unwindWork() — react Function Reference

Source Code

packages/react-reconciler/src/ReactFiberUnwindWork.js lines 66–249

function unwindWork(
  current: Fiber | null,
  workInProgress: Fiber,
  renderLanes: Lanes,
): Fiber | null {
  // Note: This intentionally doesn't check if we're hydrating because comparing
  // to the current tree provider fiber is just as fast and less error-prone.
  // Ideally we would have a special version of the work loop only
  // for hydration.
  popTreeContext(workInProgress);
  switch (workInProgress.tag) {
    case ClassComponent: {
      const Component = workInProgress.type;
      if (isLegacyContextProvider(Component)) {
        popLegacyContext(workInProgress);
      }
      const flags = workInProgress.flags;
      if (flags & ShouldCapture) {
        workInProgress.flags = (flags & ~ShouldCapture) | DidCapture;
        if (
          enableProfilerTimer &&
          (workInProgress.mode & ProfileMode) !== NoMode
        ) {
          transferActualDuration(workInProgress);
        }
        return workInProgress;
      }
      return null;
    }
    case HostRoot: {
      const root: FiberRoot = workInProgress.stateNode;
      const cache: Cache = workInProgress.memoizedState.cache;
      popCacheProvider(workInProgress, cache);

      if (enableTransitionTracing) {
        popRootMarkerInstance(workInProgress);
      }

      popRootTransition(workInProgress, root, renderLanes);
      popHostContainer(workInProgress);
      popTopLevelLegacyContextObject(workInProgress);
      const flags = workInProgress.flags;
      if (
        (flags & ShouldCapture) !== NoFlags &&
        (flags & DidCapture) === NoFlags
      ) {
        // There was an error during render that wasn't captured by a suspense
        // boundary. Do a second pass on the root to unmount the children.
        workInProgress.flags = (flags & ~ShouldCapture) | DidCapture;
        return workInProgress;
      }
      // We unwound to the root without completing it. Exit.
      return null;
    }
    case HostHoistable:
    case HostSingleton:
    case HostComponent: {
      // TODO: popHydrationState
      popHostContext(workInProgress);
      return null;
    }
    case ActivityComponent: {
      const activityState: null | ActivityState = workInProgress.memoizedState;
      if (activityState !== null) {
        popSuspenseHandler(workInProgress);

        if (workInProgress.alternate === null) {
          throw new Error(
            'Threw in newly mounted dehydrated component. This is likely a bug in ' +
              'React. Please file an issue.',
          );
        }

        resetHydrationState();
      }

      const flags = workInProgress.flags;
      if (flags & ShouldCapture) {
        workInProgress.flags = (flags & ~ShouldCapture) | DidCapture;
        // Captured a suspense effect. Re-render the boundary.
        if (