Fix TS exactOptionalPropertyTypes compatibility for generated types (#57628) (#57699)

Summary:
Pull Request resolved: https://github.com/react/react-native/pull/57628

NOTE: Patches over a `flow-api-translator` bug, which I'll fix upstream later. We need to pick this to `0.87-stable` to resolve user integration issues.

**Context**

TypeScript's `exactOptionalPropertyTypes` flag (strict mode) creates a distinction between `foo?: T` and `foo?: T | undefined`.

```js
// Flow's semantics

interface Props {
  onRefresh?: () => void;
}
const a: Props = { onRefresh: undefined }; // ✅ ok
```
```ts
// TypeScript with exactOptionalPropertyTypes: true (i.e. strict mode)

interface Props {
  onRefresh?: () => void;
}
const a: Props = { onRefresh: undefined }; // ❌ error

interface PropsFixed {
  onRefresh?: (() => void) | undefined;
}
const b: PropsFixed = { onRefresh: undefined }; // ✅ ok
```

With this added strictness in TypeScript, our generated types via `flow-api-translator` could create downstream type incompatibility in apps.

**This diff**

Patches the above issue in React Native's Flow → TS `types_generated/` pipeline. We transform all instances to the wider `foo?: T | undefined` format, for maximum compatibility.

**Notes**

`foo?: T [| undefined]` **remains stripped** in the API snapshot (existing transform with the aim of a concise format). There is a net, nonfunctional snapshot diff around function members, which (as a positive result) are re-ordered.

Changelog:
[General][Fixed] - **Strict TypeScript API**: Optional property types are now widened to explicitly include `| undefined` for `exactOptionalPropertyTypes` compatibility

Reviewed By: cipolleschi

Differential Revision: D113030161

fbshipit-source-id: 3ab005edab6b80b18fbb9ae7125ba56e3bd94195

Co-authored-by: Alex Hunt <huntie@meta.com>

packages/react-native/ReactNativeApi.d.ts

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<883e9c745f0864d256fd0a4760f97b1c>>
+ * @generated SignedSource<<955e3ecbb2aa295ace2e98ea3a2d3018>>
  *
  * This file was generated by scripts/js-api/build-types/index.js.
  */
@@ -1711,10 +1711,10 @@ declare interface ButtonProps {
   readonly nextFocusRight?: number
   readonly nextFocusUp?: number
   readonly onAccessibilityAction?: (event: AccessibilityActionEvent) => unknown
+  readonly onPress?: (event?: GestureResponderEvent) => unknown
   readonly testID?: string
   readonly title: string
   readonly touchSoundDisabled?: boolean
-  readonly onPress?: (event?: GestureResponderEvent) => unknown
 }
 declare function cancelHeadlessTask(taskId: number, taskKey: string): void
 declare type Category = string
@@ -1741,9 +1741,9 @@ declare type CellRendererProps<ItemT> = {
   readonly children: React.ReactNode
   readonly index: number
   readonly item: ItemT
-  readonly style: StyleProp<ViewStyle>
   readonly onFocusCapture?: (event: FocusEvent) => void
   readonly onLayout?: (event: LayoutChangeEvent) => void
+  readonly style: StyleProp<ViewStyle>
 }
 declare class CellRenderMask {
   addCells(cells: { first: number; last: number }): void
@@ -2683,12 +2683,12 @@ declare type InterpolationConfigType<
   OutputT extends InterpolationConfigSupportedOutputType,
 > = Readonly<
   AnimatedNodeConfig & {
+    easing?: (input: number) => number
     extrapolate?: ExtrapolateType
     extrapolateLeft?: ExtrapolateType
     extrapolateRight?: ExtrapolateType
     inputRange: ReadonlyArray<number>
     outputRange: ReadonlyArray<OutputT>
-    easing?: (input: number) => number
   }
 >
 declare type IOSKeyboardEvent = Readonly<
@@ -3350,6 +3350,14 @@ declare type OptionalFlatListProps<ItemT> = {
         end: number
         start: number
       }
+  getItemLayout?: (
+    data: Readonly<ArrayLike<ItemT>> | undefined,
+    index: number,
+  ) => {
+    index: number
+    length: number
+    offset: number
+  }
   horizontal?: boolean
   initialNumToRender?: number
   initialScrollIndex?: number
@@ -3359,14 +3367,6 @@ declare type OptionalFlatListProps<ItemT> = {
   removeClippedSubviews?: boolean
   renderItem?: ListRenderItem<ItemT>
   strictMode?: boolean
-  getItemLayout?: (
-    data: Readonly<ArrayLike<ItemT>> | undefined,
-    index: number,
-  ) => {
-    index: number
-    length: number
-    offset: number
-  }
 }
 declare type OptionalPlatformSelectSpec<T> = { [key in PlatformOSType]?: T }
 declare type OptionalSectionListProps<ItemT, SectionT = DefaultSectionT> = {
@@ -3383,6 +3383,14 @@ declare type OptionalVirtualizedListProps = {
   debug?: boolean
   disableVirtualization?: boolean
   extraData?: any
+  getItemLayout?: (
+    data: any,
+    index: number,
+  ) => {
+    index: number
+    length: number
+    offset: number
+  }
   horizontal?: boolean
   initialNumToRender?: number
   initialScrollIndex?: number
@@ -3416,29 +3424,17 @@ declare type OptionalVirtualizedListProps = {
   refreshing?: boolean
   removeClippedSubviews?: boolean
   renderItem?: ListRenderItem<Item>
+  renderScrollComponent?: (props: ScrollViewProps) => React.JSX.Element
   updateCellsBatchingPeriod?: number
   viewabilityConfig?: ViewabilityConfig
   viewabilityConfigCallbackPairs?: Array<ViewabilityConfigCallbackPair>
   windowSize?: number
-  getItemLayout?: (
-    data: any,
-    index: number,
-  ) => {
-    index: number
-    length: number
-    offset: number
-  }
-  renderScrollComponent?: (props: ScrollViewProps) => React.JSX.Element
 }
 declare type OptionalVirtualizedSectionListProps<
   ItemT,
   SectionT = DefaultVirtualizedSectionT,
 > = {
   onEndReached?: ($$PARAM_0$$: { distanceFromEnd: number }) => void
-  renderSectionFooter?: (info: { section: SectionT }) => null | React.ReactNode
-  renderSectionHeader?: (info: { section: SectionT }) => null | React.ReactNode
-  SectionSeparatorComponent?: React.ComponentType<any>
-  stickySectionHeadersEnabled?: boolean
   renderItem?: (info: {
     index: number
     item: ItemT
@@ -3449,6 +3445,10 @@ declare type OptionalVirtualizedSectionListProps<
       updateProps: (select: "leading" | "trailing", newProps: Object) => void
     }
   }) => null | React.ReactNode
+  renderSectionFooter?: (info: { section: SectionT }) => null | React.ReactNode
+  renderSectionHeader?: (info: { section: SectionT }) => null | React.ReactNode
+  SectionSeparatorComponent?: React.ComponentType<any>
+  stickySectionHeadersEnabled?: boolean
 }
 declare type OrientationChangeEvent = {
   readonly orientation: "landscape" | "portrait"
@@ -3687,13 +3687,13 @@ declare type PressabilityConfig = {
   readonly pressRectOffset?: RectOrSize
 }
 declare type PressabilityEventHandlers = {
-  readonly onBlur: (event: BlurEvent) => void
-  readonly onClick: (event: GestureResponderEvent) => void
-  readonly onFocus: (event: FocusEvent) => void
   readonly onMouseEnter?: (event: MouseEvent) => void
   readonly onMouseLeave?: (event: MouseEvent) => void
   readonly onPointerEnter?: (event: PointerEvent) => void
   readonly onPointerLeave?: (event: PointerEvent) => void
+  readonly onBlur: (event: BlurEvent) => void
+  readonly onClick: (event: GestureResponderEvent) => void
+  readonly onFocus: (event: FocusEvent) => void
   readonly onResponderGrant: (event: GestureResponderEvent) => boolean | void
   readonly onResponderMove: (event: GestureResponderEvent) => void
   readonly onResponderRelease: (event: GestureResponderEvent) => void
@@ -4353,6 +4353,14 @@ declare type ScrollViewBaseProps = {
     readonly autoscrollToTopThreshold?: number
     readonly minIndexForVisible: number
   }
+  readonly onContentSizeChange?: (
+    contentWidth: number,
+    contentHeight: number,
+  ) => void
+  readonly onKeyboardDidHide?: (event: KeyboardEvent) => void
+  readonly onKeyboardDidShow?: (event: KeyboardEvent) => void
+  readonly onKeyboardWillHide?: (event: KeyboardEvent) => void
+  readonly onKeyboardWillShow?: (event: KeyboardEvent) => void
   readonly onMomentumScrollBegin?: (event: ScrollEvent) => void
   readonly onMomentumScrollEnd?: (event: ScrollEvent) => void
   readonly onScroll?: (event: ScrollEvent) => void
@@ -4373,14 +4381,6 @@ declare type ScrollViewBaseProps = {
   readonly StickyHeaderComponent?: StickyHeaderComponentType
   readonly stickyHeaderHiddenOnScroll?: boolean
   readonly stickyHeaderIndices?: ReadonlyArray<number>
-  readonly onContentSizeChange?: (
-    contentWidth: number,
-    contentHeight: number,
-  ) => void
-  readonly onKeyboardDidHide?: (event: KeyboardEvent) => void
-  readonly onKeyboardDidShow?: (event: KeyboardEvent) => void
-  readonly onKeyboardWillHide?: (event: KeyboardEvent) => void
-  readonly onKeyboardWillShow?: (event: KeyboardEvent) => void
 }
 declare type ScrollViewComponentStatics = {
   readonly Context: typeof $$ScrollViewContext
@@ -4461,13 +4461,13 @@ declare type ScrollViewPropsIOS = {
   readonly indicatorStyle?: "black" | "default" | "white"
   readonly maximumZoomScale?: number
   readonly minimumZoomScale?: number
+  readonly onScrollToTop?: (event: ScrollEvent) => void
   readonly pinchGestureEnabled?: boolean
   readonly scrollIndicatorInsets?: EdgeInsetsProp
   readonly scrollsToTop?: boolean
   readonly scrollToOverflowEnabled?: boolean
   readonly showsHorizontalScrollIndicator?: boolean
   readonly zoomScale?: number
-  readonly onScrollToTop?: (event: ScrollEvent) => void
 }
 declare interface ScrollViewScrollToOptions {
   animated?: boolean
@@ -4491,6 +4491,10 @@ declare type SectionBase<
   data: ReadonlyArray<SectionItemT>
   ItemSeparatorComponent?: React.ComponentType<any> | React.JSX.Element
   key?: string
+  keyExtractor?: (
+    item: SectionItemT | undefined,
+    index?: number | undefined,
+  ) => string
   renderItem?: (info: {
     index: number
     item: SectionItemT
@@ -4501,10 +4505,6 @@ declare type SectionBase<
       updateProps: (select: "leading" | "trailing", newProps: Object) => void
     }
   }) => null | React.JSX.Element
-  keyExtractor?: (
-    item: SectionItemT | undefined,
-    index?: number | undefined,
-  ) => string
 }
 declare class SectionList<
   ItemT = any,
@@ -4634,6 +4634,17 @@ declare type ShareOptions = {
 }
 declare interface Spec extends TurboModule {
   readonly blur?: (reactTag: number) => void
+  readonly focus?: (reactTag: number) => void
+  readonly getConstantsForViewManager?: (
+    viewManagerName: string,
+  ) => Object | undefined
+  readonly getDefaultEventTypes?: () => Array<string>
+  readonly lazilyLoadView?: (name: string) => Object
+  readonly sendAccessibilityEvent?: (
+    reactTag: number,
+    eventType: number,
+  ) => void
+  readonly setLayoutAnimationEnabledExperimental?: (enabled: boolean) => void
   readonly clearJSResponder: () => void
   readonly configureNextLayoutAnimation: (
     config: Object,
@@ -4662,13 +4673,7 @@ declare interface Spec extends TurboModule {
       height: number,
     ) => void,
   ) => void
-  readonly focus?: (reactTag: number) => void
   readonly getConstants: () => Object
-  readonly getConstantsForViewManager?: (
-    viewManagerName: string,
-  ) => Object | undefined
-  readonly getDefaultEventTypes?: () => Array<string>
-  readonly lazilyLoadView?: (name: string) => Object
   readonly manageChildren: (
     containerTag: number,
     moveFromIndices: Array<number>,
@@ -4701,16 +4706,11 @@ declare interface Spec extends TurboModule {
       height: number,
     ) => void,
   ) => void
-  readonly sendAccessibilityEvent?: (
-    reactTag: number,
-    eventType: number,
-  ) => void
   readonly setChildren: (containerTag: number, reactTags: Array<number>) => void
   readonly setJSResponder: (
     reactTag: number,
     blockNativeResponder: boolean,
   ) => void
-  readonly setLayoutAnimationEnabledExperimental?: (enabled: boolean) => void
   readonly updateView: (
     reactTag: number,
     viewName: string,
@@ -5318,6 +5318,7 @@ declare type TimingAnimationConfig = Readonly<
   AnimationConfig & {
     delay?: number
     duration?: number
+    easing?: (value: number) => number
     toValue:
       | AnimatedColor_default
       | AnimatedInterpolation_default<number>
@@ -5329,7 +5330,6 @@ declare type TimingAnimationConfig = Readonly<
           readonly x: number
           readonly y: number
         }
-    easing?: (value: number) => number
   }
 >
 declare type ToastAndroid = typeof ToastAndroid
@@ -5859,22 +5859,22 @@ export {
   AccessibilityActionEvent, // a0d4daa0
   AccessibilityActionInfo, // db47a917
   AccessibilityInfo, // 23a3aa9b
-  AccessibilityProps, // 21f32d3a
+  AccessibilityProps, // eda80653
   AccessibilityRole, // f2f2e066
   AccessibilityState, // b0c2b3f7
   AccessibilityValue, // cf8bcb74
   ActionSheetIOS, // b558559e
   ActionSheetIOSOptions, // 1756eb5a
-  ActivityIndicator, // 0f796809
+  ActivityIndicator, // e43c68bb
   ActivityIndicatorInstance, // a82dd4e7
-  ActivityIndicatorProps, // a232e3ff
-  Alert, // 5bf12165
+  ActivityIndicatorProps, // 619842eb
+  Alert, // a398a509
   AlertButton, // bf1a3b60
   AlertButtonStyle, // ec9fb242
-  AlertOptions, // a0cdac0f
+  AlertOptions, // 8a116d2a
   AlertType, // 5ab91217
   AndroidKeyboardEvent, // e03becc8
-  Animated, // 91a7b171
+  Animated, // 50cbe576
   AppConfig, // 35c0ca70
   AppRegistry, // 1e8c5a00
   AppState, // 12012be5
@@ -5888,9 +5888,9 @@ export {
   BackPressEventName, // 4620fb76
   BlurEvent, // 4ba4f941
   BoxShadowValue, // b679703f
-  Button, // 2e36a068
-  ButtonInstance, // 0a11787b
-  ButtonProps, // 4a8a20e3
+  Button, // bc8f6464
+  ButtonInstance, // d94b4241
+  ButtonProps, // 21c5780c
   Clipboard, // 41addb89
   CodegenTypes, // ab4986cc
   ColorSchemeName, // 6615edd6
@@ -5908,9 +5908,9 @@ export {
   DimensionsPayload, // 653bc26c
   DisplayMetrics, // 1dc35cef
   DisplayMetricsAndroid, // 872e62eb
-  DrawerLayoutAndroid, // a8ced056
+  DrawerLayoutAndroid, // 7843b7b5
   DrawerLayoutAndroidInstance, // c0694352
-  DrawerLayoutAndroidProps, // e9a67dd7
+  DrawerLayoutAndroidProps, // 0c1d6155
   DrawerSlideEvent, // c4ab8fba
   DropShadowValue, // e9df2606
   DynamicColorIOS, // d96c228c
@@ -5926,39 +5926,39 @@ export {
   EventSubscription, // b8d084aa
   ExtendedExceptionData, // 5a6ccf5a
   FilterFunction, // bf24c0e3
-  FlatList, // 0f2531c9
-  FlatListInstance, // f31d4744
-  FlatListProps, // b8b5adf2
+  FlatList, // e1b005c7
+  FlatListInstance, // 2d1d8e45
+  FlatListProps, // 94fa2dc7
   FocusEvent, // 850f1517
   FontVariant, // 7c7558bb
   GestureResponderEvent, // 14d3e77a
-  GestureResponderHandlers, // c976c2ea
+  GestureResponderHandlers, // b540de80
   HostComponent, // a611806a
   HostInstance, // f78dcaf8
   I18nManager, // f9870e00
   IEventEmitter, // fbef6131
   IOSKeyboardEvent, // e67bfe3a
   IgnorePattern, // ec6f6ece
-  Image, // fba54a35
-  ImageBackground, // 1543bae2
-  ImageBackgroundInstance, // 610d9eed
-  ImageBackgroundProps, // ceb153c3
+  Image, // 87b793a4
+  ImageBackground, // abfd6c1d
+  ImageBackgroundInstance, // 50bc4cb3
+  ImageBackgroundProps, // e04f173a
   ImageErrorEvent, // 978933f4
   ImageInstance, // 9a100753
   ImageLoadEvent, // 77f0b718
   ImageProgressEventIOS, // 445331a4
-  ImageProps, // e8aecf89
-  ImagePropsAndroid, // 9fd9bcbb
-  ImagePropsBase, // f5535cef
-  ImagePropsIOS, // 4a080668
+  ImageProps, // c50cfe0d
+  ImagePropsAndroid, // ee00e1d5
+  ImagePropsBase, // fa3f8e21
+  ImagePropsIOS, // 9e19c85d
   ImageRequireSource, // 681d683b
   ImageResizeMode, // d51106e2
   ImageResolvedAssetSource, // f3060931
   ImageSize, // 1c47cf88
-  ImageSource, // 48c7f316
-  ImageSourcePropType, // bfb5e5c6
+  ImageSource, // ea31cf4a
+  ImageSourcePropType, // f522e093
   ImageStyle, // 4b7c1906
-  ImageURISource, // 016eb083
+  ImageURISource, // 443d047c
   InputAccessoryView, // 9695d393
   InputAccessoryViewProps, // d94dc290
   InputModeOptions, // 4e8581b9
@@ -5967,9 +5967,9 @@ export {
   KeyEvent, // 20fa4267
   KeyUpEvent, // 57f832c5
   Keyboard, // 49414c97
-  KeyboardAvoidingView, // cf0307d2
-  KeyboardAvoidingViewInstance, // c4ca43a7
-  KeyboardAvoidingViewProps, // cf148633
+  KeyboardAvoidingView, // fbf69b90
+  KeyboardAvoidingViewInstance, // f6c63fc9
+  KeyboardAvoidingViewProps, // 8609524c
   KeyboardEvent, // c3f895d4
   KeyboardEventEasing, // af4091c8
   KeyboardEventName, // 59299ad6
@@ -5994,12 +5994,12 @@ export {
   MeasureInWindowOnSuccessCallback, // a285f598
   MeasureLayoutOnSuccessCallback, // 3592502a
   MeasureOnSuccessCallback, // 82824e59
-  Modal, // 43f50013
-  ModalBaseProps, // ac3931ad
+  Modal, // 252d448a
+  ModalBaseProps, // c294cc46
   ModalInstance, // d466ce77
-  ModalProps, // 35252d68
+  ModalProps, // 757e7cec
   ModalPropsAndroid, // 515fb173
-  ModalPropsIOS, // 0e13cfcc
+  ModalPropsIOS, // 664ecb7e
   ModeChangeEvent, // f64bf69d
   MouseEvent, // d1f889fd
   NativeAppEventEmitter, // 08d4c47d
@@ -6017,10 +6017,10 @@ export {
   Networking, // bbc5be42
   OpaqueColorValue, // 25f3fa5b
   PackagerAsset, // d1c88cf4
-  PanResponder, // f8f71cac
-  PanResponderCallbacks, // 6d63e7be
+  PanResponder, // e4df325a
+  PanResponderCallbacks, // c3dafe87
   PanResponderGestureState, // 54baf558
-  PanResponderInstance, // 69cebbe8
+  PanResponderInstance, // 8ccc05bf
   Permission, // 08f1c82f
   PermissionStatus, // 4b7de97b
   PermissionsAndroid, // 8a0bc8d8
@@ -6031,17 +6031,17 @@ export {
   PlatformSelectSpec, // 09ed7758
   PointValue, // 69db075f
   PointerEvent, // ff599afe
-  PressabilityConfig, // faab5639
-  PressabilityEventHandlers, // 0b910091
-  Pressable, // f4911021
+  PressabilityConfig, // fea539a5
+  PressabilityEventHandlers, // c222648b
+  Pressable, // 7008c06f
   PressableAndroidRippleConfig, // ee32eaca
   PressableInstance, // eebfe911
-  PressableProps, // 95d57db2
+  PressableProps, // d6bfa55b
   PressableStateCallbackType, // 9af36561
   ProcessedColorValue, // 33f74304
-  ProgressBarAndroid, // 44a46d48
+  ProgressBarAndroid, // 7b9eaaf0
   ProgressBarAndroidInstance, // ab545ef1
-  ProgressBarAndroidProps, // f20ebde5
+  ProgressBarAndroidProps, // 07fa83a1
   PublicRootInstance, // 8040afd7
   PublicTextInstance, // 6937c7bf
   PushNotificationEventName, // 84e7e150
@@ -6049,10 +6049,10 @@ export {
   PushNotificationPermissions, // c2e7ae4f
   Rationale, // 5df1b1c1
   ReactNativeVersion, // abd76827
-  RefreshControl, // 5b3465d2
-  RefreshControlInstance, // 8b4d078b
-  RefreshControlProps, // f8883f9a
-  RefreshControlPropsAndroid, // 99f64c97
+  RefreshControl, // 947cb880
+  RefreshControlInstance, // 55f1814a
+  RefreshControlProps, // eb2b1cbe
+  RefreshControlPropsAndroid, // 8ac931ca
   RefreshControlPropsIOS, // 72a36381
   Registry, // 6c39216d
   ResponderSyntheticEvent, // ebfa7f48
@@ -6063,26 +6063,26 @@ export {
   RootViewStyleProvider, // 8792d506
   Runnable, // 594dd93a
   Runnables, // 4367c557
-  SafeAreaView, // 47b1ede1
+  SafeAreaView, // 9ce03f75
   SafeAreaViewInstance, // 21dba39c
   ScaledSize, // 07e417c7
   ScrollEvent, // d7abdd0a
-  ScrollResponderType, // 079145bb
+  ScrollResponderType, // ba188eae
   ScrollToLocationParamsType, // d7ecdad1
-  ScrollView, // d7defbe2
-  ScrollViewImperativeMethods, // d3ff1532
-  ScrollViewInstance, // 1ba64600
-  ScrollViewProps, // 9207390b
-  ScrollViewPropsAndroid, // 44210553
-  ScrollViewPropsIOS, // da991b9a
+  ScrollView, // 066a8597
+  ScrollViewImperativeMethods, // 904c66fd
+  ScrollViewInstance, // ccf4f341
+  ScrollViewProps, // b62913d1
+  ScrollViewPropsAndroid, // 02f3df2e
+  ScrollViewPropsIOS, // 807cb4f6
   ScrollViewScrollToOptions, // 3313411e
-  SectionBase, // dca83594
-  SectionList, // f483c886
-  SectionListData, // e0d79987
-  SectionListInstance, // 1b255509
-  SectionListProps, // e06b9868
-  SectionListRenderItem, // 466e3e87
-  SectionListRenderItemInfo, // d809238e
+  SectionBase, // 9f13db00
+  SectionList, // ee3e7972
+  SectionListData, // 1a4de01a
+  SectionListInstance, // c9b991fe
+  SectionListProps, // 0e933318
+  SectionListRenderItem, // 715b2086
+  SectionListRenderItemInfo, // 4a48a922
   Separators, // 6a45f7e3
   Settings, // 2be0c61e
   Share, // e4591b32
@@ -6091,72 +6091,72 @@ export {
   ShareActionSheetIOSOptions, // eff574f5
   ShareContent, // 7c627896
   ShareOptions, // 800c3a4e
-  StatusBar, // 81b4e92f
+  StatusBar, // f95dbb76
   StatusBarAnimation, // 7fd047e6
-  StatusBarInstance, // 4e03048c
-  StatusBarProps, // bfedeab1
+  StatusBarInstance, // 416e9640
+  StatusBarProps, // c2a44d88
   StatusBarStyle, // 78f53eea
   StyleProp, // fa0e9b4a
-  StyleSheet, // cdddb9ae
+  StyleSheet, // e734acd4
   SubmitBehavior, // c4ddf490
-  Switch, // b004beeb
+  Switch, // f495bab3
   SwitchChangeEvent, // 899635b1
   SwitchInstance, // 3c50eec5
-  SwitchProps, // ded81873
+  SwitchProps, // cadfd0c4
   Systrace, // 626d178c
   TVViewPropsIOS, // 330ce7b5
   TargetedEvent, // 16e98910
   TaskProvider, // 266dedf2
-  Text, // f792e51d
+  Text, // 9ceaff08
   TextContentType, // 239b3ecc
-  TextInput, // 4d0a088b
-  TextInputAndroidProps, // 7109938a
+  TextInput, // ce1e41ff
+  TextInputAndroidProps, // 9ebbc103
   TextInputBlurEvent, // b77af40e
   TextInputChangeEvent, // f55eef98
   TextInputContentSizeChangeEvent, // a27cd32a
   TextInputEndEditingEvent, // e690b56b
   TextInputFocusEvent, // 19851a88
-  TextInputIOSProps, // 0d05a855
+  TextInputIOSProps, // fb3c9327
   TextInputInstance, // 5a0c0e0d
   TextInputKeyPressEvent, // 546c5d07
-  TextInputProps, // a56c62a0
+  TextInputProps, // c692f4de
   TextInputSelectionChangeEvent, // e58f2abc
   TextInputSubmitEditingEvent, // 6bcb2aa5
   TextInstance, // 05463a96
   TextLayoutEvent, // 3f54186f
-  TextProps, // 58466ea1
+  TextProps, // 93309fac
   TextStyle, // b62b8399
   ToastAndroid, // 88a8969a
-  TouchableHighlight, // 20ba0199
+  TouchableHighlight, // 3a6eaed4
   TouchableHighlightInstance, // b510c0eb
-  TouchableHighlightProps, // 337a9164
-  TouchableNativeFeedback, // c41fc93f
-  TouchableNativeFeedbackInstance, // e7895451
-  TouchableNativeFeedbackProps, // a645b648
-  TouchableOpacity, // 74a1b2c6
+  TouchableHighlightProps, // 00e100c4
+  TouchableNativeFeedback, // fe739e82
+  TouchableNativeFeedbackInstance, // 0877e3e4
+  TouchableNativeFeedbackProps, // 1d0c2f30
+  TouchableOpacity, // fe716ffc
   TouchableOpacityInstance, // b186055b
-  TouchableOpacityProps, // 1d3512ce
-  TouchableWithoutFeedback, // 61c63ada
-  TouchableWithoutFeedbackProps, // f4d62822
+  TouchableOpacityProps, // a3b32b69
+  TouchableWithoutFeedback, // ed159ba7
+  TouchableWithoutFeedbackProps, // e613ed05
   TransformsStyle, // 65e70f18
   TurboModule, // dfe29706
   TurboModuleRegistry, // 4ace6db2
-  UIManager, // a1a7cc01
+  UIManager, // afbcdf05
   UTFSequence, // ad625158
   Vibration, // 31e4bbf8
-  View, // 443391a0
+  View, // 3e72139a
   ViewInstance, // ffde5573
-  ViewProps, // 013135a2
-  ViewPropsAndroid, // 03c17367
+  ViewProps, // 763271bb
+  ViewPropsAndroid, // 55e81851
   ViewPropsIOS, // 58ee19bf
   ViewStyle, // e45056b1
   VirtualViewMode, // 6be59722
   VirtualizedList, // 68c7345e
   VirtualizedListInstance, // 423ee7c0
-  VirtualizedListProps, // cc8bc4c9
+  VirtualizedListProps, // f51f4a42
   VirtualizedSectionList, // 9fd9cd61
   VirtualizedSectionListInstance, // 12b706d5
-  VirtualizedSectionListProps, // 12a58a4f
+  VirtualizedSectionListProps, // 8210f30a
   WrapperComponentProvider, // 9ef54e61
   codegenNativeCommands, // 628a7c0a
   codegenNativeComponent, // 32a1bca6
@@ -6164,10 +6164,10 @@ export {
   processColor, // 6e877698
   registerCallableModule, // 839c8cfe
   requireNativeComponent, // aa36a6dd
-  useAnimatedColor, // e3511f81
-  useAnimatedValue, // b18adb63
-  useAnimatedValueXY, // c7ee2332
+  useAnimatedColor, // a9dffd9f
+  useAnimatedValue, // 25733d13
+  useAnimatedValueXY, // 04c70878
   useColorScheme, // d585efdb
-  usePressability, // 095343b5
+  usePressability, // 782138ed
   useWindowDimensions, // bb4b683f
 }

scripts/js-api/build-types/transforms/typescript/__tests__/ensureUndefinedOnOptionalMembers-test.js

@@ -0,0 +1,65 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+const ensureUndefinedOnOptionalMembersVisitor = require('../ensureUndefinedOnOptionalMembers.js');
+const babel = require('@babel/core');
+
+async function translate(code: string): Promise<string> {
+  const result = await babel.transformAsync(code, {
+    plugins: [
+      '@babel/plugin-syntax-typescript',
+      ensureUndefinedOnOptionalMembersVisitor,
+    ],
+  });
+
+  return result.code;
+}
+
+describe('ensureUndefinedOnOptionalMembers', () => {
+  test('should add undefined to optional type members', async () => {
+    const code = `
+      type Foo = {
+        a?: number,
+        'b-key'?: number | string,
+        c?: () => void,
+        d: boolean,
+        e: string | undefined,
+        f?: (() => void) | number,
+      };
+    `;
+    const result = await translate(code);
+    expect(result).toMatchInlineSnapshot(`
+      "type Foo = {
+        a?: number | undefined;
+        'b-key'?: number | string | undefined;
+        c?: (() => void) | undefined;
+        d: boolean;
+        e: string | undefined;
+        f?: (() => void) | number | undefined;
+      };"
+    `);
+  });
+
+  test('should not add undefined when already present', async () => {
+    const code = `
+      type Foo = {
+        a?: number | undefined,
+        b?: undefined,
+      };
+    `;
+    const result = await translate(code);
+    expect(result).toMatchInlineSnapshot(`
+      "type Foo = {
+        a?: number | undefined;
+        b?: undefined;
+      };"
+    `);
+  });
+});

scripts/js-api/build-types/transforms/typescript/__tests__/removeUndefinedFromOptionalMembers-test.js

@@ -42,4 +42,20 @@ describe('removeUndefinedFromOptionalMembers', () => {
       };"
     `);
   });
+
+  test('should unwrap the lone remaining constituent, dropping redundant parens', async () => {
+    const code = `
+      type Foo = {
+        a?: (() => void) | undefined,
+        b?: number | string | undefined,
+      };
+    `;
+    const result = await translate(code);
+    expect(result).toMatchInlineSnapshot(`
+      "type Foo = {
+        a?: () => void;
+        b?: number | string;
+      };"
+    `);
+  });
 });

scripts/js-api/build-types/transforms/typescript/ensureUndefinedOnOptionalMembers.js

@@ -0,0 +1,71 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import type {PluginObj} from '@babel/core';
+
+import * as t from '@babel/types';
+
+/**
+ * Ensures optional object members carry an explicit `| undefined`, e.g.
+ * `foo?: number` becomes `foo?: number | undefined` (members that already
+ * include `undefined` are left unchanged).
+ *
+ * This is the format required by TypeScript consumers building with
+ * `exactOptionalPropertyTypes`, under which `foo?: T` and `foo?: T | undefined`
+ * are distinct. It applies to the per-module generated types; the API snapshot
+ * pipeline still strips it back via `removeUndefinedFromOptionalMembers`.
+ *
+ * This lives in React Native as a stopgap: flow-api-translator does not yet emit
+ * this format, and the generated types cannot wait for its next release.
+ *
+ * The API snapshot resets this via `removeUndefinedFromOptionalMembers`, which
+ * also unwraps the resulting single-constituent unions so function-valued
+ * members remain bare function types for `sortProperties` to group.
+ */
+const visitor: PluginObj<unknown> = {
+  visitor: {
+    TSPropertySignature(path) {
+      if (path.node.optional !== true) {
+        return;
+      }
+
+      const typeAnnotation = path.node.typeAnnotation;
+      if (!typeAnnotation || !t.isTSTypeAnnotation(typeAnnotation)) {
+        return;
+      }
+
+      const actualTypeAnnotation = typeAnnotation.typeAnnotation;
+
+      if (t.isTSUndefinedKeyword(actualTypeAnnotation)) {
+        return;
+      }
+
+      if (t.isTSUnionType(actualTypeAnnotation)) {
+        if (
+          actualTypeAnnotation.types.some(type => t.isTSUndefinedKeyword(type))
+        ) {
+          return;
+        }
+        typeAnnotation.typeAnnotation = t.tsUnionType([
+          ...actualTypeAnnotation.types,
+          t.tsUndefinedKeyword(),
+        ]);
+        return;
+      }
+
+      typeAnnotation.typeAnnotation = t.tsUnionType([
+        actualTypeAnnotation,
+        t.tsUndefinedKeyword(),
+      ]);
+    },
+  },
+};
+
+module.exports = visitor;

scripts/js-api/build-types/transforms/typescript/removeUndefinedFromOptionalMembers.js

@@ -29,11 +29,27 @@ const visitor: PluginObj<unknown> = {
         return;
       }
 
-      const newTypeAnnotation = t.cloneDeep(actualTypeAnnotation);
-      newTypeAnnotation.types = newTypeAnnotation.types.filter(
+      const remainingTypes = actualTypeAnnotation.types.filter(
         type => t.isTSUndefinedKeyword(type) === false,
       );
-      typeAnnotation.typeAnnotation = newTypeAnnotation;
+      if (remainingTypes.length === actualTypeAnnotation.types.length) {
+        return;
+      }
+
+      // Unwrap to the bare type when a single constituent remains, otherwise a
+      // wrapper node survives that prints identically but breaks downstream
+      // transforms (e.g. `sortProperties`) that key on the node type. The lone
+      // constituent may be parenthesized (a function type inside a union needs
+      // parens, e.g. `(() => void) | undefined`); those parens are redundant
+      // once it is no longer part of a union.
+      if (remainingTypes.length === 1) {
+        const [remaining] = remainingTypes;
+        typeAnnotation.typeAnnotation = t.isTSParenthesizedType(remaining)
+          ? remaining.typeAnnotation
+          : remaining;
+      } else {
+        typeAnnotation.typeAnnotation = t.tsUnionType(remainingTypes);
+      }
     },
   },
 };

scripts/js-api/build-types/translateSourceFile.js

@@ -30,6 +30,7 @@ const preTransforms: Array<PreTransformFn> = [
 ];
 const postTransforms = (filePath: string): Array<PluginObj<unknown>> => [
   require('./transforms/typescript/convertTypeAliasesToInterfaces'),
+  require('./transforms/typescript/ensureUndefinedOnOptionalMembers'),
   require('./transforms/typescript/replaceProtectedConstructors'),
   require('./transforms/typescript/replaceDefaultExportName')(filePath),
 ];