Move priorities to separate import to break cycle

packages/react-art/src/ReactARTHostConfig.js

@@ -7,17 +7,11 @@
 
 import Transform from 'art/core/transform';
 import Mode from 'art/modes/current';
-import {enableNewReconciler} from 'shared/ReactFeatureFlags';
 import invariant from 'shared/invariant';
 
 import {TYPES, EVENT_TYPES, childrenAsString} from './ReactARTInternals';
 
-import {DefaultLanePriority as DefaultLanePriority_old} from 'react-reconciler/src/ReactFiberLane.old';
-import {DefaultLanePriority as DefaultLanePriority_new} from 'react-reconciler/src/ReactFiberLane.new';
-
-const DefaultLanePriority = enableNewReconciler
-  ? DefaultLanePriority_new
-  : DefaultLanePriority_old;
+import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 const pooledTransform = new Transform();
 
@@ -347,7 +341,7 @@ export function shouldSetTextContent(type, props) {
 }
 
 export function getCurrentEventPriority() {
-  return DefaultLanePriority;
+  return DefaultEventPriority;
 }
 
 // The ART renderer is secondary to the React DOM renderer.

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

@@ -67,17 +67,11 @@ import {
   enableSuspenseServerRenderer,
   enableCreateEventHandleAPI,
   enableScopeAPI,
-  enableNewReconciler,
 } from 'shared/ReactFeatureFlags';
 import {HostComponent, HostText} from 'react-reconciler/src/ReactWorkTags';
 import {listenToAllSupportedEvents} from '../events/DOMPluginEventSystem';
 
-import {DefaultLanePriority as DefaultLanePriority_old} from 'react-reconciler/src/ReactFiberLane.old';
-import {DefaultLanePriority as DefaultLanePriority_new} from 'react-reconciler/src/ReactFiberLane.new';
-
-const DefaultLanePriority = enableNewReconciler
-  ? DefaultLanePriority_new
-  : DefaultLanePriority_old;
+import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 export type Type = string;
 export type Props = {
@@ -385,7 +379,7 @@ export function createTextInstance(
 export function getCurrentEventPriority(): * {
   const currentEvent = window.event;
   if (currentEvent === undefined) {
-    return DefaultLanePriority;
+    return DefaultEventPriority;
   }
   return getEventPriority(currentEvent.type);
 }

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

@@ -14,6 +14,7 @@ import type {
 } from 'react-reconciler/src/ReactInternalTypes';
 import type {Container, SuspenseInstance} from '../client/ReactDOMHostConfig';
 import type {DOMEventName} from '../events/DOMEventNames';
+import type {LanePriority} from 'react-reconciler/src/ReactFiberLane.new';
 
 import {
   isReplayableDiscreteEvent,
@@ -49,18 +50,13 @@ import {
 
 import {
   InputContinuousLanePriority as InputContinuousLanePriority_old,
-  DefaultLanePriority as DefaultLanePriority_old,
   getCurrentUpdateLanePriority as getCurrentUpdateLanePriority_old,
   setCurrentUpdateLanePriority as setCurrentUpdateLanePriority_old,
 } from 'react-reconciler/src/ReactFiberLane.old';
 import {
   InputContinuousLanePriority as InputContinuousLanePriority_new,
-  DefaultLanePriority as DefaultLanePriority_new,
   getCurrentUpdateLanePriority as getCurrentUpdateLanePriority_new,
   setCurrentUpdateLanePriority as setCurrentUpdateLanePriority_new,
-  SyncLanePriority,
-  IdleLanePriority,
-  NoLanePriority,
 } from 'react-reconciler/src/ReactFiberLane.new';
 import {getCurrentPriorityLevel as getCurrentPriorityLevel_old} from 'react-reconciler/src/SchedulerWithReactIntegration.old';
 import {
@@ -71,14 +67,16 @@ import {
   NormalPriority as NormalSchedulerPriority,
   UserBlockingPriority as UserBlockingSchedulerPriority,
 } from 'react-reconciler/src/SchedulerWithReactIntegration.new';
-import type {LanePriority} from 'react-reconciler/src/ReactFiberLane.new';
+import {
+  DiscreteEventPriority,
+  ContinuousEventPriority,
+  DefaultEventPriority,
+  IdleEventPriority,
+} from 'react-reconciler/src/ReactEventPriorities';
 
 const InputContinuousLanePriority = enableNewReconciler
   ? InputContinuousLanePriority_new
   : InputContinuousLanePriority_old;
-const DefaultLanePriority = enableNewReconciler
-  ? DefaultLanePriority_new
-  : DefaultLanePriority_old;
 const getCurrentUpdateLanePriority = enableNewReconciler
   ? getCurrentUpdateLanePriority_new
   : getCurrentUpdateLanePriority_old;
@@ -94,17 +92,17 @@ function schedulerPriorityToLanePriority(
 ): LanePriority {
   switch (schedulerPriorityLevel) {
     case ImmediateSchedulerPriority:
-      return SyncLanePriority;
+      return DiscreteEventPriority;
     case UserBlockingSchedulerPriority:
-      return InputContinuousLanePriority;
+      return ContinuousEventPriority;
     case NormalSchedulerPriority:
     case LowSchedulerPriority:
       // TODO: Handle LowSchedulerPriority, somehow. Maybe the same lane as hydration.
-      return DefaultLanePriority;
+      return DefaultEventPriority;
     case IdleSchedulerPriority:
-      return IdleLanePriority;
+      return IdleEventPriority;
     default:
-      return NoLanePriority;
+      return DefaultEventPriority;
   }
 }
 
@@ -142,13 +140,13 @@ export function createEventListenerWrapperWithPriority(
   const eventPriority = getEventPriority(domEventName);
   let listenerWrapper;
   switch (eventPriority) {
-    case SyncLanePriority:
+    case DiscreteEventPriority:
       listenerWrapper = dispatchDiscreteEvent;
       break;
-    case InputContinuousLanePriority:
+    case ContinuousEventPriority:
       listenerWrapper = dispatchContinuousEvent;
       break;
-    case DefaultLanePriority:
+    case DefaultEventPriority:
     default:
       listenerWrapper = dispatchEvent;
       break;
@@ -407,7 +405,7 @@ export function getEventPriority(domEventName: DOMEventName): * {
     case 'popstate':
     case 'select':
     case 'selectstart':
-      return SyncLanePriority;
+      return DiscreteEventPriority;
     case 'drag':
     case 'dragenter':
     case 'dragexit':
@@ -427,7 +425,7 @@ export function getEventPriority(domEventName: DOMEventName): * {
     // eslint-disable-next-line no-fallthrough
     case 'mouseenter':
     case 'mouseleave':
-      return InputContinuousLanePriority;
+      return ContinuousEventPriority;
     case 'message': {
       // We might be in the Scheduler callback.
       // Eventually this mechanism will be replaced by a check
@@ -436,6 +434,6 @@ export function getEventPriority(domEventName: DOMEventName): * {
       return schedulerPriorityToLanePriority(schedulerPriority);
     }
     default:
-      return DefaultLanePriority;
+      return DefaultEventPriority;
   }
 }

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

@@ -21,17 +21,11 @@ import type {
 import {mountSafeCallback_NOT_REALLY_SAFE} from './NativeMethodsMixinUtils';
 import {create, diff} from './ReactNativeAttributePayload';
 
-import {enableNewReconciler} from 'shared/ReactFeatureFlags';
 import invariant from 'shared/invariant';
 
 import {dispatchEvent} from './ReactFabricEventEmitter';
 
-import {DefaultLanePriority as DefaultLanePriority_old} from 'react-reconciler/src/ReactFiberLane.old';
-import {DefaultLanePriority as DefaultLanePriority_new} from 'react-reconciler/src/ReactFiberLane.new';
-
-const DefaultLanePriority = enableNewReconciler
-  ? DefaultLanePriority_new
-  : DefaultLanePriority_old;
+import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 // Modules provided by RN:
 import {
@@ -349,7 +343,7 @@ export function shouldSetTextContent(type: string, props: Props): boolean {
 }
 
 export function getCurrentEventPriority(): * {
-  return DefaultLanePriority;
+  return DefaultEventPriority;
 }
 
 // The Fabric renderer is secondary to the existing React Native renderer.

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

@@ -10,7 +10,6 @@
 import type {TouchedViewDataAtPoint} from './ReactNativeTypes';
 
 import invariant from 'shared/invariant';
-import {enableNewReconciler} from 'shared/ReactFeatureFlags';
 
 // Modules provided by RN:
 import {
@@ -27,12 +26,7 @@ import {
 } from './ReactNativeComponentTree';
 import ReactNativeFiberHostComponent from './ReactNativeFiberHostComponent';
 
-import {DefaultLanePriority as DefaultLanePriority_old} from 'react-reconciler/src/ReactFiberLane.old';
-import {DefaultLanePriority as DefaultLanePriority_new} from 'react-reconciler/src/ReactFiberLane.new';
-
-const DefaultLanePriority = enableNewReconciler
-  ? DefaultLanePriority_new
-  : DefaultLanePriority_old;
+import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 const {get: getViewConfigForType} = ReactNativeViewConfigRegistry;
 
@@ -268,7 +262,7 @@ export function shouldSetTextContent(type: string, props: Props): boolean {
 }
 
 export function getCurrentEventPriority(): * {
-  return DefaultLanePriority;
+  return DefaultEventPriority;
 }
 
 // -------------------

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

@@ -27,6 +27,9 @@ import ReactSharedInternals from 'shared/ReactSharedInternals';
 import enqueueTask from 'shared/enqueueTask';
 const {IsSomeRendererActing} = ReactSharedInternals;
 
+// TODO: Publish public entry point that exports the event priority constants
+const DefaultEventPriority = 8;
+
 type Container = {
   rootID: string,
   children: Array<Instance | TextInstance>,
@@ -587,7 +590,7 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
   const roots = new Map();
   const DEFAULT_ROOT_ID = '<default>';
 
-  let currentEventPriority = NoopRenderer.DefaultEventPriority;
+  let currentEventPriority = DefaultEventPriority;
 
   function childToJSX(child, text) {
     if (text !== null) {

packages/react-reconciler/README.md

@@ -219,10 +219,16 @@ This is a property (not a function) that should be set to `true` if your rendere
 To implement this method, you'll need some constants available on the _returned_ `Renderer` object:
 
 ```js
+import {
+  DiscreteEventPriority,
+  ContinuousEventPriority,
+  DefaultEventPriority,
+} from './ReactFiberReconciler/src/ReactEventPriorities';
+
 const HostConfig = {
   // ...
   getCurrentEventPriority() {
-    return MyRenderer.DefaultEventPriority;
+    return DefaultEventPriority;
   },
   // ...
 }
@@ -232,11 +238,11 @@ const MyRenderer = Reconciler(HostConfig);
 
 The constant you return depends on which event, if any, is being handled right now. (In the browser, you can check this using `window.event && window.event.type`).
 
-* **Discrete events:** If the active event is _directly caused by the user_ (such as mouse and keyboard events) and _each event in a sequence is intentional_ (e.g. `click`), return `MyRenderer.DiscreteEventPriority`. This tells React that they should interrupt any background work and cannot be batched across time.
+* **Discrete events:** If the active event is _directly caused by the user_ (such as mouse and keyboard events) and _each event in a sequence is intentional_ (e.g. `click`), return `DiscreteEventPriority`. This tells React that they should interrupt any background work and cannot be batched across time.
 
-* **Continuous events:** If the active event is _directly caused by the user_ but _the user can't distinguish between individual events in a sequence_ (e.g. `mouseover`), return `MyRenderer.ContinuousEventPriority`. This tells React they should interrupt any background work but can be batched across time.
+* **Continuous events:** If the active event is _directly caused by the user_ but _the user can't distinguish between individual events in a sequence_ (e.g. `mouseover`), return `ContinuousEventPriority`. This tells React they should interrupt any background work but can be batched across time.
 
-* **Other events / No active event:** In all other cases, return `MyRenderer.DefaultEventPriority`. This tells React that this event is considered background work, and interactive events will be prioritized over it.
+* **Other events / No active event:** In all other cases, return `DefaultEventPriority`. This tells React that this event is considered background work, and interactive events will be prioritized over it.
 
 You can consult the `getCurrentEventPriority()` implementation in `ReactDOMHostConfig.js` for a reference implementation.
 

packages/react-reconciler/src/ReactEventPriorities.js

@@ -0,0 +1,37 @@
+/**
+ * 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 {enableNewReconciler} from 'shared/ReactFeatureFlags';
+
+import {
+  DiscreteEventPriority as DiscreteEventPriority_old,
+  ContinuousEventPriority as ContinuousEventPriority_old,
+  DefaultEventPriority as DefaultEventPriority_old,
+  IdleEventPriority as IdleEventPriority_old,
+} from './ReactEventPriorities.old';
+
+import {
+  DiscreteEventPriority as DiscreteEventPriority_new,
+  ContinuousEventPriority as ContinuousEventPriority_new,
+  DefaultEventPriority as DefaultEventPriority_new,
+  IdleEventPriority as IdleEventPriority_new,
+} from './ReactEventPriorities.new';
+
+export const DiscreteEventPriority = enableNewReconciler
+  ? DiscreteEventPriority_new
+  : DiscreteEventPriority_old;
+export const ContinuousEventPriority = enableNewReconciler
+  ? ContinuousEventPriority_new
+  : ContinuousEventPriority_old;
+export const DefaultEventPriority = enableNewReconciler
+  ? DefaultEventPriority_new
+  : DefaultEventPriority_old;
+export const IdleEventPriority = enableNewReconciler
+  ? IdleEventPriority_new
+  : IdleEventPriority_old;

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

@@ -0,0 +1,15 @@
+/**
+ * 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
+ */
+
+export {
+  SyncLanePriority as DiscreteEventPriority,
+  InputContinuousLanePriority as ContinuousEventPriority,
+  DefaultLanePriority as DefaultEventPriority,
+  IdleLanePriority as IdleEventPriority,
+} from './ReactFiberLane.new';

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

@@ -0,0 +1,15 @@
+/**
+ * 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
+ */
+
+export {
+  SyncLanePriority as DiscreteEventPriority,
+  InputContinuousLanePriority as ContinuousEventPriority,
+  DefaultLanePriority as DefaultEventPriority,
+  IdleLanePriority as IdleEventPriority,
+} from './ReactFiberLane.old';

packages/react-reconciler/src/ReactFiberReconciler.js

@@ -52,10 +52,6 @@ import {
   registerMutableSourceForHydration as registerMutableSourceForHydration_old,
   runWithPriority as runWithPriority_old,
   getCurrentUpdateLanePriority as getCurrentUpdateLanePriority_old,
-  DefaultEventPriority as DefaultEventPriority_old,
-  DiscreteEventPriority as DiscreteEventPriority_old,
-  ContinuousEventPriority as ContinuousEventPriority_old,
-  IdleEventPriority as IdleEventPriority_old,
 } from './ReactFiberReconciler.old';
 
 import {
@@ -96,10 +92,6 @@ import {
   registerMutableSourceForHydration as registerMutableSourceForHydration_new,
   runWithPriority as runWithPriority_new,
   getCurrentUpdateLanePriority as getCurrentUpdateLanePriority_new,
-  DefaultEventPriority as DefaultEventPriority_new,
-  DiscreteEventPriority as DiscreteEventPriority_new,
-  ContinuousEventPriority as ContinuousEventPriority_new,
-  IdleEventPriority as IdleEventPriority_new,
 } from './ReactFiberReconciler.new';
 
 export const createContainer = enableNewReconciler
@@ -176,18 +168,6 @@ export const createPortal = enableNewReconciler
 export const createComponentSelector = enableNewReconciler
   ? createComponentSelector_new
   : createComponentSelector_old;
-export const DefaultEventPriority = enableNewReconciler
-  ? DefaultEventPriority_new
-  : DefaultEventPriority_old;
-export const DiscreteEventPriority = enableNewReconciler
-  ? DiscreteEventPriority_new
-  : DiscreteEventPriority_old;
-export const ContinuousEventPriority = enableNewReconciler
-  ? ContinuousEventPriority_new
-  : ContinuousEventPriority_old;
-export const IdleEventPriority = enableNewReconciler
-  ? IdleEventPriority_new
-  : IdleEventPriority_old;
 
 //TODO: "psuedo" is spelled "pseudo"
 export const createHasPseudoClassSelector = enableNewReconciler

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

@@ -8,14 +8,7 @@
  */
 
 import {REACT_OPAQUE_ID_TYPE} from 'shared/ReactSymbols';
-import {enableNewReconciler} from 'shared/ReactFeatureFlags';
-
-import {DefaultLanePriority as DefaultLanePriority_old} from 'react-reconciler/src/ReactFiberLane.old';
-import {DefaultLanePriority as DefaultLanePriority_new} from 'react-reconciler/src/ReactFiberLane.new';
-
-const DefaultLanePriority = enableNewReconciler
-  ? DefaultLanePriority_new
-  : DefaultLanePriority_old;
+import {DefaultEventPriority} from 'react-reconciler/src/ReactEventPriorities';
 
 export type Type = string;
 export type Props = Object;
@@ -223,7 +216,7 @@ export function createTextInstance(
 }
 
 export function getCurrentEventPriority(): * {
-  return DefaultLanePriority;
+  return DefaultEventPriority;
 }
 
 export const isPrimaryRenderer = false;

scripts/rollup/forks.js

@@ -279,6 +279,26 @@ const forks = Object.freeze({
     return 'react-reconciler/src/ReactFiberReconciler.old.js';
   },
 
+  'react-reconciler/src/ReactEventPriorities': (
+    bundleType,
+    entry,
+    dependencies,
+    moduleType,
+    bundle
+  ) => {
+    if (bundle.enableNewReconciler) {
+      switch (bundleType) {
+        case FB_WWW_DEV:
+        case FB_WWW_PROD:
+        case FB_WWW_PROFILING:
+          // Use the forked version of the reconciler
+          return 'react-reconciler/src/ReactEventPriorities.new.js';
+      }
+    }
+    // Otherwise, use the non-forked version.
+    return 'react-reconciler/src/ReactEventPriorities.old.js';
+  },
+
   'react-reconciler/src/ReactFiberHotReloading': (
     bundleType,
     entry,