case REACT_ELEMENT_TYPE: {
          const created = createFiberFromElement(
            newChild,
            returnFiber.mode,
            expirationTime,
          );
          created.ref = coerceRef(null, newChild);
          created.return = returnFiber;
          return created;
        }
        case REACT_PORTAL_TYPE: {
          const created = createFiberFromPortal(
            newChild,
            returnFiber.mode,
            expirationTime,
          );
          created.return = returnFiber;
          return created;
        }
      }
      if (isArray(newChild) || getIteratorFn(newChild)) {
        const created = createFiberFromFragment(
          newChild,
          returnFiber.mode,
          expirationTime,
          null,
        );