[Draft] Add feature flag: enableStrongMemoryCleanup

Add a feature flag that will test doing a recursive
clean of an unmount node. This will disconnect the
fiber graph making leaks less severe.

packages/react-art/src/ReactARTHostConfig.js

@@ -471,3 +471,7 @@ export function afterActiveInstanceBlur() {
 export function preparePortalMount(portalInstance: any): void {
   // noop
 }
+
+export function unmountNode(node: any): void {
+  // noop
+}

packages/react-dom/src/client/ReactDOMComponentTree.js

@@ -43,6 +43,17 @@ const internalEventHandlersKey = '__reactEvents$' + randomKey;
 const internalEventHandlerListenersKey = '__reactListeners$' + randomKey;
 const internalEventHandlesSetKey = '__reactHandles$' + randomKey;
 
+export function unmountNode(
+  node: Instance | TextInstance | SuspenseInstance | ReactScopeInstance,
+): void {
+  delete (node: any)[internalInstanceKey];
+  delete (node: any)[internalPropsKey];
+  delete (node: any)[internalContainerInstanceKey];
+  delete (node: any)[internalEventHandlersKey];
+  delete (node: any)[internalEventHandlerListenersKey];
+  delete (node: any)[internalEventHandlesSetKey];
+}
+
 export function precacheFiberNode(
   hostInst: Fiber,
   node: Instance | TextInstance | SuspenseInstance | ReactScopeInstance,

packages/react-dom/src/client/ReactDOMHostConfig.js

@@ -24,6 +24,7 @@ import {
   getFiberFromScopeInstance,
   getInstanceFromNode as getInstanceFromNodeDOMTree,
   isContainerMarkedAsRoot,
+  unmountNode as unmountNodeFromDOMTree,
 } from './ReactDOMComponentTree';
 import {hasRole} from './DOMAccessibilityRoles';
 import {
@@ -1209,3 +1210,7 @@ export function setupIntersectionObserver(
     },
   };
 }
+
+export function unmountNode(node: any): void {
+  unmountNodeFromDOMTree(node);
+}

packages/react-native-renderer/src/ReactFabricHostConfig.js

@@ -481,3 +481,7 @@ export function afterActiveInstanceBlur() {
 export function preparePortalMount(portalInstance: Instance): void {
   // noop
 }
+
+export function unmountNode(node: any): void {
+  // noop
+}

packages/react-native-renderer/src/ReactNativeHostConfig.js

@@ -538,3 +538,7 @@ export function afterActiveInstanceBlur() {
 export function preparePortalMount(portalInstance: Instance): void {
   // noop
 }
+
+export function unmountNode(node: any): void {
+  // noop
+}

packages/react-noop-renderer/src/createReactNoop.js

@@ -420,6 +420,8 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
     getInstanceFromScope() {
       throw new Error('Not yet implemented.');
     },
+
+    unmountNode() {},
   };
 
   const hostConfig = useMutation

packages/react-reconciler/src/ReactFiberCommitWork.new.js

@@ -35,6 +35,7 @@ import {
   enableSuspenseCallback,
   enableScopeAPI,
   enableStrictEffects,
+  enableStrongMemoryCleanup,
 } from 'shared/ReactFeatureFlags';
 import {
   FunctionComponent,
@@ -60,6 +61,7 @@ import {
   hasCaughtError,
   clearCaughtError,
 } from 'shared/ReactErrorUtils';
+import {unmountNode} from './ReactFiberHostConfig';
 import {
   NoFlags,
   ContentReset,
@@ -1212,9 +1214,24 @@ function detachFiberMutation(fiber: Fiber) {
   fiber.return = null;
 }
 
-export function detachFiberAfterEffects(fiber: Fiber): void {
+export function detachFiberAfterEffects(
+  fiber: Fiber,
+  recurseIntoSibbling: ?boolean,
+): void {
   // Null out fields to improve GC for references that may be lingering (e.g. DevTools).
   // Note that we already cleared the return pointer in detachFiberMutation().
+  if (enableStrongMemoryCleanup) {
+    if (fiber.child) {
+      detachFiberAfterEffects(fiber.child, true);
+    }
+    if (fiber.sibling && recurseIntoSibbling === true) {
+      detachFiberAfterEffects(fiber.sibling, true);
+    }
+    if (fiber.stateNode) {
+      unmountNode(fiber.stateNode);
+    }
+    fiber.return = null;
+  }
   fiber.alternate = null;
   fiber.child = null;
   fiber.deletions = null;

packages/react-reconciler/src/ReactFiberCommitWork.old.js

@@ -35,6 +35,7 @@ import {
   enableSuspenseCallback,
   enableScopeAPI,
   enableStrictEffects,
+  enableStrongMemoryCleanup,
 } from 'shared/ReactFeatureFlags';
 import {
   FunctionComponent,
@@ -60,6 +61,7 @@ import {
   hasCaughtError,
   clearCaughtError,
 } from 'shared/ReactErrorUtils';
+import {unmountNode} from './ReactFiberHostConfig';
 import {
   NoFlags,
   ContentReset,
@@ -1212,9 +1214,24 @@ function detachFiberMutation(fiber: Fiber) {
   fiber.return = null;
 }
 
-export function detachFiberAfterEffects(fiber: Fiber): void {
+export function detachFiberAfterEffects(
+  fiber: Fiber,
+  recurseIntoSibbling: ?boolean,
+): void {
   // Null out fields to improve GC for references that may be lingering (e.g. DevTools).
   // Note that we already cleared the return pointer in detachFiberMutation().
+  if (enableStrongMemoryCleanup) {
+    if (fiber.child) {
+      detachFiberAfterEffects(fiber.child, true);
+    }
+    if (fiber.sibling && recurseIntoSibbling === true) {
+      detachFiberAfterEffects(fiber.sibling, true);
+    }
+    if (fiber.stateNode) {
+      unmountNode(fiber.stateNode);
+    }
+    fiber.return = null;
+  }
   fiber.alternate = null;
   fiber.child = null;
   fiber.deletions = null;

packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js

@@ -73,6 +73,7 @@ export const preparePortalMount = $$$hostConfig.preparePortalMount;
 export const prepareScopeUpdate = $$$hostConfig.preparePortalMount;
 export const getInstanceFromScope = $$$hostConfig.getInstanceFromScope;
 export const getCurrentEventPriority = $$$hostConfig.getCurrentEventPriority;
+export const unmountNode = $$$hostConfig.unmountNode;
 
 // -------------------
 //      Microtasks

packages/react-test-renderer/src/ReactTestHostConfig.js

@@ -360,3 +360,7 @@ export function prepareScopeUpdate(scopeInstance: Object, inst: Object): void {
 export function getInstanceFromScope(scopeInstance: Object): null | Object {
   return nodeToInstanceMap.get(scopeInstance) || null;
 }
+
+export function unmountNode(node: any): void {
+  // noop
+}

packages/shared/ReactFeatureFlags.js

@@ -112,6 +112,9 @@ export const disableNativeComponentFrames = false;
 // If there are no still-mounted boundaries, the errors should be rethrown.
 export const skipUnmountedBoundaries = false;
 
+// When a node is unmounted, recurse into the Fiber subtree and clean out references.
+export const enableStrongMemoryCleanup = false;
+
 // --------------------------
 // Future APIs to be deprecated
 // --------------------------

packages/shared/forks/ReactFeatureFlags.native-fb.js

@@ -46,6 +46,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.native-oss.js

@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.test-renderer.js

@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.test-renderer.native.js

@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.test-renderer.www.js

@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.testing.js

@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
+export const enableStrongMemoryCleanup = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.testing.www.js

@@ -45,6 +45,7 @@ export const enableLegacyFBSupport = !__EXPERIMENTAL__;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = true;
+export const enableStrongMemoryCleanup = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.www-dynamic.js

@@ -52,6 +52,7 @@ export const disableNativeComponentFrames = false;
 export const createRootStrictEffectsByDefault = false;
 export const enableStrictEffects = false;
 export const enableUseRefAccessWarning = __VARIANT__;
+export const enableStrongMemoryCleanup = __VARIANT__;
 
 export const enableProfilerNestedUpdateScheduledHook = __VARIANT__;
 export const disableSchedulerTimeoutInWorkLoop = __VARIANT__;

packages/shared/forks/ReactFeatureFlags.www.js

@@ -33,6 +33,7 @@ export const {
   disableSchedulerTimeoutInWorkLoop,
   enableSyncMicroTasks,
   enableLazyContextPropagation,
+  enableStrongMemoryCleanup,
 } = dynamicFeatureFlags;
 
 // On WWW, __EXPERIMENTAL__ is used for a new modern build.