Function renderNode

packages/react-server/src/ReactFizzServer.js:4131–4404

(
  request: Request,
  task: Task,
  node: ReactNodeList,
  childIndex: number,
)

// This is a non-destructive form of rendering a node. If it suspends it spawns
// a new task and restores the context of this task to what it was before.
function renderNode(
  request: Request,
  task: Task,
  node: ReactNodeList,
  childIndex: number,
): void {
  // Snapshot the current context in case something throws to interrupt the
  // process.
  const previousFormatContext = task.formatContext;
  const previousLegacyContext = !disableLegacyContext
    ? task.legacyContext
    : emptyContextObject;
  const previousContext = task.context;
  const previousKeyPath = task.keyPath;
  const previousTreeContext = task.treeContext;
  const previousComponentStack = task.componentStack;
  const previousDebugTask = __DEV__ ? task.debugTask : null;
  let x;
  // Store how much we've pushed at this point so we can reset it in case something
  // suspended partially through writing something.
  const segment = task.blockedSegment;
  if (segment === null) {
    // Replay
    task = ((task: any): ReplayTask); // Refined
    const previousReplaySet: ReplaySet = task.replay;
    try {
      return renderNodeDestructive(request, task, node, childIndex);
    } catch (thrownValue) {
      resetHooksState();

      x =
        thrownValue === SuspenseException
          ? // This is a special type of exception used for Suspense. For historical
            // reasons, the rest of the Suspense implementation expects the thrown
            // value to be a thenable, because before `use` existed that was the
            // (unstable) API for suspending. This implementation detail can change
            // later, once we deprecate the old API in favor of `use`.
            getSuspendedThenable()
          : thrownValue;

      if (request.status === ABORTING) {
        // We are aborting so we can just bubble up to the task by falling through
      } else if (typeof x === 'object' && x !== null) {
        // $FlowFixMe[method-unbinding]
        if (typeof x.then === 'function') {
          const wakeable: Wakeable = (x: any);
          const thenableState =
            thrownValue === SuspenseException
              ? getThenableStateAfterSuspending()
              : null;
          const newTask = spawnNewSuspendedReplayTask(
            request,
            // $FlowFixMe: Refined.
            task,
            thenableState,
          );
          const ping = newTask.ping;
          wakeable.then(ping, ping);