriting its elm would cause
+      // potential patch errors down the road when it's used as an insertion
+      // reference node. Instead, we clone the node on-demand before creating
+      // associated DOM element for it.
+      vnode = ownerArray[index] = cloneVNode(vnode)
+    }
+
+    vnode.isRootInsert = !nested // for transition enter check
+    if (createComponent(vnode, insertedVnodeQueue, parentElm, refElm)) {
+      return
+    }
+
+    const data = vnode.data
+    const children = vnode.children
+    const tag = vnode.tag
+    if (isDef(tag)) {
+      if (process.env.NODE_ENV !== 'production') {
+        if (data && data.pre) {
+          creatingElmInVPre++
+        }
+        if (isUnknownElement(vnode, creatingElmInVPre)) {
+          warn(
+            'Unknown custom element: <' + tag + '> - did you ' +
+            'register the component correctly? For recursive components, ' +
+            'make sure to provide the "name" option.',
+            vnode.context
+          )
+        }
+      }
+
+      vnode.elm = vnode.ns
+        ? nodeOps.createElementNS(vnode.ns, tag)
+        : nodeOps.createElement(tag, vnode)
+      setScope(vnode)
+
+      /* istanbul ignore if */
+      if (__WEEX__) {
+        // in Weex, the default insertion order is parent-first.
+        // List items can be optimized to use children-first insertion
+        // with append="tree".
+        const appendAsTree = isDef(data) && isTrue(data.appendAsTree)
+        if (!appendAsTree) {
+          if (isDef(data)) {
+            invokeCreateHooks(vnode, insertedVnodeQueue)
+          }
+          insert(parentElm, vnode.elm, refElm)
+        }
+        createChildren(vnode, children, insertedVnodeQueue)
+        if (appendAsTree) {
+          if (isDef(data)) {
+            invokeCreateHooks(vnode, insertedVnodeQueue)
+          }
+          insert(parentElm, vnode.elm, refElm)
+        }
+      } else {
+        createChildren(vnode, children, insertedVnodeQueue)
+        if (isDef(data)) {
+          invokeCreateHooks(vnode, insertedVnodeQueue)
+        }
+        insert(parentElm, vnode.elm, refElm)
+      }
+
+      if (process.env.NODE_ENV !== 'production' && data && data.pre) {
+        creatingElmInVPre--
+      }
+    } else if (isTrue(vnode.isComment)) {
+      vnode.elm = nodeOps.createComment(vnode.text)
+      insert(parentElm, vnode.elm, refElm)
+    } else {
+      vnode.elm = nodeOps.createTextNode(vnode.text)
+      insert(parentElm, vnode.elm, refElm)
+    }
+  }
+
+  function createComponent (vnode, insertedVnodeQueue, parentElm, refElm) {
+    let i = vnode.data
+    if (isDef(i)) {
+      const isReactivated = isDef(vnode.componentInstance) && i.keepAlive
+      if (isDef(i = i.hook) && isDef(i = i.init)) {
+        i(vnode, false /* hydrating */, parentElm, refElm)
+      }
+      // after calling the init hook, if the vnode is a child component
+      // it should've created a child instance and mounted it. the child
+      // component also has set the placeholder vnode's elm.
+      // in that case we can just return the element and be done.
+      if (isDef(vnode.componentInstance)) {
+        initComponent(vnode, insertedVnodeQueue)
+        if (isTrue(isReactivated)) {
+          reactivateComponent(vnode, insertedVnodeQueue, parentElm, refElm)
+        }
+        return true
+      }
+    }
+  }
+
+  function initComponent (vnode, insertedVnodeQueue) {
+    if (isDef(vnode.data.pendingInsert)) {
+      insertedVnodeQueue.push.apply(insertedVnodeQueue, vnode.data.pendingInsert)
+      vnode.data.pendingInsert = null
+    }
+    vnode.elm = vnode.componentInstance.$el
+    if (isPatchable(vnode)) {
+      invokeCreateHooks(vnode, insertedVnodeQueue)
+      setScope(vnode)
+    } else {
+      // empty component root.
+      // skip all element-related modules except for ref (#3455)
+      registerRef(vnode)
+      // make sure to invoke the insert hook
+      insertedVnodeQueue.push(vnode)
+    }
+  }
+
+  function reactivateComponent (vnode, insertedVnodeQueue, parentElm, refElm) {
+    let i
+    // hack for #4339: a reactivated component with inner transition
+    // does not trigger because the inner node's created hooks are not called
+    // again. It's not ideal to involve module-specific logic in here but
+    // there doesn't seem to be a better way to do it.
+    let innerNode = vnode
+    while (innerNode.componentInstance) {
+      innerNode = innerNode.componentInstance._vnode
+      if (isDef(i = innerNode.data) && isDef(i = i.transition)) {
+        for (i = 0; i < cbs.activate.length; ++i) {
+          cbs.activate[i](emptyNode, innerNode)
+        }
+        insertedVnodeQueue.push(innerNode)
+        break
+      }
+    }
+    // unlike a newly created component,
+    // a reactivated keep-alive component doesn't insert itself
+    insert(parentElm, vnode.elm, refElm)
+  }
+
+  function insert (parent, elm, ref) {
+    if (isDef(parent)) {
+      if (isDef(ref)) {
+        if (ref.parentNode === parent) {
+          nodeOps.insertBefore(parent, elm, ref)
+        }
+      } else {
+        nodeOps.appendChild(parent, elm)
+      }
+    }
+  }
+
+  function createChildren (vnode, children, insertedVnodeQueue) {
+    if (Array.isArray(children)) {
+      if (process.env.NODE_ENV !== 'production') {
+        checkDuplicateKeys(children)
+      }
+      for (let i = 0; i < children.length; ++i) {
+        createElm(children[i], insertedVnodeQueue, vnode.elm, null, true, children, i)
+      }
+    } else if (isPrimitive(vnode.text)) {
+      nodeOps.appendChild(vnode.elm, nodeOps.createTextNode(String(vnode.text)))
+    }
+  }
+
+  function isPatchable (vnode) {
+    while (vnode.componentInstance) {
+      vnode = vnode.componentInstance._vnode
+    }
+    return isDef(vnode.tag)
+  }
+
+  function invokeCreateHooks (vnode, insertedVnodeQueue) {
+    for (let i = 0; i < cbs.create.length; ++i) {
+      cbs.create[i](emptyNode, vnode)
+    }
+    i = vnode.data.hook // Reuse variable
+    if (isDef(i)) {
+      if (isDef(i.create)) i.create(emptyNode, vnode)
+      if (isDef(i.insert)) insertedVnodeQueue.push(vnode)
+    }
+  }
+
+  // set scope id attribute for scoped CSS.
+  // this is implemented as a special case to avoid the overhead
+  // of going through the normal attribute patching process.
+  function setScope (vnode) {
+    let i
+    if (isDef(i = vnode.fnScopeId)) {
+      nodeOps.setStyleScope(vnode.elm, i)
+    } else {
+      let ancestor = vnode
+      while (ancestor) {
+        if (isDef(i = ancestor.context) && isDef(i = i.$options._scopeId)) {
+          nodeOps.setStyleScope(vnode.elm, i)
+        }
+        ancestor = ancestor.parent
+      }
+    }
+    // for slot content they should also get the scopeId from the host instance.
+    if (isDef(i = activeInstance) &&
+      i !== vnode.context &&
+      i !== vnode.fnContext &&
+      isDef(i = i.$options._scopeId)
+    ) {
+      nodeOps.setStyleScope(vnode.elm, i)
+    }
+  }
+
+  function addVnodes (parentElm, refElm, vnodes, startIdx, endIdx, insertedVnodeQueue) {
+    for (; startIdx <= endIdx; ++startIdx) {
+      createElm(vnodes[startIdx], insertedVnodeQueue, parentElm, refElm, false, vnodes, startIdx)
+    }
+  }
+
+  function invokeDestroyHook (vnode) {
+    let i, j
+    const data = vnode.data
+    if (isDef(data)) {
+      if (isDef(i = data.hook) && isDef(i = i.destroy)) i(vnode)
+      for (i = 0; i < cbs.destroy.length; ++i) cbs.destroy[i](vnode)
+    }
+    if (isDef(i = vnode.children)) {
+      for (j = 0; j < vnode.children.length; ++j) {
+        invokeDestroyHook(vnode.children[j])
+      }
+    }
+  }
+
+  function removeVnodes (parentElm, vnodes, startIdx, endIdx) {
+    for (; startIdx <= endIdx; ++startIdx) {
+      const ch = vnodes[startIdx]
+      if (isDef(ch)) {
+        if (isDef(ch.tag)) {
+          removeAndInvokeRemoveHook(ch)
+          invokeDestroyHook(ch)
+        } else { // Text node
+          removeNode(ch.elm)
+        }
+      }
+    }
+  }
+
+  function removeAndInvokeRemoveHook (vnode, rm) {
+    if (isDef(rm) || isDef(vnode.data)) {
+      let i
+      const listeners = cbs.remove.length + 1
+      if (isDef(rm)) {
+        // we have a recursively passed down rm callback
+        // increase the listeners count
+        rm.listeners += listeners
+      } else {
+        // directly removing
+        rm = createRmCb(vnode.elm, listeners)
+      }
+      // recursively invoke hooks on child component root node
+      if (isDef(i = vnode.componentInstance) && isDef(i = i._vnode) && isDef(i.data)) {
+        removeAndInvokeRemoveHook(i, rm)
+      }
+      for (i = 0; i < cbs.remove.length; ++i) {
+        cbs.remove[i](vnode, rm)
+      }
+      if (isDef(i = vnode.data.hook) && isDef(i = i.remove)) {
+        i(vnode, rm)
+      } else {
+        rm()
+      }
+    } else {
+      removeNode(vnode.elm)
+    }
+  }
+
+  function updateChildren (parentElm, oldCh, newCh, insertedVnodeQueue, removeOnly) {
+    let oldStartIdx = 0
+    let newStartIdx = 0
+    let oldEndIdx = oldCh.length - 1
+    let oldStartVnode = oldCh[0]
+    let oldEndVnode = oldCh[oldEndIdx]
+    let newEndIdx = newCh.length - 1
+    let newStartVnode = newCh[0]
+    let newEndVnode = newCh[newEndIdx]
+    let oldKeyToIdx, idxInOld, vnodeToMove, refElm
+
+    // removeOnly is a special flag used only by <transition-group>
+    // to ensure removed elements stay in correct relative positions
+    // during leaving transitions
+    const canMove = !removeOnly
+
+    if (process.env.NODE_ENV !== 'production') {
+      checkDuplicateKeys(newCh)
+    }
+
+    while (oldStartIdx <= oldEndIdx && newStartIdx <= newEndIdx) {
+      if (isUndef(oldStartVnode)) {
+        oldStartVnode = oldCh[++oldStartIdx] // Vnode has been moved left
+      } else if (isUndef(oldEndVnode)) {
+        oldEndVnode = oldCh[--oldEndIdx]
+      } else if (sameVnode(oldStartVnode, newStartVnode)) {
+        patchVnode(oldStartVnode, newStartVnode, insertedVnodeQueue)
+        oldStartVnode = oldCh[++oldStartIdx]
+        newStartVnode = newCh[++newStartIdx]
+      } else if (sameVnode(oldEndVnode, newEndVnode)) {
+        patchVnode(oldEndVnode, newEndVnode, insertedVnodeQueue)
+        oldEndVnode = oldCh[--oldEndIdx]
+        newEndVnode = newCh[--newEndIdx]
+      } else if (sameVnode(oldStartVnode, newEndVnode)) { // Vnode moved right
+        patchVnode(oldStartVnode, newEndVnode, insertedVnodeQueue)
+        canMove && nodeOps.insertBefore(parentElm, oldStartVnode.elm, nodeOps.nextSibling(oldEndVnode.elm))
+        oldStartVnode = oldCh[++oldStartIdx]
+        newEndVnode = newCh[--newEndIdx]
+      } else if (sameVnode(oldEndVnode, newStartVnode)) { // Vnode moved left
+        patchVnode(oldEndVnode, newStartVnode, insertedVnodeQueue)
+        canMove && nodeOps.insertBefore(parentElm, oldEndVnode.elm, oldStartVnode.elm)
+        oldEndVnode = oldCh[--oldEndIdx]
+        newStartVnode = newCh[++newStartIdx]
+      } else {
+        if (isUndef(oldKeyToIdx)) oldKeyToIdx = createKeyToOldIdx(oldCh, oldStartIdx, oldEndIdx)
+        idxInOld = isDef(newStartVnode.key)
+          ? oldKeyToIdx[newStartVnode.key]
+          : findIdxInOld(newStartVnode, oldCh, oldStartIdx, oldEndIdx)
+        if (isUndef(idxInOld)) { // New element
+          createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm, false, newCh, newStartIdx)
+        } else {
+          vnodeToMove = oldCh[idxInOld]
+          if (sameVnode(vnodeToMove, newStartVnode)) {
+            patchVnode(vnodeToMove, newStartVnode, insertedVnodeQueue)
+            oldCh[idxInOld] = undefined
+            canMove && nodeOps.insertBefore(parentElm, vnodeToMove.elm, oldStartVnode.elm)
+          } else {
+            // same key but different element. treat as new element
+            createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm, false, newCh, newStartIdx)
+          }
+        }
+        newStartVnode = newCh[++newStartIdx]
+      }
+    }
+    if (oldStartIdx > oldEndIdx) {
+      refElm = isUndef(newCh[newEndIdx + 1]) ? null : newCh[newEndIdx + 1].elm
+      addVnodes(parentElm, refElm, newCh, newStartIdx, newEndIdx, insertedVnodeQueue)
+    } else if (newStartIdx > newEndIdx) {
+      removeVnodes(parentElm, oldCh, oldStartIdx, oldEndIdx)
+    }
+  }
+
+  function checkDuplicateKeys (children) {
+    const seenKeys = {}
+    for (let i = 0; i < children.length; i++) {
+      const vnode = children[i]
+      const key = vnode.key
+      if (isDef(key)) {
+        if (seenKeys[key]) {
+          warn(
+            `Duplicate keys detected: '${key}'. This may cause an update error.`,
+            vnode.context
+          )
+        } else {
+          seenKeys[key] = true
+        }
+      }
+    }
+  }
+
+  function findIdxInOld (node, oldCh, start, end) {
+    for (let i = start; i < end; i++) {
+      const c = oldCh[i]
+      if (isDef(c) && sameVnode(node, c)) return i
+    }
+  }
+
+  function patchVnode (oldVnode, vnode, insertedVnodeQueue, removeOnly) {
+    if (oldVnode === vnode) {
+      return
+    }
+
+    const elm = vnode.elm = oldVnode.elm
+
+    if (isTrue(oldVnode.isAsyncPlaceholder)) {
+      if (isDef(vnode.asyncFactory.resolved)) {
+        hydrate(oldVnode.elm, vnode, insertedVnodeQueue)
+      } else {
+        vnode.isAsyncPlaceholder = true
+      }
+      return
+    }
+
+    // reuse element for static trees.
+    // note we only do this if the vnode is cloned -
+    // if the new node is not cloned it means the render functions have been
+    // reset by the hot-reload-api and we need to do a proper re-render.
+    if (isTrue(vnode.isStatic) &&
+      isTrue(oldVnode.isStatic) &&
+      vnode.key === oldVnode.key &&
+      (isTrue(vnode.isCloned) || isTrue(vnode.isOnce))
+    ) {
+      vnode.componentInstance = oldVnode.componentInstance
+      return
+    }
+
+    let i
+    const data = vnode.data
+    if (isDef(data) && isDef(i = data.hook) && isDef(i = i.prepatch)) {
+      i(oldVnode, vnode)
+    }
+
+    const oldCh = oldVnode.children
+    const ch = vnode.children
+    if (isDef(data) && isPatchable(vnode)) {
+      for (i = 0; i < cbs.update.length; ++i) cbs.update[i](oldVnode, vnode)
+      if (isDef(i = data.hook) && isDef(i = i.update)) i(oldVnode, vnode)
+    }
+    if (isUndef(vnode.text)) {
+      if (isDef(oldCh) && isDef(ch)) {
+        if (oldCh !== ch) updateChildren(elm, oldCh, ch, insertedVnodeQueue, removeOnly)
+      } else if (isDef(ch)) {
+        if (isDef(oldVnode.text)) nodeOps.setTextContent(elm, '')
+        addVnodes(elm, null, ch, 0, ch.length - 1, insertedVnodeQueue)
+      } else if (isDef(oldCh)) {
+        removeVnodes(elm, oldCh, 0, oldCh.length - 1)
+      } else if (isDef(oldVnode.text)) {
+        nodeOps.setTextContent(elm, '')
+      }
+    } else if (oldVnode.text !== vnode.text) {
+      nodeOps.setTextContent(elm, vnode.text)
+    }
+    if (isDef(data)) {
+      if (isDef(i = data.hook) && isDef(i = i.postpatch)) i(oldVnode, vnode)
+    }
+  }
+
+  function invokeInsertHook (vnode, queue, initial) {
+    // delay insert hooks for component root nodes, invoke them after the
+    // element is really inserted
+    if (isTrue(initial) && isDef(vnode.parent)) {
+      vnode.parent.data.pendingInsert = queue
+    } else {
+      for (let i = 0; i < queue.length; ++i) {
+        queue[i].data.hook.insert(queue[i])
+      }
+    }
+  }
+
+  let hydrationBailed = false
+  // list of modules that can skip create hook during hydration because they
+  // are already rendered on the client or has no need for initialization
+  // Note: style is excluded because it relies on initial clone for future
+  // deep updates (#7063).
+  const isRenderedModule = makeMap('attrs,class,staticClass,staticStyle,key')
+
+  // Note: this is a browser-only function so we can assume elms are DOM nodes.
+  function hydrate (elm, vnode, insertedVnodeQueue, inVPre) {
+    let i
+    const { tag, data, children } = vnode
+    inVPre = inVPre || (data && data.pre)
+    vnode.elm = elm
+
+    if (isTrue(vnode.isComment) && isDef(vnode.asyncFactory)) {
+      vnode.isAsyncPlaceholder = true
+      return true
+    }
+    // assert node match
+    if (process.env.NODE_ENV !== 'production') {
+      if (!assertNodeMatch(elm, vnode, inVPre)) {
+        return false
+      }
+    }
+    if (isDef(data)) {
+      if (isDef(i = data.hook) && isDef(i = i.init)) i(vnode, true /* hydrating */)
+      if (isDef(i = vnode.componentInstance)) {
+        // child component. it should have hydrated its own tree.
+        initComponent(vnode, insertedVnodeQueue)
+        return true
+      }
+    }
+    if (isDef(tag)) {
+      if (isDef(children)) {
+        // empty element, allow client to pick up and populate children
+        if (!elm.hasChildNodes()) {
+          createChildren(vnode, children, insertedVnodeQueue)
+        } else {
+          // v-html and domProps: innerHTML
+          if (isDef(i = data) && isDef(i = i.domProps) && isDef(i = i.innerHTML)) {
+            if (i !== elm.innerHTML) {
+              /* istanbul ignore if */
+              if (process.env.NODE_ENV !== 'production' &&
+                typeof console !== 'undefined' &&
+                !hydrationBailed
+              ) {
+                hydrationBailed = true
+                console.warn('Parent: ', elm)
+                console.warn('server innerHTML: ', i)
+                console.warn('client innerHTML: ', elm.innerHTML)
+              }
+              return false
+            }
+          } else {
+            // iterate and compare children lists
+            let childrenMatch = true
+            let childNode = elm.firstChild
+            for (let i = 0; i < children.length; i++) {
+              if (!childNode || !hydrate(childNode, children[i], insertedVnodeQueue, inVPre)) {
+                childrenMatch = false
+                break
+              }
+              childNode = childNode.nextSibling
+            }
+            // if childNode is not null, it means the actual childNodes list is
+            // longer than the virtual children list.
+            if (!childrenMatch || childNode) {
+              /* istanbul ignore if */
+              if (process.env.NODE_ENV !== 'production' &&
+                typeof console !== 'undefined' &&
+                !hydrationBailed
+              ) {
+                hydrationBailed = true
+                console.warn('Parent: ', elm)
+                console.warn('Mismatching childNodes vs. VNodes: ', elm.childNodes, children)
+              }
+              return false
+            }
+          }
+        }
+      }
+      if (isDef(data)) {
+        let fullInvoke = false
+        for (const key in data) {
+          if (!isRenderedModule(key)) {
+            fullInvoke = true
+            invokeCreateHooks(vnode, insertedVnodeQueue)
+            break
+          }
+        }
+        if (!fullInvoke && data['class']) {
+          // ensure collecting deps for deep class bindings for future updates
+          traverse(data['class'])
+        }
+      }
+    } else if (elm.data !== vnode.text) {
+      elm.data = vnode.text
+    }
+    return true
+  }
+
+  function assertNodeMatch (node, vnode, inVPre) {
+    if (isDef(vnode.tag)) {
+      return vnode.tag.indexOf('vue-component') === 0 || (
+        !isUnknownElement(vnode, inVPre) &&
+        vnode.tag.toLowerCase() === (node.tagName && node.tagName.toLowerCase())
+      )
+    } else {
+      return node.nodeType === (vnode.isComment ? 8 : 3)
+    }
+  }
+
+  return function patch (oldVnode, vnode, hydrating, removeOnly, parentElm, refElm) {
+    if (isUndef(vnode)) {
+      if (isDef(oldVnode)) invokeDestroyHook(oldVnode)
+      return
+    }
+
+    let isInitialPatch = false
+    const insertedVnodeQueue = []
+
+    if (isUndef(oldVnode)) {
+      // empty mount (likely as component), create new root element
+      isInitialPatch = true
+      createElm(vnode, insertedVnodeQueue, parentElm, refElm)
+    } else {
+      const isRealElement = isDef(oldVnode.nodeType)
+      if (!isRealElement && sameVnode(oldVnode, vnode)) {
+        // patch existing root node
+        patchVnode(oldVnode, vnode, insertedVnodeQueue, removeOnly)
+      } else {
+        if (isRealElement) {
+          // mounting to a real element
+          // check if this is server-rendered content and if we can perform
+          // a successful hydration.
+          if (oldVnode.nodeType === 1 && oldVnode.hasAttribute(SSR_ATTR)) {
+            oldVnode.removeAttribute(SSR_ATTR)
+            hydrating = true
+          }
+          if (isTrue(hydrating)) {
+            if (hydrate(oldVnode, vnode, insertedVnodeQueue)) {
+              invokeInsertHook(vnode, insertedVnodeQueue, true)
+              return oldVnode
+            } else if (process.env.NODE_ENV !== 'production') {
+              warn(
+                'The client-side rendered virtual DOM tree is not matching ' +
+                'server-rendered content. This is likely caused by incorrect ' +
+                'HTML markup, for example nesting block-level elements inside ' +
+                '<p>, or missing <tbody>. Bailing hydration and performing ' +
+                'full client-side render.'
+              )
+            }
+          }
+          // either not server-rendered, or hydration failed.
+          // create an empty node and replace it
+          oldVnode = emptyNodeAt(oldVnode)
+        }
+
+        // replacing existing element
+        const oldElm = oldVnode.elm
+        const parentElm = nodeOps.parentNode(oldElm)
+
+        // create new node
+        createElm(
+          vnode,
+          insertedVnodeQueue,
+          // extremely rare edge case: do not insert if old element is in a
+          // leaving transition. Only happens when combining transition +
+          // keep-alive + HOCs. (#4590)
+          oldElm._leaveCb ? null : parentElm,
+          nodeOps.nextSibling(oldElm)
+        )
+
+        // update parent placeholder node element, recursively
+        if (isDef(vnode.parent)) {
+          let ancestor = vnode.parent
+          const patchable = isPatchable(vnode)
+          while (ancestor) {
+            for (let i = 0; i < cbs.destroy.length; ++i) {
+              cbs.destroy[i](ancestor)
+            }
+            ancestor.elm = vnode.elm
+            if (patchable) {
+              for (let i = 0; i < cbs.create.length; ++i) {
+                cbs.create[i](emptyNode, ancestor)
+              }
+              // #6513
+              // invoke insert hooks that may have been merged by create hooks.
+              // e.g. for directives that uses the "inserted" hook.
+              const insert = ancestor.data.hook.insert
+              if (insert.merged) {
+                // start at index 1 to avoid re-invoking component mounted hook
+                for (let i = 1; i < insert.fns.length; i++) {
+                  insert.fns[i]()
+                }
+              }
+            } else {
+              registerRef(ancestor)
+            }
+            ancestor = ancestor.parent
+          }
+        }
+
+        // destroy old node
+        if (isDef(parentElm)) {
+          removeVnodes(parentElm, [oldVnode], 0, 0)
+        } else if (isDef(oldVnode.tag)) {
+          invokeDestroyHook(oldVnode)
+        }
+      }
+    }
+
+    invokeInsertHook(vnode, insertedVnodeQueue, isInitialPatch)
+    return vnode.elm
+  }
+}