Remove Reconciler fork (2/2) (#25775)

We've heard from multiple contributors that the Reconciler forking
mechanism was confusing and/or annoying to deal with. Since it's
currently unused and there's no immediate plans to start using it again,
this removes the forking.

Fully removing the fork is split into 2 steps to preserve file history:

**#25774 previous PR that did the bulk of the work:**
- remove `enableNewReconciler` feature flag.
- remove `unstable_isNewReconciler` export
- remove eslint rules for cross fork imports
- remove `*.new.js` files and update imports
- merge non-suffixed files into `*.old` files where both exist
(sometimes types were defined there)

**This PR**
- rename `*.old` files

packages/react-art/src/ReactART.js

@@ -12,7 +12,7 @@ import {
   createContainer,
   updateContainer,
   injectIntoDevTools,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';
 import Transform from 'art/core/transform';
 import Mode from 'art/modes/current';
 import FastNoSideEffects from 'art/modes/fast-noSideEffects';

packages/react-art/src/ReactARTHostConfig.js

@@ -10,7 +10,7 @@ import Mode from 'art/modes/current';
 
 import {TYPES, EVENT_TYPES, childrenAsString} from './ReactARTInternals';
 
-import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities.old';
+import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 const pooledTransform = new Transform();
 

packages/react-dom-bindings/src/client/ReactDOMFloatClient.js

@@ -29,7 +29,7 @@ import {
   markNodeAsResource,
 } from './ReactDOMComponentTree';
 import {HTML_NAMESPACE, SVG_NAMESPACE} from '../shared/DOMNamespaces';
-import {getCurrentRootHostContainer} from 'react-reconciler/src/ReactFiberHostContext.old';
+import {getCurrentRootHostContainer} from 'react-reconciler/src/ReactFiberHostContext';
 
 // The resource types we support. currently they match the form for the as argument.
 // In the future this may need to change, especially when modules / scripts are supported

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

@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {EventPriority} from 'react-reconciler/src/ReactEventPriorities.old';
+import type {EventPriority} from 'react-reconciler/src/ReactEventPriorities';
 import type {DOMEventName} from '../events/DOMEventNames';
 import type {Fiber, FiberRoot} from 'react-reconciler/src/ReactInternalTypes';
 import type {
@@ -81,7 +81,7 @@ import {
 } from 'react-reconciler/src/ReactWorkTags';
 import {listenToAllSupportedEvents} from '../events/DOMPluginEventSystem';
 
-import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities.old';
+import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 // TODO: Remove this deep import when we delete the legacy root API
 import {ConcurrentMode, NoMode} from 'react-reconciler/src/ReactTypeOfMode';

packages/react-dom-bindings/src/events/ReactDOMEventListener.js

@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {EventPriority} from 'react-reconciler/src/ReactEventPriorities.old';
+import type {EventPriority} from 'react-reconciler/src/ReactEventPriorities';
 import type {AnyNativeEvent} from '../events/PluginModuleType';
 import type {Fiber, FiberRoot} from 'react-reconciler/src/ReactInternalTypes';
 import type {Container, SuspenseInstance} from '../client/ReactDOMHostConfig';
@@ -52,7 +52,7 @@ import {
   IdleEventPriority,
   getCurrentUpdatePriority,
   setCurrentUpdatePriority,
-} from 'react-reconciler/src/ReactEventPriorities.old';
+} from 'react-reconciler/src/ReactEventPriorities';
 import ReactSharedInternals from 'shared/ReactSharedInternals';
 import {isRootDehydrated} from 'react-reconciler/src/ReactFiberShellHydration';
 

packages/react-dom-bindings/src/events/ReactDOMEventReplaying.js

@@ -12,7 +12,7 @@ import type {Container, SuspenseInstance} from '../client/ReactDOMHostConfig';
 import type {DOMEventName} from '../events/DOMEventNames';
 import type {EventSystemFlags} from './EventSystemFlags';
 import type {FiberRoot} from 'react-reconciler/src/ReactInternalTypes';
-import type {EventPriority} from 'react-reconciler/src/ReactEventPriorities.old';
+import type {EventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 import {enableCapturePhaseSelectiveHydrationWithoutDiscreteEventReplay} from 'shared/ReactFeatureFlags';
 import {
@@ -35,7 +35,7 @@ import {
   getClosestInstanceFromNode,
 } from '../client/ReactDOMComponentTree';
 import {HostRoot, SuspenseComponent} from 'react-reconciler/src/ReactWorkTags';
-import {isHigherEventPriority} from 'react-reconciler/src/ReactEventPriorities.old';
+import {isHigherEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 import {isRootDehydrated} from 'react-reconciler/src/ReactFiberShellHydration';
 
 let _attemptSynchronousHydration: (fiber: Object) => void;

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

@@ -43,11 +43,11 @@ import {
   attemptDiscreteHydration,
   attemptContinuousHydration,
   attemptHydrationAtCurrentPriority,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';
 import {
   runWithPriority,
   getCurrentUpdatePriority,
-} from 'react-reconciler/src/ReactEventPriorities.old';
+} from 'react-reconciler/src/ReactEventPriorities';
 import {createPortal as createPortalImpl} from 'react-reconciler/src/ReactPortal';
 import {canUseDOM} from 'shared/ExecutionEnvironment';
 import ReactVersion from 'shared/ReactVersion';

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

@@ -37,7 +37,7 @@ import {
   getPublicRootInstance,
   findHostInstance,
   findHostInstanceWithWarning,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';
 import {LegacyRoot} from 'react-reconciler/src/ReactRootTags';
 import getComponentNameFromType from 'shared/getComponentNameFromType';
 import ReactSharedInternals from 'shared/ReactSharedInternals';

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

@@ -76,7 +76,7 @@ import {
   registerMutableSourceForHydration,
   flushSync,
   isAlreadyRendering,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';
 import {ConcurrentRoot} from 'react-reconciler/src/ReactRootTags';
 
 /* global reportError */

packages/react-dom/unstable_testing.classic.fb.js

@@ -19,4 +19,4 @@ export {
   findBoundingRects,
   focusWithin,
   observeVisibleRects,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';

packages/react-dom/unstable_testing.experimental.js

@@ -19,4 +19,4 @@ export {
   findBoundingRects,
   focusWithin,
   observeVisibleRects,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';

packages/react-dom/unstable_testing.js

@@ -19,4 +19,4 @@ export {
   findBoundingRects,
   focusWithin,
   observeVisibleRects,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';

packages/react-dom/unstable_testing.modern.fb.js

@@ -19,4 +19,4 @@ export {
   findBoundingRects,
   focusWithin,
   observeVisibleRects,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';

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

@@ -22,7 +22,7 @@ import {
   updateContainer,
   injectIntoDevTools,
   getPublicRootInstance,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';
 
 import {createPortal as createPortalImpl} from 'react-reconciler/src/ReactPortal';
 import {setBatchingImplementation} from './legacy-events/ReactGenericBatching';

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

@@ -26,7 +26,7 @@ import {dispatchEvent} from './ReactFabricEventEmitter';
 import {
   DefaultEventPriority,
   DiscreteEventPriority,
-} from 'react-reconciler/src/ReactEventPriorities.old';
+} from 'react-reconciler/src/ReactEventPriorities';
 
 // Modules provided by RN:
 import {

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

@@ -24,7 +24,7 @@ import {
 } from './ReactNativeComponentTree';
 import ReactNativeFiberHostComponent from './ReactNativeFiberHostComponent';
 
-import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities.old';
+import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 const {get: getViewConfigForType} = ReactNativeViewConfigRegistry;
 

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

@@ -22,7 +22,7 @@ import {
   updateContainer,
   injectIntoDevTools,
   getPublicRootInstance,
-} from 'react-reconciler/src/ReactFiberReconciler.old';
+} from 'react-reconciler/src/ReactFiberReconciler';
 // TODO: direct imports like some-package/src/* are bad. Fix me.
 import {getStackByFiberInDevAndProd} from 'react-reconciler/src/ReactFiberComponentStack';
 import {createPortal as createPortalImpl} from 'react-reconciler/src/ReactPortal';

packages/react-reconciler/index.js

@@ -7,4 +7,4 @@
  * @flow
  */
 
-export * from './src/ReactFiberReconciler.old';
+export * from './src/ReactFiberReconciler';

packages/react-reconciler/src/DebugTracing.js

@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {Lane, Lanes} from './ReactFiberLane.old';
+import type {Lane, Lanes} from './ReactFiberLane';
 import type {Wakeable} from 'shared/ReactTypes';
 
 import {enableDebugTracing} from 'shared/ReactFeatureFlags';

packages/react-reconciler/src/ReactChildFiber.old.js → packages/react-reconciler/src/ReactChildFiber.js

@@ -10,7 +10,7 @@
 import type {ReactElement} from 'shared/ReactElementType';
 import type {ReactPortal} from 'shared/ReactTypes';
 import type {Fiber} from './ReactInternalTypes';
-import type {Lanes} from './ReactFiberLane.old';
+import type {Lanes} from './ReactFiberLane';
 
 import getComponentNameFromFiber from 'react-reconciler/src/getComponentNameFromFiber';
 import {
@@ -38,11 +38,11 @@ import {
   createFiberFromFragment,
   createFiberFromText,
   createFiberFromPortal,
-} from './ReactFiber.old';
-import {isCompatibleFamilyForHotReloading} from './ReactFiberHotReloading.old';
+} from './ReactFiber';
+import {isCompatibleFamilyForHotReloading} from './ReactFiberHotReloading';
 import {StrictLegacyMode} from './ReactTypeOfMode';
-import {getIsHydrating} from './ReactFiberHydrationContext.old';
-import {pushTreeFork} from './ReactFiberTreeContext.old';
+import {getIsHydrating} from './ReactFiberHydrationContext';
+import {pushTreeFork} from './ReactFiberTreeContext';
 
 let didWarnAboutMaps;
 let didWarnAboutGenerators;

packages/react-reconciler/src/ReactEventPriorities.old.js → packages/react-reconciler/src/ReactEventPriorities.js

@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {Lane, Lanes} from './ReactFiberLane.old';
+import type {Lane, Lanes} from './ReactFiberLane';
 
 import {
   NoLane,
@@ -17,7 +17,7 @@ import {
   IdleLane,
   getHighestPriorityLane,
   includesNonIdleWork,
-} from './ReactFiberLane.old';
+} from './ReactFiberLane';
 
 export opaque type EventPriority = Lane;
 

packages/react-reconciler/src/ReactFiber.old.js → packages/react-reconciler/src/ReactFiber.js

@@ -13,13 +13,13 @@ import type {Fiber} from './ReactInternalTypes';
 import type {RootTag} from './ReactRootTags';
 import type {WorkTag} from './ReactWorkTags';
 import type {TypeOfMode} from './ReactTypeOfMode';
-import type {Lanes} from './ReactFiberLane.old';
+import type {Lanes} from './ReactFiberLane';
 import type {SuspenseInstance} from './ReactFiberHostConfig';
 import type {
   OffscreenProps,
   OffscreenInstance,
 } from './ReactFiberOffscreenComponent';
-import type {TracingMarkerInstance} from './ReactFiberTracingMarkerComponent.old';
+import type {TracingMarkerInstance} from './ReactFiberTracingMarkerComponent';
 
 import {
   supportsResources,
@@ -72,13 +72,13 @@ import {
 } from './ReactWorkTags';
 import {OffscreenVisible} from './ReactFiberOffscreenComponent';
 import getComponentNameFromFiber from 'react-reconciler/src/getComponentNameFromFiber';
-import {isDevToolsPresent} from './ReactFiberDevToolsHook.old';
+import {isDevToolsPresent} from './ReactFiberDevToolsHook';
 import {
   resolveClassForHotReloading,
   resolveFunctionForHotReloading,
   resolveForwardRefForHotReloading,
-} from './ReactFiberHotReloading.old';
-import {NoLanes} from './ReactFiberLane.old';
+} from './ReactFiberHotReloading';
+import {NoLanes} from './ReactFiberLane';
 import {
   NoMode,
   ConcurrentMode,
@@ -106,9 +106,9 @@ import {
   REACT_CACHE_TYPE,
   REACT_TRACING_MARKER_TYPE,
 } from 'shared/ReactSymbols';
-import {TransitionTracingMarker} from './ReactFiberTracingMarkerComponent.old';
-import {detachOffscreenInstance} from './ReactFiberCommitWork.old';
-import {getHostContext} from './ReactFiberHostContext.old';
+import {TransitionTracingMarker} from './ReactFiberTracingMarkerComponent';
+import {detachOffscreenInstance} from './ReactFiberCommitWork';
+import {getHostContext} from './ReactFiberHostContext';
 
 export type {Fiber};
 

packages/react-reconciler/src/ReactFiberAct.old.js → packages/react-reconciler/src/ReactFiberAct.js

@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {Fiber} from './ReactFiber.old';
+import type {Fiber} from './ReactFiber';
 
 import ReactSharedInternals from 'shared/ReactSharedInternals';