Function updateContainerImpl

packages/react-reconciler/src/ReactFiberReconciler.js:396–461

(
  rootFiber: Fiber,
  lane: Lane,
  element: ReactNodeList,
  container: OpaqueRoot,
  parentComponent: ?component(...props: any),
  callback: ?Function,
)

}

function updateContainerImpl(
  rootFiber: Fiber,
  lane: Lane,
  element: ReactNodeList,
  container: OpaqueRoot,
  parentComponent: ?component(...props: any),
  callback: ?Function,
): void {
  if (__DEV__) {
    onScheduleRoot(container, element);
  }

  if (enableSchedulingProfiler) {
    markRenderScheduled(lane);
  }

  const context = getContextForSubtree(parentComponent);
  if (container.context === null) {
    container.context = context;
  } else {
    container.pendingContext = context;
  }

  if (__DEV__) {
    if (
      ReactCurrentFiberIsRendering &&
      ReactCurrentFiberCurrent !== null &&
      !didWarnAboutNestedUpdates
    ) {
      didWarnAboutNestedUpdates = true;
      console.error(
        'Render methods should be a pure function of props and state; ' +
          'triggering nested component updates from render is not allowed. ' +
          'If necessary, trigger nested updates in componentDidUpdate.\n\n' +
          'Check the render method of %s.',
        getComponentNameFromFiber(ReactCurrentFiberCurrent) || 'Unknown',
      );
    }
  }

  const update = createUpdate(lane);
  // Caution: React DevTools currently depends on this property
  // being called "element".
  update.payload = {element};

  callback = callback === undefined ? null : callback;
  if (callback !== null) {
    if (__DEV__) {
      if (typeof callback !== 'function') {
        console.error(
          'Expected the last optional `callback` argument to be a ' +
            'function. Instead received: %s.',
          callback,
        );
      }
    }
    update.callback = callback;
  }