Function serializeIONode

packages/react-server/src/ReactFlightServer.js:4435–4499

(
  request: Request,
  ioNode: IONode | PromiseNode | UnresolvedPromiseNode,
  promiseRef: null | WeakRef<Promise<mixed>>,
)

}

function serializeIONode(
  request: Request,
  ioNode: IONode | PromiseNode | UnresolvedPromiseNode,
  promiseRef: null | WeakRef<Promise<mixed>>,
): string {
  const existingRef = request.writtenDebugObjects.get(ioNode);
  if (existingRef !== undefined) {
    // Already written
    return existingRef;
  }

  let stack = null;
  let name = '';
  if (ioNode.stack !== null) {
    // The stack can contain some leading internal frames for the construction of the promise that we skip.
    const fullStack = stripLeadingPromiseCreationFrames(ioNode.stack);
    stack = filterStackTrace(request, fullStack);
    name = findCalledFunctionNameFromStackTrace(request, fullStack);
    // The name can include the object that this was called on but sometimes that's
    // just unnecessary context.
    if (name.startsWith('Window.')) {
      name = name.slice(7);
    } else if (name.startsWith('<anonymous>.')) {
      name = name.slice(7);
    }
  }
  const owner = ioNode.owner;
  // Ensure the owner is already outlined.
  if (owner != null) {
    outlineComponentInfo(request, owner);
  }

  let value: void | Promise<mixed> = undefined;
  if (promiseRef !== null) {
    value = promiseRef.deref();
  }

  // We log the environment at the time when we serialize the I/O node.
  // The environment name may have changed from when the I/O was actually started.
  const env = (0, request.environmentName)();

  const endTime =
    ioNode.tag === UNRESOLVED_PROMISE_NODE
      ? // Mark the end time as now. It's arbitrary since it's not resolved but this
        // marks when we called abort and therefore stopped trying.
        request.abortTime
      : ioNode.end;

  request.pendingDebugChunks++;
  const id = request.nextChunkId++;
  emitIOInfoChunk(
    request,
    id,
    name,
    ioNode.start,
    endTime,
    value,
    env,