Function mountSuspenseFallbackChildren

dash/deps/react-dom@18.3.1.js:20449–20488

(workInProgress, primaryChildren, fallbackChildren, renderLanes)

  }

  function mountSuspenseFallbackChildren(workInProgress, primaryChildren, fallbackChildren, renderLanes) {
    var mode = workInProgress.mode;
    var progressedPrimaryFragment = workInProgress.child;
    var primaryChildProps = {
      mode: 'hidden',
      children: primaryChildren
    };
    var primaryChildFragment;
    var fallbackChildFragment;

    if ((mode & ConcurrentMode) === NoMode && progressedPrimaryFragment !== null) {
      // In legacy mode, we commit the primary tree as if it successfully
      // completed, even though it's in an inconsistent state.
      primaryChildFragment = progressedPrimaryFragment;
      primaryChildFragment.childLanes = NoLanes;
      primaryChildFragment.pendingProps = primaryChildProps;

      if ( workInProgress.mode & ProfileMode) {
        // Reset the durations from the first pass so they aren't included in the
        // final amounts. This seems counterintuitive, since we're intentionally
        // not measuring part of the render phase, but this makes it match what we
        // do in Concurrent Mode.
        primaryChildFragment.actualDuration = 0;
        primaryChildFragment.actualStartTime = -1;
        primaryChildFragment.selfBaseDuration = 0;
        primaryChildFragment.treeBaseDuration = 0;
      }

      fallbackChildFragment = createFiberFromFragment(fallbackChildren, mode, renderLanes, null);
    } else {
      primaryChildFragment = mountWorkInProgressOffscreenFiber(primaryChildProps, mode);
      fallbackChildFragment = createFiberFromFragment(fallbackChildren, mode, renderLanes, null);
    }

    primaryChildFragment.return = workInProgress;
    fallbackChildFragment.return = workInProgress;
    primaryChildFragment.sibling = fallbackChildFragment;
    workInProgress.child = primaryChildFragment;
    return fallbackChildFragment;
  }

  function mountWorkInProgressOffscreenFiber(offscreenProps, mode, renderLanes) {
    // The props argument to `createFiberFromOffscreen` is `any` typed, so we use