From e37e53086af5c0569830efa607fc42c2b9593be1 Mon Sep 17 00:00:00 2001
From: evanbacon <bacon@expo.io>
Date: Wed, 26 Jul 2023 22:32:54 -0700
Subject: [PATCH 1/2] fix: use import for event-target-shim to support mjs
 (#38628)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Summary:
The React Native community almost exclusively adds `mjs` support with something like: `config.resolver.sourceExts.push("mjs");` which causes `js` to be resolved before `mjs`. Mainstream bundlers will do the opposite, resolving `mjs` then `js`, unless bundling for Node.js environments.

`event-target-shim` has a `.js` and `.mjs` entry, when we [attempt to implement _community-standard_ resolution in Metro](https://github.com/expo/expo/pull/23528) the app fails to open on iOS––providing no indication of what failed. The issue here is that the `mjs` exports for `event-target-shim` don't support `module.exports = function() {}`, so we need to update some of the imports in `react-native` (note that one of the imports to `event-target-shim` already uses `import/export`).

### Discovery

For future readers––to discover this bug, I wrote a custom Metro resolver which printed a list of any `mjs` file that was resolved. In a basic app we observe the following:

```
/node_modules/react-native/Libraries/Core/setUpXHR.js > /node_modules/abort-controller/dist/abort-controller.mjs
/node_modules/react-native/Libraries/Network/XMLHttpRequest.js > /node_modules/event-target-shim/dist/event-target-shim.mjs
/node_modules/react-native/Libraries/WebSocket/WebSocket.js > /node_modules/event-target-shim/dist/event-target-shim.mjs
/node_modules/react-native/Libraries/Blob/FileReader.js > /node_modules/event-target-shim/dist/event-target-shim.mjs
/node_modules/abort-controller/dist/abort-controller.mjs > /node_modules/event-target-shim/dist/event-target-shim.mjs
```

In all cases the mjs files are resolved via `react-native` importing third-party packages, specifically `abort-controller` and `event-target-shim`. I modified the custom Metro resolver to ignore mjs resolution in different files until I found the problematic imports. This revealed that the exports were changing in `event-target-shim` between mjs and js.

Further, this was difficult to discover because the code that attempts to invoke an object as a function (error) is happening during the React Native networking setup. Ideally this JS code would be isolated from the user's bundler configuration and therefore impossible to break.

## Changelog:

[GENERAL] [FIXED] - Update `event-target-shim` import to support Metro resolving `mjs` modules before `js`.

<!-- Help reviewers and the release process by writing your own changelog entry.

Pick one each for the category and type tags:

[ANDROID|GENERAL|IOS|INTERNAL] [BREAKING|ADDED|CHANGED|DEPRECATED|REMOVED|FIXED|SECURITY] - Message

For more details, see:
https://reactnative.dev/contributing/changelogs-in-pull-requests

Pull Request resolved: https://github.com/facebook/react-native/pull/38628

Test Plan:
- If you add `mjs` support to the `metro.config.js` file **before** js (`config.resolver.sourceExts.unshift("mjs");`), the project should be capable of starting.
- Usage with the default `metro.config.js` setup works as well.
- https://github.com/expo/expo/pull/23528 works.

Reviewed By: NickGerleman

Differential Revision: D47816854

Pulled By: TheSavior

fbshipit-source-id: ebaf2e7a3ec02ae61effa004058589053601b766
---
 packages/react-native/Libraries/Blob/FileReader.js        | 3 +--
 packages/react-native/Libraries/Network/XMLHttpRequest.js | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/packages/react-native/Libraries/Blob/FileReader.js b/packages/react-native/Libraries/Blob/FileReader.js
index 3e20afe5c6e1a7..f8154bd237368f 100644
--- a/packages/react-native/Libraries/Blob/FileReader.js
+++ b/packages/react-native/Libraries/Blob/FileReader.js
@@ -12,8 +12,7 @@ import type Blob from './Blob';
 
 import NativeFileReaderModule from './NativeFileReaderModule';
 import {toByteArray} from 'base64-js';
-
-const EventTarget = require('event-target-shim');
+import EventTarget from 'event-target-shim';
 
 type ReadyState =
   | 0 // EMPTY
diff --git a/packages/react-native/Libraries/Network/XMLHttpRequest.js b/packages/react-native/Libraries/Network/XMLHttpRequest.js
index f66d194863a457..e6191b10f7b560 100644
--- a/packages/react-native/Libraries/Network/XMLHttpRequest.js
+++ b/packages/react-native/Libraries/Network/XMLHttpRequest.js
@@ -13,12 +13,12 @@
 import type {IPerformanceLogger} from '../Utilities/createPerformanceLogger';
 
 import {type EventSubscription} from '../vendor/emitter/EventEmitter';
+import EventTarget from 'event-target-shim';
 
 const BlobManager = require('../Blob/BlobManager');
 const GlobalPerformanceLogger = require('../Utilities/GlobalPerformanceLogger');
 const RCTNetworking = require('./RCTNetworking').default;
 const base64 = require('base64-js');
-const EventTarget = require('event-target-shim');
 const invariant = require('invariant');
 
 const DEBUG_NETWORK_SEND_DELAY: false = false; // Set to a number of milliseconds when debugging

From 7e7628d84579a5c9a7a358cb86c5debada4dfdfe Mon Sep 17 00:00:00 2001
From: Nick Gerleman <ngerlem@meta.com>
Date: Wed, 26 Jul 2023 22:43:36 -0700
Subject: [PATCH 2/2] Remove default 50ms Scroll Event Throttling in
 VirtualizedList (#38648)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/38648

This is specific to the scenario, and device, and time-based sampling as implemented on Android may inherently create stutters because we may not proess events at a consistent cadence (and we may never process the last events).

https://github.com/facebook/react-native/pull/38475 made this code no longer no-op on Android, which caused regressions documented in https://github.com/facebook/react-native/issues/38470#issuecomment-1639620459 due to VirtualizedList having more out-of-date information.

We are already coalescing scroll events on both Android and iOS, which will ensure we are not flooded with events. VirtualizedList also already inserts an artificial 50ms delay to new renders by default when high priority work is not happening (see `updateCellsBatchingPeriod`). This limits the heavy work done by VirtualizedList (no new renders or expensive math on scroll events), while letting the list still have the most recent events.

We can eventually remove this once VirtualizedList is able to use OffScreen universally.

Changelog:
[General][Changed] - Remove default 50ms Scroll Event Throttling in VirtualizedList

Differential Revision: D47823772

fbshipit-source-id: 0abf312b9cf5c5f25457b58f4b8cbb393789b14d
---
 .../__snapshots__/FlatList-test.js.snap       |  9 ---
 .../__snapshots__/SectionList-test.js.snap    |  5 --
 .../Lists/VirtualizedList.js                  |  4 --
 .../Lists/VirtualizedListProps.js             |  7 ---
 .../VirtualizedList-test.js.snap              | 57 -------------------
 .../VirtualizedSectionList-test.js.snap       | 12 ----
 6 files changed, 94 deletions(-)

diff --git a/packages/react-native/Libraries/Lists/__tests__/__snapshots__/FlatList-test.js.snap b/packages/react-native/Libraries/Lists/__tests__/__snapshots__/FlatList-test.js.snap
index 86901053a00d9f..b0e9f46bf0fb95 100644
--- a/packages/react-native/Libraries/Lists/__tests__/__snapshots__/FlatList-test.js.snap
+++ b/packages/react-native/Libraries/Lists/__tests__/__snapshots__/FlatList-test.js.snap
@@ -28,7 +28,6 @@ exports[`FlatList ignores invalid data 1`] = `
   pagingEnabled={false}
   removeClippedSubviews={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   scrollViewRef={[Function]}
   sendMomentumEvents={true}
   snapToEnd={true}
@@ -104,7 +103,6 @@ exports[`FlatList renders all the bells and whistles 1`] = `
   refreshing={false}
   removeClippedSubviews={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   viewabilityConfigCallbackPairs={Array []}
 >
@@ -222,7 +220,6 @@ exports[`FlatList renders array-like data 1`] = `
   pagingEnabled={false}
   removeClippedSubviews={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   scrollViewRef={[Function]}
   sendMomentumEvents={true}
   snapToEnd={true}
@@ -295,7 +292,6 @@ exports[`FlatList renders empty list 1`] = `
   onScrollEndDrag={[Function]}
   removeClippedSubviews={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   viewabilityConfigCallbackPairs={Array []}
 >
@@ -317,7 +313,6 @@ exports[`FlatList renders null list 1`] = `
   onScrollEndDrag={[Function]}
   removeClippedSubviews={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   viewabilityConfigCallbackPairs={Array []}
 >
@@ -352,7 +347,6 @@ exports[`FlatList renders simple list (multiple columns) 1`] = `
   onScrollEndDrag={[Function]}
   removeClippedSubviews={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   viewabilityConfigCallbackPairs={Array []}
 >
@@ -425,7 +419,6 @@ exports[`FlatList renders simple list 1`] = `
   onScrollEndDrag={[Function]}
   removeClippedSubviews={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   viewabilityConfigCallbackPairs={Array []}
 >
@@ -488,7 +481,6 @@ exports[`FlatList renders simple list using ListItemComponent (multiple columns)
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   removeClippedSubviews={false}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   viewabilityConfigCallbackPairs={Array []}
 >
@@ -561,7 +553,6 @@ exports[`FlatList renders simple list using ListItemComponent 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   removeClippedSubviews={false}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   viewabilityConfigCallbackPairs={Array []}
 >
diff --git a/packages/react-native/Libraries/Lists/__tests__/__snapshots__/SectionList-test.js.snap b/packages/react-native/Libraries/Lists/__tests__/__snapshots__/SectionList-test.js.snap
index a700cdb7be2a73..d07a5a944248f7 100644
--- a/packages/react-native/Libraries/Lists/__tests__/__snapshots__/SectionList-test.js.snap
+++ b/packages/react-native/Libraries/Lists/__tests__/__snapshots__/SectionList-test.js.snap
@@ -28,7 +28,6 @@ exports[`SectionList rendering empty section headers is fine 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -89,7 +88,6 @@ exports[`SectionList renders a footer when there is no data 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -140,7 +138,6 @@ exports[`SectionList renders a footer when there is no data and no header 1`] =
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -231,7 +228,6 @@ exports[`SectionList renders all the bells and whistles 1`] = `
   }
   refreshing={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       1,
@@ -422,7 +418,6 @@ exports[`SectionList renders empty list 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View />
diff --git a/packages/virtualized-lists/Lists/VirtualizedList.js b/packages/virtualized-lists/Lists/VirtualizedList.js
index 50dad2f2dab389..eaa5ba70460687 100644
--- a/packages/virtualized-lists/Lists/VirtualizedList.js
+++ b/packages/virtualized-lists/Lists/VirtualizedList.js
@@ -60,7 +60,6 @@ import {
   maxToRenderPerBatchOrDefault,
   onStartReachedThresholdOrDefault,
   onEndReachedThresholdOrDefault,
-  scrollEventThrottleOrDefault,
   windowSizeOrDefault,
 } from './VirtualizedListProps';
 
@@ -1094,9 +1093,6 @@ class VirtualizedList extends StateSafePureComponent<Props, State> {
       onScrollEndDrag: this._onScrollEndDrag,
       onMomentumScrollBegin: this._onMomentumScrollBegin,
       onMomentumScrollEnd: this._onMomentumScrollEnd,
-      scrollEventThrottle: scrollEventThrottleOrDefault(
-        this.props.scrollEventThrottle,
-      ), // TODO: Android support
       invertStickyHeaders:
         this.props.invertStickyHeaders !== undefined
           ? this.props.invertStickyHeaders
diff --git a/packages/virtualized-lists/Lists/VirtualizedListProps.js b/packages/virtualized-lists/Lists/VirtualizedListProps.js
index 2d670673c11ba9..5d8b0cd0bb4bc3 100644
--- a/packages/virtualized-lists/Lists/VirtualizedListProps.js
+++ b/packages/virtualized-lists/Lists/VirtualizedListProps.js
@@ -331,13 +331,6 @@ export function onEndReachedThresholdOrDefault(
   return onEndReachedThreshold ?? 2;
 }
 
-// scrollEventThrottleOrDefault(this.props.scrollEventThrottle)
-export function scrollEventThrottleOrDefault(
-  scrollEventThrottle: ?number,
-): number {
-  return scrollEventThrottle ?? 50;
-}
-
 // windowSizeOrDefault(this.props.windowSize)
 export function windowSizeOrDefault(windowSize: ?number): number {
   return windowSize ?? 21;
diff --git a/packages/virtualized-lists/Lists/__tests__/__snapshots__/VirtualizedList-test.js.snap b/packages/virtualized-lists/Lists/__tests__/__snapshots__/VirtualizedList-test.js.snap
index b877e3da84d999..89b38306942e96 100644
--- a/packages/virtualized-lists/Lists/__tests__/__snapshots__/VirtualizedList-test.js.snap
+++ b/packages/virtualized-lists/Lists/__tests__/__snapshots__/VirtualizedList-test.js.snap
@@ -53,7 +53,6 @@ exports[`VirtualizedList forwards correct stickyHeaderIndices when ListHeaderCom
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -210,7 +209,6 @@ exports[`VirtualizedList forwards correct stickyHeaderIndices when all in initia
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -361,7 +359,6 @@ exports[`VirtualizedList forwards correct stickyHeaderIndices when partially in
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -445,7 +442,6 @@ exports[`VirtualizedList handles nested lists 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -476,7 +472,6 @@ exports[`VirtualizedList handles nested lists 1`] = `
         onScrollBeginDrag={[Function]}
         onScrollEndDrag={[Function]}
         renderItem={[Function]}
-        scrollEventThrottle={50}
         stickyHeaderIndices={Array []}
       >
         <View
@@ -526,7 +521,6 @@ exports[`VirtualizedList handles nested lists 1`] = `
         onScrollBeginDrag={[Function]}
         onScrollEndDrag={[Function]}
         renderItem={[Function]}
-        scrollEventThrottle={50}
         stickyHeaderIndices={Array []}
       >
         <View>
@@ -595,7 +589,6 @@ exports[`VirtualizedList handles separators correctly 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -672,7 +665,6 @@ exports[`VirtualizedList handles separators correctly 2`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -749,7 +741,6 @@ exports[`VirtualizedList handles separators correctly 3`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -886,7 +877,6 @@ exports[`VirtualizedList keeps sticky headers above viewport visualized 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -1031,7 +1021,6 @@ exports[`VirtualizedList renders all the bells and whistles 1`] = `
   }
   refreshing={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   style={
     Array [
@@ -1203,7 +1192,6 @@ exports[`VirtualizedList renders empty list 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View />
@@ -1223,7 +1211,6 @@ exports[`VirtualizedList renders empty list after batch 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View />
@@ -1246,7 +1233,6 @@ exports[`VirtualizedList renders empty list with empty component 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -1286,7 +1272,6 @@ exports[`VirtualizedList renders list with empty component 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -1315,7 +1300,6 @@ exports[`VirtualizedList renders null list 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View />
@@ -1347,7 +1331,6 @@ exports[`VirtualizedList renders simple list 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -1407,7 +1390,6 @@ exports[`VirtualizedList renders simple list using ListItemComponent 1`] = `
   onScroll={[Function]}
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -1494,7 +1476,6 @@ exports[`VirtualizedList renders sticky headers in viewport on batched render 1`
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -1576,7 +1557,6 @@ exports[`VirtualizedList test getItem functionality where data is not an Array 1
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -1613,7 +1593,6 @@ exports[`VirtualizedList warns if both renderItem or ListItemComponent are speci
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -1711,7 +1690,6 @@ exports[`adjusts render area with non-zero initialScrollIndex 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={10}
 >
@@ -1911,7 +1889,6 @@ exports[`clamps render area when items removed for initialScrollIndex > 0 and sc
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={10}
 >
@@ -2049,7 +2026,6 @@ exports[`constrains batch render region when an item is removed 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -2176,7 +2152,6 @@ exports[`discards intitial render if initialScrollIndex != 0 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -2318,7 +2293,6 @@ exports[`does not adjust render area until content area layed out 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={10}
 >
@@ -2453,7 +2427,6 @@ exports[`does not move render area when initialScrollIndex is > 0 and offset not
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={10}
 >
@@ -2565,7 +2538,6 @@ exports[`does not over-render when there is less than initialNumToRender cells 1
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -2679,7 +2651,6 @@ exports[`eventually renders all items when virtualization disabled 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -2818,7 +2789,6 @@ exports[`expands first in viewport to render up to maxToRenderPerBatch on initia
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -2935,7 +2905,6 @@ exports[`expands render area by maxToRenderPerBatch on tick 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -3055,7 +3024,6 @@ exports[`gracefully handles negative initialScrollIndex 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -3226,7 +3194,6 @@ exports[`handles maintainVisibleContentPosition 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -3395,7 +3362,6 @@ exports[`handles maintainVisibleContentPosition 2`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -3579,7 +3545,6 @@ exports[`handles maintainVisibleContentPosition 3`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -3706,7 +3671,6 @@ exports[`initially renders nothing when initialNumToRender is 0 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -3799,7 +3763,6 @@ exports[`keeps viewport above last focused rendered 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -3997,7 +3960,6 @@ exports[`keeps viewport below last focused rendered 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -4180,7 +4142,6 @@ exports[`renders a zero-height tail spacer on initial render if getItemLayout no
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -4270,7 +4231,6 @@ exports[`renders full tail spacer if all cells measured 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -4381,7 +4341,6 @@ exports[`renders initialNumToRender cells when virtualization disabled 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -4480,7 +4439,6 @@ exports[`renders items before initialScrollIndex on first batch tick when virtua
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -4576,7 +4534,6 @@ exports[`renders new items when data is updated with non-zero initialScrollIndex
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={10}
 >
@@ -4659,7 +4616,6 @@ exports[`renders no spacers up to initialScrollIndex on first render when virtua
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -4732,7 +4688,6 @@ exports[`renders offset cells in initial render when initialScrollIndex set 1`]
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -4834,7 +4789,6 @@ exports[`renders tail spacer up to last measured index if getItemLayout not defi
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -4943,7 +4897,6 @@ exports[`renders tail spacer up to last measured with irregular layout when getI
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -5044,7 +4997,6 @@ exports[`renders windowSize derived region at bottom 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={3}
 >
@@ -5157,7 +5109,6 @@ exports[`renders windowSize derived region at top 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={3}
 >
@@ -5254,7 +5205,6 @@ exports[`renders windowSize derived region in middle 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={3}
 >
@@ -5389,7 +5339,6 @@ exports[`renders zero-height tail spacer on batch render if cells not yet measur
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -5484,7 +5433,6 @@ exports[`retains batch render region when an item is appended 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -5630,7 +5578,6 @@ exports[`retains initial render region when an item is appended 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -5748,7 +5695,6 @@ exports[`retains intitial render if initialScrollIndex == 0 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -5937,7 +5883,6 @@ exports[`unmounts sticky headers moved below viewport 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={
     Array [
       0,
@@ -6075,7 +6020,6 @@ exports[`virtualizes away last focused index if item removed 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
@@ -6265,7 +6209,6 @@ exports[`virtualizes away last focused item if focus changes to a new cell 1`] =
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   windowSize={1}
 >
diff --git a/packages/virtualized-lists/Lists/__tests__/__snapshots__/VirtualizedSectionList-test.js.snap b/packages/virtualized-lists/Lists/__tests__/__snapshots__/VirtualizedSectionList-test.js.snap
index 3f64c8856611e6..85a710f1ef4787 100644
--- a/packages/virtualized-lists/Lists/__tests__/__snapshots__/VirtualizedSectionList-test.js.snap
+++ b/packages/virtualized-lists/Lists/__tests__/__snapshots__/VirtualizedSectionList-test.js.snap
@@ -28,7 +28,6 @@ exports[`VirtualizedSectionList handles nested lists 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -70,7 +69,6 @@ exports[`VirtualizedSectionList handles nested lists 1`] = `
         onScrollBeginDrag={[Function]}
         onScrollEndDrag={[Function]}
         renderItem={[Function]}
-        scrollEventThrottle={50}
         stickyHeaderIndices={Array []}
       >
         <View
@@ -136,7 +134,6 @@ exports[`VirtualizedSectionList handles nested lists 1`] = `
         onScrollBeginDrag={[Function]}
         onScrollEndDrag={[Function]}
         renderItem={[Function]}
-        scrollEventThrottle={50}
         stickyHeaderIndices={Array []}
       >
         <View>
@@ -239,7 +236,6 @@ exports[`VirtualizedSectionList handles separators correctly 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -377,7 +373,6 @@ exports[`VirtualizedSectionList handles separators correctly 2`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -515,7 +510,6 @@ exports[`VirtualizedSectionList handles separators correctly 3`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -654,7 +648,6 @@ exports[`VirtualizedSectionList handles separators correctly 4`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -813,7 +806,6 @@ exports[`VirtualizedSectionList renders all the bells and whistles 1`] = `
   }
   refreshing={false}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
   style={
     Array [
@@ -1028,7 +1020,6 @@ exports[`VirtualizedSectionList renders empty list 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View />
@@ -1052,7 +1043,6 @@ exports[`VirtualizedSectionList renders empty list with empty component 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -1098,7 +1088,6 @@ exports[`VirtualizedSectionList renders list with empty component 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>
@@ -1156,7 +1145,6 @@ exports[`VirtualizedSectionList renders simple list 1`] = `
   onScrollBeginDrag={[Function]}
   onScrollEndDrag={[Function]}
   renderItem={[Function]}
-  scrollEventThrottle={50}
   stickyHeaderIndices={Array []}
 >
   <View>