Function updateHostRoot

docs/external/js/react-dom.development.js:17342–17398

(current, workInProgress, renderExpirationTime)

  }

  function updateHostRoot(current, workInProgress, renderExpirationTime) {
    pushHostRootContext(workInProgress);
    var updateQueue = workInProgress.updateQueue;

    if (!(current !== null && updateQueue !== null)) {
      {
        throw Error( "If the root does not have an updateQueue, we should have already bailed out. This error is likely caused by a bug in React. Please file an issue." );
      }
    }

    var nextProps = workInProgress.pendingProps;
    var prevState = workInProgress.memoizedState;
    var prevChildren = prevState !== null ? prevState.element : null;
    cloneUpdateQueue(current, workInProgress);
    processUpdateQueue(workInProgress, nextProps, null, renderExpirationTime);
    var nextState = workInProgress.memoizedState; // Caution: React DevTools currently depends on this property
    // being called "element".

    var nextChildren = nextState.element;

    if (nextChildren === prevChildren) {
      // If the state is the same as before, that's a bailout because we had
      // no work that expires at this time.
      resetHydrationState();
      return bailoutOnAlreadyFinishedWork(current, workInProgress, renderExpirationTime);
    }

    var root = workInProgress.stateNode;

    if (root.hydrate && enterHydrationState(workInProgress)) {
      // If we don't have any current children this might be the first pass.
      // We always try to hydrate. If this isn't a hydration pass there won't
      // be any children to hydrate which is effectively the same thing as
      // not hydrating.
      var child = mountChildFibers(workInProgress, null, nextChildren, renderExpirationTime);
      workInProgress.child = child;
      var node = child;

      while (node) {
        // Mark each child as hydrating. This is a fast path to know whether this
        // tree is part of a hydrating tree. This is used to determine if a child
        // node has fully mounted yet, and for scheduling event replaying.
        // Conceptually this is similar to Placement in that a new subtree is
        // inserted into the React tree here. It just happens to not need DOM
        // mutations because it already exists.
        node.effectTag = node.effectTag & ~Placement | Hydrating;
        node = node.sibling;
      }
    } else {
      // Otherwise reset hydration state in case we aborted and resumed another
      // root.
      reconcileChildren(current, workInProgress, nextChildren, renderExpirationTime);
      resetHydrationState();
    }

    return workInProgress.child;
  }