Function reconcileSingleElement

code/redux/public/app.js:9804–9841

(returnFiber, currentFirstChild, element, expirationTime)

  }

  function reconcileSingleElement(returnFiber, currentFirstChild, element, expirationTime) {
    var key = element.key;
    var child = currentFirstChild;
    while (child !== null) {
      // TODO: If key === null and child.key === null, then this only applies to
      // the first item in the list.
      if (child.key === key) {
        if (child.tag === Fragment ? element.type === REACT_FRAGMENT_TYPE : child.type === element.type) {
          deleteRemainingChildren(returnFiber, child.sibling);
          var existing = useFiber(child, element.type === REACT_FRAGMENT_TYPE ? element.props.children : element.props, expirationTime);
          existing.ref = coerceRef(returnFiber, child, element);
          existing['return'] = returnFiber;
          {
            existing._debugSource = element._source;
            existing._debugOwner = element._owner;
          }
          return existing;
        } else {
          deleteRemainingChildren(returnFiber, child);
          break;
        }
      } else {
        deleteChild(returnFiber, child);
      }
      child = child.sibling;
    }

    if (element.type === REACT_FRAGMENT_TYPE) {
      var created = createFiberFromFragment(element.props.children, returnFiber.mode, expirationTime, element.key);
      created['return'] = returnFiber;
      return created;
    } else {
      var _created4 = createFiberFromElement(element, returnFiber.mode, expirationTime);
      _created4.ref = coerceRef(returnFiber, currentFirstChild, element);
      _created4['return'] = returnFiber;
      return _created4;
    }
  }

  function reconcileSinglePortal(returnFiber, currentFirstChild, portal, expirationTime) {
    var key = portal.key;