Avoid importing Scheduler directly

packages/react-art/src/ReactARTHostConfig.js

@@ -5,6 +5,10 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import {
+  unstable_scheduleCallback as scheduleDeferredCallback,
+  unstable_cancelCallback as cancelDeferredCallback,
+} from 'scheduler';
 export {
   unstable_now as now,
   unstable_scheduleCallback as scheduleDeferredCallback,
@@ -337,6 +341,8 @@ export function getChildHostContext() {
 export const scheduleTimeout = setTimeout;
 export const cancelTimeout = clearTimeout;
 export const noTimeout = -1;
+export const schedulePassiveEffects = scheduleDeferredCallback;
+export const cancelPassiveEffects = cancelDeferredCallback;
 
 export function shouldSetTextContent(type, props) {
   return (

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

@@ -69,6 +69,10 @@ export type ChildSet = void; // Unused
 export type TimeoutHandle = TimeoutID;
 export type NoTimeout = -1;
 
+import {
+  unstable_scheduleCallback as scheduleDeferredCallback,
+  unstable_cancelCallback as cancelDeferredCallback,
+} from 'scheduler';
 export {
   unstable_now as now,
   unstable_scheduleCallback as scheduleDeferredCallback,
@@ -296,6 +300,8 @@ export const scheduleTimeout =
 export const cancelTimeout =
   typeof clearTimeout === 'function' ? clearTimeout : (undefined: any);
 export const noTimeout = -1;
+export const schedulePassiveEffects = scheduleDeferredCallback;
+export const cancelPassiveEffects = cancelDeferredCallback;
 
 // -------------------
 //     Mutation

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

@@ -330,6 +330,8 @@ export const shouldYield = ReactNativeFrameSchedulingShouldYield;
 export const scheduleTimeout = setTimeout;
 export const cancelTimeout = clearTimeout;
 export const noTimeout = -1;
+export const schedulePassiveEffects = scheduleDeferredCallback;
+export const cancelPassiveEffects = cancelDeferredCallback;
 
 // -------------------
 //     Persistence

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

@@ -243,6 +243,8 @@ export const shouldYield = ReactNativeFrameSchedulingShouldYield;
 export const scheduleTimeout = setTimeout;
 export const cancelTimeout = clearTimeout;
 export const noTimeout = -1;
+export const schedulePassiveEffects = scheduleDeferredCallback;
+export const cancelPassiveEffects = cancelDeferredCallback;
 
 export function shouldDeprioritizeSubtree(type: string, props: Props): boolean {
   return false;

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

@@ -47,6 +47,7 @@ if (__DEV__) {
 function createReactNoop(reconciler: Function, useMutation: boolean) {
   let scheduledCallback = null;
   let scheduledCallbackTimeout = -1;
+  let scheduledPassiveCallback = null;
   let instanceCounter = 0;
   let hostDiffCounter = 0;
   let hostUpdateCounter = 0;
@@ -338,6 +339,21 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
     scheduleTimeout: setTimeout,
     cancelTimeout: clearTimeout,
     noTimeout: -1,
+    schedulePassiveEffects(callback) {
+      if (scheduledCallback) {
+        throw new Error(
+          'Scheduling a callback twice is excessive. Instead, keep track of ' +
+            'whether the callback has already been scheduled.',
+        );
+      }
+      scheduledPassiveCallback = callback;
+    },
+    cancelPassiveEffects() {
+      if (scheduledPassiveCallback === null) {
+        throw new Error('No passive effects callback is scheduled.');
+      }
+      scheduledPassiveCallback = null;
+    },
 
     prepareForCommit(): void {},
 
@@ -854,6 +870,16 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
       return yieldedValues;
     },
 
+    flushPassiveEffects() {
+      // Trick to flush passive effects without exposing an internal API:
+      // Create a throwaway root and schedule a dummy update on it.
+      const rootID = 'bloopandthenmoreletterstoavoidaconflict';
+      const container = {rootID: rootID, children: []};
+      rootContainers.set(rootID, container);
+      const root = NoopRenderer.createContainer(container, true, false);
+      NoopRenderer.updateContainer(null, root, null, null);
+    },
+
     // Logs the current state of the tree.
     dumpTree(rootID: string = DEFAULT_ROOT_ID) {
       const root = roots.get(rootID);

packages/react-reconciler/src/ReactFiberScheduler.js

@@ -17,10 +17,6 @@ import {
   __subscriberRef,
   unstable_wrap as Schedule_tracing_wrap,
 } from 'scheduler/tracing';
-import {
-  unstable_scheduleCallback as Schedule_scheduleCallback,
-  unstable_cancelCallback as Schedule_cancelCallback,
-} from 'scheduler';
 import {
   invokeGuardedCallback,
   hasCaughtError,
@@ -83,6 +79,8 @@ import {
   scheduleTimeout,
   cancelTimeout,
   noTimeout,
+  schedulePassiveEffects,
+  cancelPassiveEffects,
 } from './ReactFiberHostConfig';
 import {
   markPendingPriorityLevel,
@@ -587,8 +585,10 @@ function markLegacyErrorBoundaryAsFailed(instance: mixed) {
 }
 
 function flushPassiveEffects() {
+  if (passiveEffectCallbackHandle !== null) {
+    cancelPassiveEffects(passiveEffectCallbackHandle);
+  }
   if (passiveEffectCallback !== null) {
-    Schedule_cancelCallback(passiveEffectCallbackHandle);
     // We call the scheduled callback instead of commitPassiveEffects directly
     // to ensure tracing works correctly.
     passiveEffectCallback();
@@ -795,7 +795,7 @@ function commitRoot(root: FiberRoot, finishedWork: Fiber): void {
       // here because that code is still in flux.
       callback = Schedule_tracing_wrap(callback);
     }
-    passiveEffectCallbackHandle = Schedule_scheduleCallback(callback);
+    passiveEffectCallbackHandle = schedulePassiveEffects(callback);
     passiveEffectCallback = callback;
   }