Function reconcileChildrenArray

docs/index.js:6582–6676

(
    returnFiber,
    currentFirstChild,
    newChildren,
    lanes
  )

    return null;
  }
  function reconcileChildrenArray(
    returnFiber,
    currentFirstChild,
    newChildren,
    lanes
  ) {
    for (
      var resultingFirstChild = null,
        previousNewFiber = null,
        oldFiber = currentFirstChild,
        newIdx = (currentFirstChild = 0),
        nextOldFiber = null;
      null !== oldFiber && newIdx < newChildren.length;
      newIdx++
    ) {
      oldFiber.index > newIdx
        ? ((nextOldFiber = oldFiber), (oldFiber = null))
        : (nextOldFiber = oldFiber.sibling);
      var newFiber = updateSlot(
        returnFiber,
        oldFiber,
        newChildren[newIdx],
        lanes
      );
      if (null === newFiber) {
        null === oldFiber && (oldFiber = nextOldFiber);
        break;
      }
      shouldTrackSideEffects &&
        oldFiber &&
        null === newFiber.alternate &&
        deleteChild(returnFiber, oldFiber);
      currentFirstChild = placeChild(newFiber, currentFirstChild, newIdx);
      null === previousNewFiber
        ? (resultingFirstChild = newFiber)
        : (previousNewFiber.sibling = newFiber);
      previousNewFiber = newFiber;
      oldFiber = nextOldFiber;
    }
    if (newIdx === newChildren.length)
      return (
        deleteRemainingChildren(returnFiber, oldFiber),
        isHydrating && pushTreeFork(returnFiber, newIdx),
        resultingFirstChild
      );
    if (null === oldFiber) {
      for (; newIdx < newChildren.length; newIdx++)
        (oldFiber = createChild(returnFiber, newChildren[newIdx], lanes)),
          null !== oldFiber &&
            ((currentFirstChild = placeChild(
              oldFiber,
              currentFirstChild,
              newIdx
            )),
            null === previousNewFiber
              ? (resultingFirstChild = oldFiber)
              : (previousNewFiber.sibling = oldFiber),
            (previousNewFiber = oldFiber));