text: /**
   * Copyright (c) Facebook, Inc. and its affiliates.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   *
   * @flow
   */
  
  import type {
    Instance,
    TextInstance,
    SuspenseInstance,
    Container,
    ChildSet,
    UpdatePayload,
  } from './ReactFiberHostConfig';
  import type {Fiber} from './ReactInternalTypes';
  import type {FiberRoot} from './ReactInternalTypes';
  import type {Lanes} from './ReactFiberLane';
  import type {SuspenseState} from './ReactFiberSuspenseComponent.new';
  import type {UpdateQueue} from './ReactUpdateQueue.new';
  import type {FunctionComponentUpdateQueue} from './ReactFiberHooks.new';
  import type {Wakeable} from 'shared/ReactTypes';
  import type {ReactPriorityLevel} from './ReactInternalTypes';
  import type {OffscreenState} from './ReactFiberOffscreenComponent';
  
  import {unstable_wrap as Schedule_tracing_wrap} from 'scheduler/tracing';
  import {
    enableSchedulerTracing,
    enableProfilerTimer,
    enableProfilerCommitHooks,
    enableSuspenseServerRenderer,
    enableDeprecatedFlareAPI,
    enableFundamentalAPI,
    enableSuspenseCallback,
    enableScopeAPI,
    enableCreateEventHandleAPI,
  } from 'shared/ReactFeatureFlags';
  import {
    FunctionComponent,
    ForwardRef,
    ClassComponent,
    HostRoot,
    HostComponent,
    HostText,
    HostPortal,
    Profiler,
    SuspenseComponent,
    DehydratedFragment,
    IncompleteClassComponent,
    MemoComponent,
    SimpleMemoComponent,
    SuspenseListComponent,
    FundamentalComponent,
    ScopeComponent,
    Block,
    OffscreenComponent,
    LegacyHiddenComponent,
  } from './ReactWorkTags';
  import {
    invokeGuardedCallback,
    hasCaughtError,
    clearCaughtError,
  } from 'shared/ReactErrorUtils';
  import {
    NoEffect,
    ContentReset,
    Placement,
    Snapshot,
    Update,
  } from './ReactSideEffectTags';
  import getComponentName from 'shared/getComponentName';
  import invariant from 'shared/invariant';
  
  import {onCommitUnmount} from './ReactFiberDevToolsHook.new';
  import {resolveDefaultProps} from './ReactFiberLazyComponent.new';
  import {
    getCommitTime,
    recordLayoutEffectDuration,
    startLayoutEffectTimer,
  } from './ReactProfilerTimer.new';
  import {ProfileMode} from './ReactTypeOfMode';
  import {commitUpdateQueue} from './ReactUpdateQueue.new';
  import {
    getPublicInstance,
    supportsMutation,
    supportsPersistence,
    supportsHydration,
    commitMount,
    commitUpdate,
    resetTextContent,
    commitTextUpdate,
    appendChild,
    appendChildToContainer,
    insertBefore,
    insertInContainerBefore,
    removeChild,
    removeChildFromContainer,
    clearSuspenseBoundary,
    clearSuspenseBoundaryFromContainer,
    replaceContainerChildren,
    createContainerChildSet,
    hideInstance,
    hideTextInstance,
    unhideInstance,
    unhideTextInstance,
    unmountFundamentalComponent,
    updateFundamentalComponent,
    commitHydratedContainer,
    commitHydratedSuspenseInstance,
    removeInstanceEventHandles,
    clearContainer,
    prepareScopeUpdate,
    removeScopeEventHandles,
  } from './ReactFiberHostConfig';
  import {
    captureCommitPhaseError,
    resolveRetryWakeable,
    markCommitTimeOfFallback,
    enqueuePendingPassiveHookEffectMount,
    enqueuePendingPassiveHookEffectUnmount,
    enqueuePendingPassiveProfilerEffect,
  } from './ReactFiberWorkLoop.new';
  import {
    NoEffect as NoHookEffect,
    HasEffect as HookHasEffect,
    Layout as HookLayout,
    Passive as HookPassive,
  } from './ReactHookEffectTags';
  import {didWarnAboutReassigningProps} from './ReactFiberBeginWork.new';
  import {
    updateDeprecatedEventListeners,
    unmountDeprecatedResponderListeners,
  } from './ReactFiberDeprecatedEvents.new';
  
  let didWarnAboutUndefinedSnapshotBeforeUpdate: Set<mixed> | null = null;
  if (__DEV__) {
    didWarnAboutUndefinedSnapshotBeforeUpdate = new Set();
  }
  
  const PossiblyWeakSet = typeof WeakSet === 'function' ? WeakSet : Set;
  
  const callComponentWillUnmountWithTimer = function(current, instance) {
    instance.props = current.memoizedProps;
    instance.state = current.memoizedState;
    if (
      enableProfilerTimer &&
      enableProfilerCommitHooks &&
      current.mode & ProfileMode
    ) {
      try {
        startLayoutEffectTimer();
        instance.componentWillUnmount();
      } finally {
        recordLayoutEffectDuration(current);
      }
    } else {
      instance.componentWillUnmount();
    }
  };
  
  // Capture errors so they don't interrupt unmounting.
  function safelyCallComponentWillUnmount(current, instance) {
    if (__DEV__) {
      invokeGuardedCallback(
        null,
        callComponentWillUnmountWithTimer,
        null,
        current,
        instance,
      );
      if (hasCaughtError()) {
        const unmountError = clearCaughtError();
        captureCommitPhaseError(current, unmountError);
      }
    } else {
      try {
        callComponentWillUnmountWithTimer(current, instance);
      } catch (unmountError) {
        captureCommitPhaseError(current, unmountError);
      }
    }
  }
  
  function safelyDetachRef(current: Fiber) {
    const ref = current.ref;
    if (ref !== null) {
      if (typeof ref === 'function') {
        if (__DEV__) {
          invokeGuardedCallback(null, ref, null, null);
          if (hasCaughtError()) {
            const refError = clearCaughtError();
            captureCommitPhaseError(current, refError);
          }
        } else {
          try {
            ref(null);
          } catch (refError) {
            captureCommitPhaseError(current, refError);
          }
        }
      } else {
        ref.current = null;
      }
    }
  }
  
  function safelyCallDestroy(current, destroy) {
    if (__DEV__) {
      invokeGuardedCallback(null, destroy, null);
      if (hasCaughtError()) {
        const error = clearCaughtError();
        captureCommitPhaseError(current, error);
      }
    } else {
      try {
        destroy();
      } catch (error) {
        captureCommitPhaseError(current, error);
      }
    }
  }
  
  function commitBeforeMutationLifeCycles(
    current: Fiber | null,
    finishedWork: Fiber,
  ): void {
    switch (finishedWork.tag) {
      case FunctionComponent:
      case ForwardRef:
      case SimpleMemoComponent:
      case Block: {
        return;
      }
      case ClassComponent: {
        if (finishedWork.effectTag & Snapshot) {
          if (current !== null) {
            const prevProps = current.memoizedProps;
            const prevState = current.memoizedState;
            const instance = finishedWork.stateNode;
            // We could update instance props and state here,
            // but instead we rely on them being set during last render.
            // TODO: revisit this when we implement resuming.
            if (__DEV__) {
              if (
                finishedWork.type === finishedWork.elementType &&
                !didWarnAboutReassigningProps
              ) {
                if (instance.props !== finishedWork.memoizedProps) {
                  console.error(
                    'Expected %s props to match memoized props before ' +
                      'getSnapshotBeforeUpdate. ' +
                      'This might either be because of a bug in React, or because ' +
                      'a component reassigns its own `this.props`. ' +
                      'Please file an issue.',
                    getComponentName(finishedWork.type) || 'instance',
                  );
                }
                if (instance.state !== finishedWork.memoizedState) {
                  console.error(
                    'Expected %s state to match memoized state before ' +
                      'getSnapshotBeforeUpdate. ' +
                      'This might either be because of a bug in React, or because ' +
                      'a component reassigns its own `this.state`. ' +
                      'Please file an issue.',
                    getComponentName(finishedWork.type) || 'instance',
                  );
                }
              }
            }
            const snapshot = instance.getSnapshotBeforeUpdate(
              finishedWork.elementType === finishedWork.type
                ? prevProps
                : resolveDefaultProps(finishedWork.type, prevProps),
              prevState,
            );
            if (__DEV__) {
              const didWarnSet = ((didWarnAboutUndefinedSnapshotBeforeUpdate: any): Set<mixed>);
              if (snapshot === undefined && !didWarnSet.has(finishedWork.type)) {
                didWarnSet.add(finishedWork.type);
                console.error(
                  '%s.getSnapshotBeforeUpdate(): A snapshot value (or null) ' +
                    'must be returned. You have returned undefined.',
                  getComponentName(finishedWork.type),
                );
              }
            }
            instance.__reactInternalSnapshotBeforeUpdate = snapshot;
          }
        }
        return;
      }
      case HostRoot: {
        if (supportsMutation) {
          if (finishedWork.effectTag & Snapshot) {
            const root = finishedWork.stateNode;
            clearContainer(root.containerInfo);
          }
        }
        return;
      }
      case HostComponent:
      case HostText:
      case HostPortal:
      case IncompleteClassComponent:
        // Nothing to do for these component types
        return;
    }
    invariant(
      false,
      'This unit of work tag should not have side-effects. This error is ' +
        'likely caused by a bug in React. Please file an issue.',
    );
  }
  
  function commitHookEffectListUnmount(tag: number, finishedWork: Fiber) {
    const updateQueue: FunctionComponentUpdateQueue | null = (finishedWork.updateQueue: any);
    const lastEffect = updateQueue !== null ? updateQueue.lastEffect : null;
    if (lastEffect !== null) {
      const firstEffect = lastEffect.next;
      let effect = firstEffect;
      do {
        if ((effect.tag & tag) === tag) {
          // Unmount
          const destroy = effect.destroy;
          effect.destroy = undefined;
          if (destroy !== undefined) {
            destroy();
          }
        }
        effect = effect.next;
      } while (effect !== firstEffect);
    }
  }
  
  function commitHookEffectListMount(tag: number, finishedWork: Fiber) {
    const updateQueue: FunctionComponentUpdateQueue | null = (finishedWork.updateQueue: any);
    const lastEffect = updateQueue !== null ? updateQueue.lastEffect : null;
    if (lastEffect !== null) {
      const firstEffect = lastEffect.next;
      let effect = firstEffect;
      do {
        if ((effect.tag & tag) === tag) {
          // Mount
          const create = effect.create;
          effect.destroy = create();
  
          if (__DEV__) {
            const destroy = effect.destroy;
            if (destroy !== undefined && typeof destroy !== 'function') {
              let addendum;
              if (destroy === null) {
                addendum =
                  ' You returned null. If your effect does not require clean ' +
                  'up, return undefined (or nothing).';
              } else if (typeof destroy.then === 'function') {
                addendum =
                  '\n\nIt looks like you wrote useEffect(async () => ...) or returned a Promise. ' +
                  'Instead, write the async function inside your effect ' +
                  'and call it immediately:\n\n' +
                  'useEffect(() => {\n' +
                  '  async function fetchData() {\n' +
                  '    // You can await here\n' +
                  '    const response = await MyAPI.getData(someId);\n' +
                  '    // ...\n' +
                  '  }\n' +
                  '  fetchData();\n' +
                  `}, [someId]); // Or [] if effect doesn't need props or state\n\n` +
                  'Learn more about data fetching with Hooks: https://fb.me/react-hooks-data-fetching';
              } else {
                addendum = ' You returned: ' + destroy;
              }
              console.error(
                'An effect function must not return anything besides a function, ' +
                  'which is used for clean-up.%s',
                addendum,
              );
            }
          }
        }
        effect = effect.next;
      } while (effect !== firstEffect);
    }
  }
  
  function schedulePassiveEffects(finishedWork: Fiber) {
    const updateQueue: FunctionComponentUpdateQueue | null = (finishedWork.updateQueue: any);
    const lastEffect = updateQueue !== null ? updateQueue.lastEffect : null;
    if (lastEffect !== null) {
      const firstEffect = lastEffect.next;
      let effect = firstEffect;
      do {
        const {next, tag} = effect;
        if (
          (tag & HookPassive) !== NoHookEffect &&
          (tag & HookHasEffect) !== NoHookEffect
        ) {
          enqueuePendingPassiveHookEffectUnmount(finishedWork, effect);
          enqueuePendingPassiveHookEffectMount(finishedWork, effect);
        }
        effect = next;
      } while (effect !== firstEffect);
    }
  }
  
  export function commitPassiveEffectDurations(
    finishedRoot: FiberRoot,
    finishedWork: Fiber,
  ): void {
    if (enableProfilerTimer && enableProfilerCommitHooks) {
      // Only Profilers with work in their subtree will have an Update effect scheduled.
      if ((finishedWork.effectTag & Update) !== NoEffect) {
        switch (finishedWork.tag) {
          case Profiler: {
            const {passiveEffectDuration} = finishedWork.stateNode;
            const {id, onPostCommit} = finishedWork.memoizedProps;
  
            // This value will still reflect the previous commit phase.
            // It does not get reset until the start of the next commit phase.
            const commitTime = getCommitTime();
  
            if (typeof onPostCommit === 'function') {
              if (enableSchedulerTracing) {
                onPostCommit(
                  id,
                  finishedWork.alternate === null ? 'mount' : 'update',
                  passiveEffectDuration,
                  commitTime,
                  finishedRoot.memoizedInteractions,
                );
              } else {
                onPostCommit(
                  id,
                  finishedWork.alternate === null ? 'mount' : 'update',
                  passiveEffectDuration,
                  commitTime,
                );
              }
            }
  
            // Bubble times to the next nearest ancestor Profiler.
            // After we process that Profiler, we'll bubble further up.
            let parentFiber = finishedWork.return;
            while (parentFiber !== null) {
              if (parentFiber.tag === Profiler) {
                const parentStateNode = parentFiber.stateNode;
                parentStateNode.passiveEffectDuration += passiveEffectDuration;
                break;
              }
              parentFiber = parentFiber.return;
            }
            break;
          }
          default:
            break;
        }
      }
    }
  }
  
  function commitLifeCycles(
    finishedRoot: FiberRoot,
    current: Fiber | null,
    finishedWork: Fiber,
    committedLanes: Lanes,
  ): void {
    switch (finishedWork.tag) {
      case FunctionComponent:
      case ForwardRef:
      case SimpleMemoComponent:
      case Block: {
        // At this point layout effects have already been destroyed (during mutation phase).
        // This is done to prevent sibling component effects from interfering with each other,
        // e.g. a destroy function in one component should never override a ref set
        // by a create function in another component during the same commit.
        if (
          enableProfilerTimer &&
          enableProfilerCommitHooks &&
          finishedWork.mode & ProfileMode
        ) {
          try {
            startLayoutEffectTimer();
            commitHookEffectListMount(HookLayout | HookHasEffect, finishedWork);
          } finally {
            recordLayoutEffectDuration(finishedWork);
          }
        } else {
          commitHookEffectListMount(HookLayout | HookHasEffect, finishedWork);
        }
  
        schedulePassiveEffects(finishedWork);
        return;
      }
      case ClassComponent: {
        const instance = finishedWork.stateNode;
        if (finishedWork.effectTag & Update) {
          if (current === null) {
            // We could update instance props and state here,
            // but instead we rely on them being set during last render.
            // TODO: revisit this when we implement resuming.
            if (__DEV__) {
              if (
                finishedWork.type === finishedWork.elementType &&
                !didWarnAboutReassigningProps
              ) {
                if (instance.props !== finishedWork.memoizedProps) {
                  console.error(
                    'Expected %s props to match memoized props before ' +
                      'componentDidMount. ' +
                      'This might either be because of a bug in React, or because ' +
                      'a component reassigns its own `this.props`. ' +
                      'Please file an issue.',
                    getComponentName(finishedWork.type) || 'instance',
                  );
                }
                if (instance.state !== finishedWork.memoizedState) {
                  console.error(
                    'Expected %s state to match memoized state before ' +
                      'componentDidMount. ' +
                      'This might either be because of a bug in React, or because ' +
                      'a component reassigns its own `this.state`. ' +
                      'Please file an issue.',
                    getComponentName(finishedWork.type) || 'instance',
                  );
                }
              }
            }
            if (
              enableProfilerTimer &&
              enableProfilerCommitHooks &&
              finishedWork.mode & ProfileMode
            ) {
              try {
                startLayoutEffectTimer();
                instance.componentDidMount();
              } finally {
                recordLayoutEffectDuration(finishedWork);
              }
            } else {
              instance.componentDidMount();
            }
          } else {
            const prevProps =
              finishedWork.elementType === finishedWork.type
                ? current.memoizedProps
                : resolveDefaultProps(finishedWork.type, current.memoizedProps);
            const prevState = current.memoizedState;
            // We could update instance props and state here,
            // but instead we rely on them being set during last render.
            // TODO: revisit this when we implement resuming.
            if (__DEV__) {
              if (
                finishedWork.type === finishedWork.elementType &&
                !didWarnAboutReassigningProps
              ) {
                if (instance.props !== finishedWork.memoizedProps) {
                  console.error(
                    'Expected %s props to match memoized props before ' +
                      'componentDidUpdate. ' +
                      'This might either be because of a bug in React, or because ' +
                      'a component reassigns its own `this.props`. ' +
                      'Please file an issue.',
                    getComponentName(finishedWork.type) || 'instance',
                  );
                }
                if (instance.state !== finishedWork.memoizedState) {
                  console.error(
                    'Expected %s state to match memoized state before ' +
                      'componentDidUpdate. ' +
                      'This might either be because of a bug in React, or because ' +
                      'a component reassigns its own `this.state`. ' +
                      'Please file an issue.',
                    getComponentName(finishedWork.type) || 'instance',
                  );
                }
              }
            }
            if (
              enableProfilerTimer &&
              enableProfilerCommitHooks &&
              finishedWork.mode & ProfileMode
            ) {
              try {
                startLayoutEffectTimer();
                instance.componentDidUpdate(
                  prevProps,
                  prevState,
                  instance.__reactInternalSnapshotBeforeUpdate,
                );
              } finally {
                recordLayoutEffectDuration(finishedWork);
              }
            } else {
              instance.componentDidUpdate(
                prevProps,
                prevState,
                instance.__reactInternalSnapshotBeforeUpdate,
              );
            }
          }
        }
  
        // TODO: I think this is now always non-null by the time it reaches the
        // commit phase. Consider removing the type check.
        const updateQueue: UpdateQueue<
          *,
        > | null = (finishedWork.updateQueue: any);
        if (updateQueue !== null) {
          if (__DEV__) {
            if (
              finishedWork.type === finishedWork.elementType &&
              !didWarnAboutReassigningProps
            ) {
              if (instance.props !== finishedWork.memoizedProps) {
                console.error(
                  'Expected %s props to match memoized props before ' +
                    'processing the update queue. ' +
                    'This might either be because of a bug in React, or because ' +
                    'a component reassigns its own `this.props`. ' +
                    'Please file an issue.',
                  getComponentName(finishedWork.type) || 'instance',
                );
              }
              if (instance.state !== finishedWork.memoizedState) {
                console.error(
                  'Expected %s state to match memoized state before ' +
                    'processing the update queue. ' +
                    'This might either be because of a bug in React, or because ' +
                    'a component reassigns its own `this.state`. ' +
                    'Please file an issue.',
                  getComponentName(finishedWork.type) || 'instance',
                );
              }
            }
          }
          // We could update instance props and state here,
          // but instead we rely on them being set during last render.
          // TODO: revisit this when we implement resuming.
          commitUpdateQueue(finishedWork, updateQueue, instance);
        }
        return;
      }
      case HostRoot: {
        // TODO: I think this is now always non-null by the time it reaches the
        // commit phase. Consider removing the type check.
        const updateQueue: UpdateQueue<
          *,
        > | null = (finishedWork.updateQueue: any);
        if (updateQueue !== null) {
          let instance = null;
          if (finishedWork.child !== null) {
            switch (finishedWork.child.tag) {
              case HostComponent:
                instance = getPublicInstance(finishedWork.child.stateNode);
                break;
              case ClassComponent:
                instance = finishedWork.child.stateNode;
                break;
            }
          }
          commitUpdateQueue(finishedWork, updateQueue, instance);
        }
        return;
      }
      case HostComponent: {
        const instance: Instance = finishedWork.stateNode;
  
        // Renderers may schedule work to be done after host components are mounted
        // (eg DOM renderer may schedule auto-focus for inputs and form controls).
        // These effects should only be committed when components are first mounted,
        // aka when there is no current/alternate.
        if (current === null && finishedWork.effectTag & Update) {
          const type = finishedWork.type;
          const props = finishedWork.memoizedProps;
          commitMount(instance, type, props, finishedWork);
        }
  
        return;
      }
      case HostText: {
        // We have no life-cycles associated with text.
        return;
      }
      case HostPortal: {
        // We have no life-cycles associated with portals.
        return;
      }
      case Profiler: {
        if (enableProfilerTimer) {
          const {onCommit, onRender} = finishedWork.memoizedProps;
          const {effectDuration} = finishedWork.stateNode;
  
          const commitTime = getCommitTime();
  
          if (typeof onRender === 'function') {
            if (enableSchedulerTracing) {
              onRender(
                finishedWork.memoizedProps.id,
                current === null ? 'mount' : 'update',
                finishedWork.actualDuration,
                finishedWork.treeBaseDuration,
                finishedWork.actualStartTime,
                commitTime,
                finishedRoot.memoizedInteractions,
              );
            } else {
              onRender(
                finishedWork.memoizedProps.id,
                current === null ? 'mount' : 'update',
                finishedWork.actualDuration,
                finishedWork.treeBaseDuration,
                finishedWork.actualStartTime,
                commitTime,
              );
            }
          }
  
          if (enableProfilerCommitHooks) {
            if (typeof onCommit === 'function') {
              if (enableSchedulerTracing) {
                onCommit(
                  finishedWork.memoizedProps.id,
                  current === null ? 'mount' : 'update',
                  effectDuration,
                  commitTime,
                  finishedRoot.memoizedInteractions,
                );
              } else {
                onCommit(
                  finishedWork.memoizedProps.id,
                  current === null ? 'mount' : 'update',
                  effectDuration,
                  commitTime,
                );
              }
            }
  
            // Schedule a passive effect for this Profiler to call onPostCommit hooks.
            // This effect should be scheduled even if there is no onPostCommit callback for this Profiler,
            // because the effect is also where times bubble to parent Profilers.
            enqueuePendingPassiveProfilerEffect(finishedWork);
  
            // Propagate layout effect durations to the next nearest Profiler ancestor.
            // Do not reset these values until the next render so DevTools has a chance to read them first.
            let parentFiber = finishedWork.return;
            while (parentFiber !== null) {
              if (parentFiber.tag === Profiler) {
                const parentStateNode = parentFiber.stateNode;
                parentStateNode.effectDuration += effectDuration;
                break;
              }
              parentFiber = parentFiber.return;
            }
          }
        }
        return;
      }
      case SuspenseComponent: {
        commitSuspenseHydrationCallbacks(finishedRoot, finishedWork);
        return;
      }
      case SuspenseListComponent:
      case IncompleteClassComponent:
      case FundamentalComponent:
      case ScopeComponent:
      case OffscreenComponent:
      case LegacyHiddenComponent:
        return;
    }
    invariant(
      false,
      'This unit of work tag should not have side-effects. This error is ' +
        'likely caused by a bug in React. Please file an issue.',
    );
  }
  
  function hideOrUnhideAllChildren(finishedWork, isHidden) {
    if (supportsMutation) {
      // We only have the top Fiber that was inserted but we need to recurse down its
      // children to find all the terminal nodes.
      let node: Fiber = finishedWork;
      while (true) {
        if (node.tag === HostComponent) {
          const instance = node.stateNode;
          if (isHidden) {
            hideInstance(instance);
          } else {
            unhideInstance(node.stateNode, node.memoizedProps);
          }
        } else if (node.tag === HostText) {
          const instance = node.stateNode;
          if (isHidden) {
            hideTextInstance(instance);
          } else {
            unhideTextInstance(instance, node.memoizedProps);
          }
        } else if (
          (node.tag === OffscreenComponent ||
            node.tag === LegacyHiddenComponent) &&
          (node.memoizedState: OffscreenState) !== null &&
          node !== finishedWork
        ) {
          // Found a nested Offscreen component that is hidden. Don't search
          // any deeper. This tree should remain hidden.
        } else if (node.child !== null) {
          node.child.return = node;
          node = node.child;
          continue;
        }
        if (node === finishedWork) {
          return;
        }
        while (node.sibling === null) {
          if (node.return === null || node.return === finishedWork) {
            return;
          }
          node = node.return;
        }
        node.sibling.return = node.return;
        node = node.sibling;
      }
    }
  }
  
  function commitAttachRef(finishedWork: Fiber) {
    const ref = finishedWork.ref;
    if (ref !== null) {
      const instance = finishedWork.stateNode;
      let instanceToUse;
      switch (finishedWork.tag) {
        case HostComponent:
          instanceToUse = getPublicInstance(instance);
          break;
        default:
          instanceToUse = instance;
      }
      // Moved outside to ensure DCE works with this flag
      if (enableScopeAPI && finishedWork.tag === ScopeComponent) {
        instanceToUse = instance;
      }
      if (typeof ref === 'function') {
        ref(instanceToUse);
      } else {
        if (__DEV__) {
          if (!ref.hasOwnProperty('current')) {
            console.error(
              'Unexpected ref object provided for %s. ' +
                'Use either a ref-setter function or React.createRef().',
              getComponentName(finishedWork.type),
            );
          }
        }
  
        ref.current = instanceToUse;
      }
    }
  }
  
  function commitDetachRef(current: Fiber) {
    const currentRef = current.ref;
    if (currentRef !== null) {
      if (typeof currentRef === 'function') {
        currentRef(null);
      } else {
        currentRef.current = null;
      }
    }
  }
  
  // User-originating errors (lifecycles and refs) should not interrupt
  // deletion, so don't let them throw. Host-originating errors should
  // interrupt deletion, so it's okay
  function commitUnmount(
    finishedRoot: FiberRoot,
    current: Fiber,
    renderPriorityLevel: ReactPriorityLevel,
  ): void {
    onCommitUnmount(current);
  
    switch (current.tag) {
      case FunctionComponent:
      case ForwardRef:
      case MemoComponent:
      case SimpleMemoComponent:
      case Block: {
        const updateQueue: FunctionComponentUpdateQueue | null = (current.updateQueue: any);
        if (updateQueue !== null) {
          const lastEffect = updateQueue.lastEffect;
          if (lastEffect !== null) {
            const firstEffect = lastEffect.next;
  
            let effect = firstEffect;
            do {
              const {destroy, tag} = effect;
              if (destroy !== undefined) {
                if ((tag & HookPassive) !== NoHookEffect) {
                  enqueuePendingPassiveHookEffectUnmount(current, effect);
                } else {
                  if (
                    enableProfilerTimer &&
                    enableProfilerCommitHooks &&
                    current.mode & ProfileMode
                  ) {
                    startLayoutEffectTimer();
                    safelyCallDestroy(current, destroy);
                    recordLayoutEffectDuration(current);
                  } else {
                    safelyCallDestroy(current, destroy);
                  }
                }
              }
              effect = effect.next;
            } while (effect !== firstEffect);
          }
        }
        return;
      }
      case ClassComponent: {
        safelyDetachRef(current);
        const instance = current.stateNode;
        if (typeof instance.componentWillUnmount === 'function') {
          safelyCallComponentWillUnmount(current, instance);
        }
        return;
      }
      case HostComponent: {
        if (enableDeprecatedFlareAPI) {
          unmountDeprecatedResponderListeners(current);
        }
        if (enableCreateEventHandleAPI && current.ref !== null) {
          removeInstanceEventHandles(current.stateNode);
        }
        safelyDetachRef(current);
        return;
      }
      case HostPortal: {
        // TODO: this is recursive.
        // We are also not using this parent because
        // the portal will get pushed immediately.
        if (supportsMutation) {
          unmountHostComponents(finishedRoot, current, renderPriorityLevel);
        } else if (supportsPersistence) {
          emptyPortalContainer(current);
        }
        return;
      }
      case FundamentalComponent: {
        if (enableFundamentalAPI) {
          const fundamentalInstance = current.stateNode;
          if (fundamentalInstance !== null) {
            unmountFundamentalComponent(fundamentalInstance);
            current.stateNode = null;
          }
        }
        return;
      }
      case DehydratedFragment: {
        if (enableSuspenseCallback) {
          const hydrationCallbacks = finishedRoot.hydrationCallbacks;
          if (hydrationCallbacks !== null) {
            const onDeleted = hydrationCallbacks.onDeleted;
            if (onDeleted) {
              onDeleted((current.stateNode: SuspenseInstance));
            }
          }
        }
        return;
      }
      case ScopeComponent: {
        if (enableScopeAPI) {
          if (enableDeprecatedFlareAPI) {
            unmountDeprecatedResponderListeners(current);
          }
          const scopeInstance = current.stateNode;
          if (enableCreateEventHandleAPI && current.ref !== null) {
            removeScopeEventHandles(scopeInstance);
          }
          safelyDetachRef(current);
        }
        return;
      }
    }
  }
  
  function commitNestedUnmounts(
    finishedRoot: FiberRoot,
    root: Fiber,
    renderPriorityLevel: ReactPriorityLevel,
  ): void {
    // While we're inside a removed host node we don't want to call
    // removeChild on the inner nodes because they're removed by the top
    // call anyway. We also want to call componentWillUnmount on all
    // composites before this host node is removed from the tree. Therefore
    // we do an inner loop while we're still inside the host node.
    let node: Fiber = root;
    while (true) {
      commitUnmount(finishedRoot, node, renderPriorityLevel);
      // Visit children because they may contain more composite or host nodes.
      // Skip portals because commitUnmount() currently visits them recursively.
      if (
        node.child !== null &&
        // If we use mutation we drill down into portals using commitUnmount above.
        // If we don't use mutation we drill down into portals here instead.
        (!supportsMutation || node.tag !== HostPortal)
      ) {
        node.child.return = node;
        node = node.child;
        continue;
      }
      if (node === root) {
        return;
      }
      while (node.sibling === null) {
        if (node.return === null || node.return === root) {
          return;
        }
        node = node.return;
      }
      node.sibling.return = node.return;
      node = node.sibling;
    }
  }
  
  function detachFiberMutation(fiber: Fiber) {
    // Cut off the return pointers to disconnect it from the tree. Ideally, we
    // should clear the child pointer of the parent alternate to let this
    // get GC:ed but we don't know which for sure which parent is the current
    // one so we'll settle for GC:ing the subtree of this child. This child
    // itself will be GC:ed when the parent updates the next time.
    // Note: we cannot null out sibling here, otherwise it can cause issues
    // with findDOMNode and how it requires the sibling field to carry out
    // traversal in a later effect. See PR #16820. We now clear the sibling
    // field after effects, see: detachFiberAfterEffects.
    fiber.alternate = null;
    fiber.child = null;
    fiber.dependencies_new = null;
    fiber.firstEffect = null;
    fiber.lastEffect = null;
    fiber.memoizedProps = null;
    fiber.memoizedState = null;
    fiber.pendingProps = null;
    fiber.return = null;
    fiber.stateNode = null;
    fiber.updateQueue = null;
    if (__DEV__) {
      fiber._debugOwner = null;
    }
  }
  
  function emptyPortalContainer(current: Fiber) {
    if (!supportsPersistence) {
      return;
    }
  
    const portal: {
      containerInfo: Container,
      pendingChildren: ChildSet,
      ...
    } = current.stateNode;
    const {containerInfo} = portal;
    const emptyChildSet = createContainerChildSet(containerInfo);
    replaceContainerChildren(containerInfo, emptyChildSet);
  }
  
  function commitContainer(finishedWork: Fiber) {
    if (!supportsPersistence) {
      return;
    }
  
    switch (finishedWork.tag) {
      case ClassComponent:
      case HostComponent:
      case HostText:
      case FundamentalComponent: {
        return;
      }
      case HostRoot:
      case HostPortal: {
        const portalOrRoot: {
          containerInfo: Container,
          pendingChildren: ChildSet,
          ...
        } = finishedWork.stateNode;
        const {containerInfo, pendingChildren} = portalOrRoot;
        replaceContainerChildren(containerInfo, pendingChildren);
        return;
      }
    }
    invariant(
      false,
      'This unit of work tag should not have side-effects. This error is ' +
        'likely caused by a bug in React. Please file an issue.',
    );
  }
  
  function getHostParentFiber(fiber: Fiber): Fiber {
    let parent = fiber.return;
    while (parent !== null) {
      if (isHostParent(parent)) {
        return parent;
      }
      parent = parent.return;
    }
    invariant(
      false,
      'Expected to find a host parent. This error is likely caused by a bug ' +
        'in React. Please file an issue.',
    );
  }
  
  function isHostParent(fiber: Fiber): boolean {
    return (
      fiber.tag === HostComponent ||
      fiber.tag === HostRoot ||
      fiber.tag === HostPortal
    );
  }
  
  function getHostSibling(fiber: Fiber): ?Instance {
    // We're going to search forward into the tree until we find a sibling host
    // node. Unfortunately, if multiple insertions are done in a row we have to
    // search past them. This leads to exponential search for the next sibling.
    // TODO: Find a more efficient way to do this.
    let node: Fiber = fiber;
    siblings: while (true) {
      // If we didn't find anything, let's try the next sibling.
      while (node.sibling === null) {
        if (node.return === null || isHostParent(node.return)) {
          // If we pop out of the root or hit the parent the fiber we are the
          // last sibling.
          return null;
        }
        node = node.return;
      }
      node.sibling.return = node.return;
      node = node.sibling;
      while (
        node.tag !== HostComponent &&
        node.tag !== HostText &&
        node.tag !== DehydratedFragment
      ) {
        // If it is not host node and, we might have a host node inside it.
        // Try to search down until we find one.
        if (node.effectTag & Placement) {
          // If we don't have a child, try the siblings instead.
          continue siblings;
        }
        // If we don't have a child, try the siblings instead.
        // We also skip portals because they are not part of this host tree.
        if (node.child === null || node.tag === HostPortal) {
          continue siblings;
        } else {
          node.child.return = node;
          node = node.child;
        }
      }
      // Check if this host node is stable or about to be placed.
      if (!(node.effectTag & Placement)) {
        // Found it!
        return node.stateNode;
      }
    }
  }
  
  function commitPlacement(finishedWork: Fiber): void {
    if (!supportsMutation) {
      return;
    }
  
    // Recursively insert all host nodes into the parent.
    const parentFiber = getHostParentFiber(finishedWork);
  
    // Note: these two variables *must* always be updated together.
    let parent;
    let isContainer;
    const parentStateNode = parentFiber.stateNode;
    switch (parentFiber.tag) {
      case HostComponent:
        parent = parentStateNode;
        isContainer = false;
        break;
      case HostRoot:
        parent = parentStateNode.containerInfo;
        isContainer = true;
        break;
      case HostPortal:
        parent = parentStateNode.containerInfo;
        isContainer = true;
        break;
      case FundamentalComponent:
        if (enableFundamentalAPI) {
          parent = parentStateNode.instance;
          isContainer = false;
        }
      // eslint-disable-next-line-no-fallthrough
      default:
        invariant(
          false,
          'Invalid host parent fiber. This error is likely caused by a bug ' +
            'in React. Please file an issue.',
        );
    }
    if (parentFiber.effectTag & ContentReset) {
      // Reset the text content of the parent before doing any insertions
      resetTextContent(parent);
      // Clear ContentReset from the effect tag
      parentFiber.effectTag &= ~ContentReset;
    }
  
    const before = getHostSibling(finishedWork);
    // We only have the top Fiber that was inserted but we need to recurse down its
    // children to find all the terminal nodes.
    if (isContainer) {
      insertOrAppendPlacementNodeIntoContainer(finishedWork, before, parent);
    } else {
      insertOrAppendPlacementNode(finishedWork, before, parent);
    }
  }
  
  function insertOrAppendPlacementNodeIntoContainer(
    node: Fiber,
    before: ?Instance,
    parent: Container,
  ): void {
    const {tag} = node;
    const isHost = tag === HostComponent || tag === HostText;
    if (isHost || (enableFundamentalAPI && tag === FundamentalComponent)) {
      const stateNode = isHost ? node.stateNode : node.stateNode.instance;
      if (before) {
        insertInContainerBefore(parent, stateNode, before);
      } else {
        appendChildToContainer(parent, stateNode);
      }
    } else if (tag === HostPortal) {
      // If the insertion itself is a portal, then we don't want to traverse
      // down its children. Instead, we'll get insertions from each child in
      // the portal directly.
    } else {
      const child = node.child;
      if (child !== null) {
        insertOrAppendPlacementNodeIntoContainer(child, before, parent);
        let sibling = child.sibling;
        while (sibling !== null) {
          insertOrAppendPlacementNodeIntoContainer(sibling, before, parent);
          sibling = sibling.sibling;
        }
      }
    }
  }
  
  function insertOrAppendPlacementNode(
    node: Fiber,
    before: ?Instance,
    parent: Instance,
  ): void {
    const {tag} = node;
    const isHost = tag === HostComponent || tag === HostText;
    if (isHost || (enableFundamentalAPI && tag === FundamentalComponent)) {
      const stateNode = isHost ? node.stateNode : node.stateNode.instance;
      if (before) {
        insertBefore(parent, stateNode, before);
      } else {
        appendChild(parent, stateNode);
      }
    } else if (tag === HostPortal) {
      // If the insertion itself is a portal, then we don't want to traverse
      // down its children. Instead, we'll get insertions from each child in
      // the portal directly.
    } else {
      const child = node.child;
      if (child !== null) {
        insertOrAppendPlacementNode(child, before, parent);
        let sibling = child.sibling;
        while (sibling !== null) {
          insertOrAppendPlacementNode(sibling, before, parent);
          sibling = sibling.sibling;
        }
      }
    }
  }
  
  function unmountHostComponents(
    finishedRoot,
    current,
    renderPriorityLevel,
  ): void {
    // We only have the top Fiber that was deleted but we need to recurse down its
    // children to find all the terminal nodes.
    let node: Fiber = current;
  
    // Each iteration, currentParent is populated with node's host parent if not
    // currentParentIsValid.
    let currentParentIsValid = false;
  
    // Note: these two variables *must* always be updated together.
    let currentParent;
    let currentParentIsContainer;
  
    while (true) {
      if (!currentParentIsValid) {
        let parent = node.return;
        findParent: while (true) {
          invariant(
            parent !== null,
            'Expected to find a host parent. This error is likely caused by ' +
              'a bug in React. Please file an issue.',
          );
          const parentStateNode = parent.stateNode;
          switch (parent.tag) {
            case HostComponent:
              currentParent = parentStateNode;
              currentParentIsContainer = false;
              break findParent;
            case HostRoot:
              currentParent = parentStateNode.containerInfo;
              currentParentIsContainer = true;
              break findParent;
            case HostPortal:
              currentParent = parentStateNode.containerInfo;
              currentParentIsContainer = true;
              break findParent;
            case FundamentalComponent:
              if (enableFundamentalAPI) {
                currentParent = parentStateNode.instance;
                currentParentIsContainer = false;
              }
          }
          parent = parent.return;
        }
        currentParentIsValid = true;
      }
  
      if (node.tag === HostComponent || node.tag === HostText) {
        commitNestedUnmounts(finishedRoot, node, renderPriorityLevel);
        // After all the children have unmounted, it is now safe to remove the
        // node from the tree.
        if (currentParentIsContainer) {
          removeChildFromContainer(
            ((currentParent: any): Container),
            (node.stateNode: Instance | TextInstance),
          );
        } else {
          removeChild(
            ((currentParent: any): Instance),
            (node.stateNode: Instance | TextInstance),
          );
        }
        // Don't visit children because we already visited them.
      } else if (enableFundamentalAPI && node.tag === FundamentalComponent) {
        const fundamentalNode = node.stateNode.instance;
        commitNestedUnmounts(finishedRoot, node, renderPriorityLevel);
        // After all the children have unmounted, it is now safe to remove the
        // node from the tree.
        if (currentParentIsContainer) {
          removeChildFromContainer(
            ((currentParent: any): Container),
            (fundamentalNode: Instance),
          );
        } else {
          removeChild(
            ((currentParent: any): Instance),
            (fundamentalNode: Instance),
          );
        }
      } else if (
        enableSuspenseServerRenderer &&
        node.tag === DehydratedFragment
      ) {
        if (enableSuspenseCallback) {
          const hydrationCallbacks = finishedRoot.hydrationCallbacks;
          if (hydrationCallbacks !== null) {
            const onDeleted = hydrationCallbacks.onDeleted;
            if (onDeleted) {
              onDeleted((node.stateNode: SuspenseInstance));
            }
          }
        }
  
        // Delete the dehydrated suspense boundary and all of its content.
        if (currentParentIsContainer) {
          clearSuspenseBoundaryFromContainer(
            ((currentParent: any): Container),
            (node.stateNode: SuspenseInstance),
          );
        } else {
          clearSuspenseBoundary(
            ((currentParent: any): Instance),
            (node.stateNode: SuspenseInstance),
          );
        }
      } else if (node.tag === HostPortal) {
        if (node.child !== null) {
          // When we go into a portal, it becomes the parent to remove from.
          // We will reassign it back when we pop the portal on the way up.
          currentParent = node.stateNode.containerInfo;
          currentParentIsContainer = true;
          // Visit children because portals might contain host components.
          node.child.return = node;
          node = node.child;
          continue;
        }
      } else {
        commitUnmount(finishedRoot, node, renderPriorityLevel);
        // Visit children because we may find more host components below.
        if (node.child !== null) {
          node.child.return = node;
          node = node.child;
          continue;
        }
      }
      if (node === current) {
        return;
      }
      while (node.sibling === null) {
        if (node.return === null || node.return === current) {
          return;
        }
        node = node.return;
        if (node.tag === HostPortal) {
          // When we go out of the portal, we need to restore the parent.
          // Since we don't keep a stack of them, we will search for it.
          currentParentIsValid = false;
        }
      }
      node.sibling.return = node.return;
      node = node.sibling;
    }
  }
  
  function commitDeletion(
    finishedRoot: FiberRoot,
    current: Fiber,
    renderPriorityLevel: ReactPriorityLevel,
  ): void {
    if (supportsMutation) {
      // Recursively delete all host nodes from the parent.
      // Detach refs and call componentWillUnmount() on the whole subtree.
      unmountHostComponents(finishedRoot, current, renderPriorityLevel);
    } else {
      // Detach refs and call componentWillUnmount() on the whole subtree.
      commitNestedUnmounts(finishedRoot, current, renderPriorityLevel);
    }
    const alternate = current.alternate;
    detachFiberMutation(current);
    if (alternate !== null) {
      detachFiberMutation(alternate);
    }
  }
  
  function commitWork(current: Fiber | null, finishedWork: Fiber): void {
    if (!supportsMutation) {
      switch (finishedWork.tag) {
        case FunctionComponent:
        case ForwardRef:
        case MemoComponent:
        case SimpleMemoComponent:
        case Block: {
          // Layout effects are destroyed during the mutation phase so that all
          // destroy functions for all fibers are called before any create functions.
          // This prevents sibling component effects from interfering with each other,
          // e.g. a destroy function in one component should never override a ref set
          // by a create function in another component during the same commit.
          if (
            enableProfilerTimer &&
            enableProfilerCommitHooks &&
            finishedWork.mode & ProfileMode
          ) {
            try {
              startLayoutEffectTimer();
              commitHookEffectListUnmount(
                HookLayout | HookHasEffect,
                finishedWork,
              );
            } finally {
              recordLayoutEffectDuration(finishedWork);
            }
          } else {
            commitHookEffectListUnmount(HookLayout | HookHasEffect, finishedWork);
          }
          return;
        }
        case Profiler: {
          return;
        }
        case SuspenseComponent: {
          commitSuspenseComponent(finishedWork);
          attachSuspenseRetryListeners(finishedWork);
          return;
        }
        case SuspenseListComponent: {
          attachSuspenseRetryListeners(finishedWork);
          return;
        }
        case HostRoot: {
          if (supportsHydration) {
            const root: FiberRoot = finishedWork.stateNode;
            if (root.hydrate) {
              // We've just hydrated. No need to hydrate again.
              root.hydrate = false;
              commitHydratedContainer(root.containerInfo);
            }
          }
          break;
        }
        case OffscreenComponent:
        case LegacyHiddenComponent: {
          return;
        }
      }
  
      commitContainer(finishedWork);
      return;
    }
  
    switch (finishedWork.tag) {
      case FunctionComponent:
      case ForwardRef:
      case MemoComponent:
      case SimpleMemoComponent:
      case Block: {
        // Layout effects are destroyed during the mutation phase so that all
        // destroy functions for all fibers are called before any create functions.
        // This prevents sibling component effects from interfering with each other,
        // e.g. a destroy function in one component should never override a ref set
        // by a create function in another component during the same commit.
        if (
          enableProfilerTimer &&
          enableProfilerCommitHooks &&
          finishedWork.mode & ProfileMode
        ) {
          try {
            startLayoutEffectTimer();
            commitHookEffectListUnmount(HookLayout | HookHasEffect, finishedWork);
          } finally {
            recordLayoutEffectDuration(finishedWork);
          }
        } else {
          commitHookEffectListUnmount(HookLayout | HookHasEffect, finishedWork);
        }
        return;
      }
      case ClassComponent: {
        return;
      }
      case HostComponent: {
        const instance: Instance = finishedWork.stateNode;
        if (instance != null) {
          // Commit the work prepared earlier.
          const newProps = finishedWork.memoizedProps;
          // For hydration we reuse the update path but we treat the oldProps
          // as the newProps. The updatePayload will contain the real change in
          // this case.
          const oldProps = current !== null ? current.memoizedProps : newProps;
          const type = finishedWork.type;
          // TODO: Type the updateQueue to be specific to host components.
          const updatePayload: null | UpdatePayload = (finishedWork.updateQueue: any);
          finishedWork.updateQueue = null;
          if (updatePayload !== null) {
            commitUpdate(
              instance,
              updatePayload,
              type,
              oldProps,
              newProps,
              finishedWork,
            );
          }
          if (enableDeprecatedFlareAPI) {
            const prevListeners = oldProps.DEPRECATED_flareListeners;
            const nextListeners = newProps.DEPRECATED_flareListeners;
            if (prevListeners !== nextListeners) {
              updateDeprecatedEventListeners(nextListeners, finishedWork, null);
            }
          }
        }
        return;
      }
      case HostText: {
        invariant(
          finishedWork.stateNode !== null,
          'This should have a text node initialized. This error is likely ' +
            'caused by a bug in React. Please file an issue.',
        );
        const textInstance: TextInstance = finishedWork.stateNode;
        const newText: string = finishedWork.memoizedProps;
        // For hydration we reuse the update path but we treat the oldProps
        // as the newProps. The updatePayload will contain the real change in
        // this case.
        const oldText: string =
          current !== null ? current.memoizedProps : newText;
        commitTextUpdate(textInstance, oldText, newText);
        return;
      }
      case HostRoot: {
        if (supportsHydration) {
          const root: FiberRoot = finishedWork.stateNode;
          if (root.hydrate) {
            // We've just hydrated. No need to hydrate again.
            root.hydrate = false;
            commitHydratedContainer(root.containerInfo);
          }
        }
        return;
      }
      case Profiler: {
        return;
      }
      case SuspenseComponent: {
        commitSuspenseComponent(finishedWork);
        attachSuspenseRetryListeners(finishedWork);
        return;
      }
      case SuspenseListComponent: {
        attachSuspenseRetryListeners(finishedWork);
        return;
      }
      case IncompleteClassComponent: {
        return;
      }
      case FundamentalComponent: {
        if (enableFundamentalAPI) {
          const fundamentalInstance = finishedWork.stateNode;
          updateFundamentalComponent(fundamentalInstance);
          return;
        }
        break;
      }
      case ScopeComponent: {
        if (enableScopeAPI) {
          const scopeInstance = finishedWork.stateNode;
          if (enableDeprecatedFlareAPI) {
            const newProps = finishedWork.memoizedProps;
            const oldProps = current !== null ? current.memoizedProps : newProps;
            const prevListeners = oldProps.DEPRECATED_flareListeners;
            const nextListeners = newProps.DEPRECATED_flareListeners;
            if (prevListeners !== nextListeners || current === null) {
              updateDeprecatedEventListeners(nextListeners, finishedWork, null);
            }
          }
          prepareScopeUpdate(scopeInstance, finishedWork);
          return;
        }
        break;
      }
      case OffscreenComponent:
      case LegacyHiddenComponent: {
        const newState: OffscreenState | null = finishedWork.memoizedState;
        const isHidden = newState !== null;
        hideOrUnhideAllChildren(finishedWork, isHidden);
        return;
      }
    }
    invariant(
      false,
      'This unit of work tag should not have side-effects. This error is ' +
        'likely caused by a bug in React. Please file an issue.',
    );
  }
  
  function commitSuspenseComponent(finishedWork: Fiber) {
    const newState: SuspenseState | null = finishedWork.memoizedState;
  
    if (newState !== null) {
      markCommitTimeOfFallback();
  
      if (supportsMutation) {
        // Hide the Offscreen component that contains the primary children. TODO:
        // Ideally, this effect would have been scheduled on the Offscreen fiber
        // itself. That's how unhiding works: the Offscreen component schedules an
        // effect on itself. However, in this case, the component didn't complete,
        // so the fiber was never added to the effect list in the normal path. We
        // could have appended it to the effect list in the Suspense component's
        // second pass, but doing it this way is less complicated. This would be
        // simpler if we got rid of the effect list and traversed the tree, like
        // we're planning to do.
        const primaryChildParent: Fiber = (finishedWork.child: any);
        hideOrUnhideAllChildren(primaryChildParent, true);
      }
    }
  
    if (enableSuspenseCallback && newState !== null) {
      const suspenseCallback = finishedWork.memoizedProps.suspenseCallback;
      if (typeof suspenseCallback === 'function') {
        const wakeables: Set<Wakeable> | null = (finishedWork.updateQueue: any);
        if (wakeables !== null) {
          suspenseCallback(new Set(wakeables));
        }
      } else if (__DEV__) {
        if (suspenseCallback !== undefined) {
          console.error('Unexpected type for suspenseCallback.');
        }
      }
    }
  }
  
  function commitSuspenseHydrationCallbacks(
    finishedRoot: FiberRoot,
    finishedWork: Fiber,
  ) {
    if (!supportsHydration) {
      return;
    }
    const newState: SuspenseState | null = finishedWork.memoizedState;
    if (newState === null) {
      const current = finishedWork.alternate;
      if (current !== null) {
        const prevState: SuspenseState | null = current.memoizedState;
        if (prevState !== null) {
          const suspenseInstance = prevState.dehydrated;
          if (suspenseInstance !== null) {
            commitHydratedSuspenseInstance(suspenseInstance);
            if (enableSuspenseCallback) {
              const hydrationCallbacks = finishedRoot.hydrationCallbacks;
              if (hydrationCallbacks !== null) {
                const onHydrated = hydrationCallbacks.onHydrated;
                if (onHydrated) {
                  onHydrated(suspenseInstance);
                }
              }
            }
          }
        }
      }
    }
  }
  
  function attachSuspenseRetryListeners(finishedWork: Fiber) {
    // If this boundary just timed out, then it will have a set of wakeables.
    // For each wakeable, attach a listener so that when it resolves, React
    // attempts to re-render the boundary in the primary (pre-timeout) state.
    const wakeables: Set<Wakeable> | null = (finishedWork.updateQueue: any);
    if (wakeables !== null) {
      finishedWork.updateQueue = null;
      let retryCache = finishedWork.stateNode;
      if (retryCache === null) {
        retryCache = finishedWork.stateNode = new PossiblyWeakSet();
      }
      wakeables.forEach(wakeable => {
        // Memoize using the boundary fiber to prevent redundant listeners.
        let retry = resolveRetryWakeable.bind(null, finishedWork, wakeable);
        if (!retryCache.has(wakeable)) {
          if (enableSchedulerTracing) {
            if (wakeable.__reactDoNotTraceInteractions !== true) {
              retry = Schedule_tracing_wrap(retry);
            }
          }
          retryCache.add(wakeable);
          wakeable.then(retry, retry);
        }
      });
    }
  }
  
  // This function detects when a Suspense boundary goes from visible to hidden.
  // It returns false if the boundary is already hidden.
  // TODO: Use an effect tag.
  export function isSuspenseBoundaryBeingHidden(
    current: Fiber | null,
    finishedWork: Fiber,
  ): boolean {
    if (current !== null) {
      const oldState: SuspenseState | null = current.memoizedState;
      if (oldState === null || oldState.dehydrated !== null) {
        const newState: SuspenseState | null = finishedWork.memoizedState;
        return newState !== null && newState.dehydrated === null;
      }
    }
    return false;
  }
  
  function commitResetTextContent(current: Fiber) {
    if (!supportsMutation) {
      return;
    }
    resetTextContent(current.stateNode);
  }
  
  export {
    commitBeforeMutationLifeCycles,
    commitResetTextContent,
    commitPlacement,
    commitDeletion,
    commitWork,
    commitLifeCycles,
    commitAttachRef,
    commitDetachRef,
  };
  