Function renderDebugModel

packages/react-server/src/ReactFlightServer.js:4582–5057

(
  request: Request,
  counter: {objectLimit: number},
  parent:
    | {+[propertyName: string | number]: ReactClientValue}
    | $ReadOnlyArray<ReactClientValue>,
  parentPropertyName: string,
  value: ReactClientValue,
)

// This is a forked version of renderModel which should never error, never suspend and is limited
// in the depth it can encode.
function renderDebugModel(
  request: Request,
  counter: {objectLimit: number},
  parent:
    | {+[propertyName: string | number]: ReactClientValue}
    | $ReadOnlyArray<ReactClientValue>,
  parentPropertyName: string,
  value: ReactClientValue,
): ReactJSONValue {
  if (value === null) {
    return null;
  }

  // Special Symbol, that's very common.
  if (value === REACT_ELEMENT_TYPE) {
    return '$';
  }

  if (typeof value === 'object') {
    if (isClientReference(value)) {
      // We actually have this value on the client so we could import it.
      // This might be confusing though because on the Server it won't actually
      // be this value, so if you're debugging client references maybe you'd be
      // better with a place holder.
      return serializeDebugClientReference(
        request,
        parent,
        parentPropertyName,
        (value: any),
      );
    }
    if (value.$$typeof === CONSTRUCTOR_MARKER) {
      const constructor: Function = (value: any).constructor;
      let ref = request.writtenDebugObjects.get(constructor);
      if (ref === undefined) {
        const id = outlineDebugModel(request, counter, constructor);
        ref = serializeByValueID(id);
      }
      return '$P' + ref.slice(1);
    }

    if (request.temporaryReferences !== undefined) {
      const tempRef = resolveTemporaryReference(
        request.temporaryReferences,
        value,
      );
      if (tempRef !== undefined) {
        return serializeTemporaryReference(request, tempRef);
      }
    }

    const writtenDebugObjects = request.writtenDebugObjects;
    const existingDebugReference = writtenDebugObjects.get(value);
    if (existingDebugReference !== undefined) {
      if (debugModelRoot === value) {
        // This is the ID we're currently emitting so we need to write it
        // once but if we discover it again, we refer to it by id.
        debugModelRoot = null;