Update return type for getNativeScrollRef methods (#56718)

Summary:
Pull Request resolved: #56718

Update the return type of `getNativeScrollRef` on `ScrollView`, `FlatList`, `SectionList` to be `PublicScrollViewInstance` (previously, a mix of `HostInstance` and `React.ElementRef<>` types which did not include the imperative methods of `ScrollView`).

- This type extends `HostInstance & ScrollViewImperativeMethods`, and is what the `ScrollView` ref chain already returns at runtime.
- The previous types were either too broad (`HostInstance`), wrong (union with `View`), or required `$FlowFixMe` suppressions.

Also removes `ScrollViewNativeComponent` from the public API surface, since it is an internal implementation detail not intended for external use (equivalent props are on the pre-existing `ScrollViewBaseProps` type).

Related to:

- #52203
- #54735

Changelog:
[General][Fixed] - **Strict TypeScript API**: Update `getNativeScrollRef` return type across ScrollView, FlatList, and SectionList

Reviewed By: zeyap

Differential Revision: D104223704

fbshipit-source-id: 7f44f91518d7f84d8a628e58095e616589a068a3

Author: huntie

packages/react-native/Libraries/Components/ScrollView/ScrollView.js

@@ -139,7 +139,7 @@ export interface ScrollViewImperativeMethods {
   +getScrollableNode: () => ?number;
   +getInnerViewNode: () => ?number;
   +getInnerViewRef: () => InnerViewInstance | null;
-  +getNativeScrollRef: () => HostInstance | null;
+  +getNativeScrollRef: () => PublicScrollViewInstance | null;
   +scrollTo: (
     options?: ScrollViewScrollToOptions | number,
     deprecatedX?: number,
@@ -872,6 +872,9 @@ class ScrollView extends React.Component<ScrollViewProps, ScrollViewState> {
 
   getNativeScrollRef: ScrollViewImperativeMethods['getNativeScrollRef'] =
     () => {
+      // Object.assign in _scrollView's mutator augments nativeInstance in place,
+      // so it is already a PublicScrollViewInstance at runtime.
+      // $FlowFixMe[incompatible-type]
       return this._scrollView.nativeInstance;
     };
 

packages/react-native/Libraries/Lists/FlatList.js

@@ -8,7 +8,7 @@
  * @format
  */
 
-import typeof ScrollViewNativeComponent from '../Components/ScrollView/ScrollViewNativeComponent';
+import type {PublicScrollViewInstance} from '../Components/ScrollView/ScrollView';
 import type {ViewStyleProp} from '../StyleSheet/StyleSheet';
 import type {
   ListRenderItem,
@@ -397,12 +397,8 @@ class FlatList<ItemT = any> extends React.PureComponent<FlatListProps<ItemT>> {
   /**
    * Provides a reference to the underlying host component
    */
-  getNativeScrollRef():
-    | ?React.ElementRef<typeof View>
-    | ?React.ElementRef<ScrollViewNativeComponent> {
+  getNativeScrollRef(): ?PublicScrollViewInstance {
     if (this._listRef) {
-      /* $FlowFixMe[incompatible-return] Suppresses errors found when fixing
-       * TextInput typing */
       return this._listRef.getScrollRef();
     }
   }

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<<d6790c241d1bd46a735efba34eeb4742>>
+ * @generated SignedSource<<82e0f2ccc327245285474ce136692c2d>>
  *
  * This file was generated by scripts/js-api/build-types/index.js.
  */
@@ -90,7 +90,6 @@ declare const $$NativeDialogManagerAndroid: null | Spec | undefined
 declare const $$ProgressBarAndroidNativeComponent: HostComponent<AndroidProgressBarNativeProps>
 declare const $$ReactFabric: typeof ReactFabric_default
 declare const $$ScrollViewContext: typeof ScrollViewContext_default
-declare const $$ScrollViewNativeComponent: typeof ScrollViewNativeComponent_default
 declare const $$SwitchNativeComponent: ComponentType
 declare const $$ViewNativeComponent: typeof ViewNativeComponent_default
 declare const absoluteFill: AbsoluteFillStyle
@@ -400,7 +399,6 @@ declare const SafeAreaView_default: (
 ) => React.ReactNode
 declare const ScrollView: typeof ScrollViewWrapper & ScrollViewComponentStatics
 declare const ScrollViewContext_default: React.Context<Value>
-declare const ScrollViewNativeComponent_default: HostComponent<ScrollViewNativeProps>
 declare const ScrollViewWrapper: (
   props: ScrollViewProps & {
     ref?: React.Ref<PublicScrollViewInstance>
@@ -1016,7 +1014,6 @@ declare type $$ProgressBarAndroidNativeComponent =
   typeof $$ProgressBarAndroidNativeComponent
 declare type $$ReactFabric = typeof $$ReactFabric
 declare type $$ScrollViewContext = typeof $$ScrollViewContext
-declare type $$ScrollViewNativeComponent = typeof $$ScrollViewNativeComponent
 declare type $$SwitchNativeComponent = typeof $$SwitchNativeComponent
 declare type $$ViewNativeComponent = typeof $$ViewNativeComponent
 declare type absoluteFill = typeof absoluteFill
@@ -2334,9 +2331,7 @@ declare class FlatList<ItemT = any> extends React.PureComponent<
   componentDidUpdate(prevProps: FlatListProps<ItemT>): void
   constructor(props: FlatListProps<ItemT>)
   flashScrollIndicators(): void
-  getNativeScrollRef():
-    | (null | React.ComponentRef<ScrollViewNativeComponent> | undefined)
-    | (null | React.ComponentRef<typeof View> | undefined)
+  getNativeScrollRef(): null | PublicScrollViewInstance | undefined
   getScrollableNode(): any
   getScrollResponder(): null | ScrollResponderType | undefined
   recordInteraction(): void
@@ -4478,7 +4473,7 @@ declare interface ScrollViewImperativeMethods {
   readonly flashScrollIndicators: () => void
   readonly getInnerViewNode: () => number | undefined
   readonly getInnerViewRef: () => InnerViewInstance | null
-  readonly getNativeScrollRef: () => HostInstance | null
+  readonly getNativeScrollRef: () => null | PublicScrollViewInstance
   readonly getScrollableNode: () => number | undefined
   readonly getScrollResponder: () => ScrollResponderType
   readonly scrollResponderScrollNativeHandleToKeyboard: (
@@ -4505,74 +4500,6 @@ declare interface ScrollViewImperativeMethods {
     options?: ScrollViewScrollToOptions | undefined,
   ) => void
 }
-declare type ScrollViewNativeComponent = typeof $$ScrollViewNativeComponent
-declare type ScrollViewNativeProps = Readonly<
-  Omit<ViewProps, "onResponderGrant"> & {
-    alwaysBounceHorizontal?: boolean
-    alwaysBounceVertical?: boolean
-    automaticallyAdjustContentInsets?: boolean
-    automaticallyAdjustKeyboardInsets?: boolean
-    automaticallyAdjustsScrollIndicatorInsets?: boolean
-    bounces?: boolean
-    bouncesZoom?: boolean
-    canCancelContentTouches?: boolean
-    centerContent?: boolean
-    contentInset?: EdgeInsetsProp
-    contentInsetAdjustmentBehavior?:
-      | "always"
-      | "automatic"
-      | "never"
-      | "scrollableAxes"
-    contentOffset?: PointProp
-    decelerationRate?: "fast" | "normal" | number
-    directionalLockEnabled?: boolean
-    disableIntervalMomentum?: boolean
-    endFillColor?: ColorValue
-    fadingEdgeLength?:
-      | (number | undefined)
-      | {
-          end: number
-          start: number
-        }
-    indicatorStyle?: "black" | "default" | "white"
-    isInvertedVirtualizedList?: boolean
-    keyboardDismissMode?: "interactive" | "none" | "on-drag"
-    maintainVisibleContentPosition?: {
-      readonly autoscrollToTopThreshold?: number
-      readonly minIndexForVisible: number
-    }
-    maximumZoomScale?: number
-    minimumZoomScale?: number
-    nestedScrollEnabled?: boolean
-    onMomentumScrollBegin?: (event: ScrollEvent) => void
-    onMomentumScrollEnd?: (event: ScrollEvent) => void
-    onResponderGrant?: (e: GestureResponderEvent) => boolean | void
-    onScroll?: (event: ScrollEvent) => void
-    onScrollBeginDrag?: (event: ScrollEvent) => void
-    onScrollEndDrag?: (event: ScrollEvent) => void
-    overScrollMode?: "always" | "auto" | "never"
-    pagingEnabled?: boolean
-    persistentScrollbar?: boolean
-    pinchGestureEnabled?: boolean
-    scrollEnabled?: boolean
-    scrollEventThrottle?: number
-    scrollIndicatorInsets?: EdgeInsetsProp
-    scrollPerfTag?: string
-    scrollsChildToFocus?: boolean
-    scrollsToTop?: boolean
-    scrollToOverflowEnabled?: boolean
-    sendMomentumEvents?: boolean
-    showsHorizontalScrollIndicator?: boolean
-    showsVerticalScrollIndicator?: boolean
-    snapToAlignment?: "center" | "end" | "start"
-    snapToEnd?: boolean
-    snapToInterval?: number
-    snapToOffsets?: ReadonlyArray<number>
-    snapToStart?: boolean
-    zoomScale?: number
-    onScrollToTop?: (event: ScrollEvent) => void
-  }
->
 declare type ScrollViewProps = Readonly<
   ViewProps & ScrollViewPropsIOS & ScrollViewPropsAndroid & ScrollViewBaseProps
 >
@@ -6067,7 +5994,7 @@ export {
   AlertOptions, // a0cdac0f
   AlertType, // 5ab91217
   AndroidKeyboardEvent, // e03becc8
-  Animated, // 0652b5d1
+  Animated, // 5254e138
   AppConfig, // ce4209a7
   AppRegistry, // 5edf0524
   AppState, // 12012be5
@@ -6114,8 +6041,8 @@ export {
   EventSubscription, // b8d084aa
   ExtendedExceptionData, // 5a6ccf5a
   FilterFunction, // bf24c0e3
-  FlatList, // 8c50f04a
-  FlatListProps, // e170f2c9
+  FlatList, // 869c5a5f
+  FlatListProps, // 2a81c428
   FocusEvent, // 62fc1eb8
   FontVariant, // 7c7558bb
   GestureResponderEvent, // f693e9a5
@@ -6250,18 +6177,18 @@ export {
   SafeAreaView, // 9589fa67
   ScaledSize, // 07e417c7
   ScrollEvent, // 5d529218
-  ScrollResponderType, // c6860ec8
+  ScrollResponderType, // 114c7cc8
   ScrollToLocationParamsType, // d7ecdad1
-  ScrollView, // a3918d1a
-  ScrollViewImperativeMethods, // 7cd8d8de
-  ScrollViewProps, // 429fdd65
+  ScrollView, // 7180dc9b
+  ScrollViewImperativeMethods, // 3f95ab77
+  ScrollViewProps, // 57e1167c
   ScrollViewPropsAndroid, // 44210553
   ScrollViewPropsIOS, // b34b696c
   ScrollViewScrollToOptions, // 3313411e
   SectionBase, // b376bddc
-  SectionList, // 92031230
+  SectionList, // c7dfd290
   SectionListData, // 119baf83
-  SectionListProps, // c0d0a46a
+  SectionListProps, // 54f880fa
   SectionListRenderItem, // 1fad0435
   SectionListRenderItemInfo, // 745e1992
   Separators, // 6a45f7e3
@@ -6326,9 +6253,9 @@ export {
   ViewStyle, // 00a0f8fb
   VirtualViewMode, // 6be59722
   VirtualizedList, // 68c7345e
-  VirtualizedListProps, // c7e8e7d7
+  VirtualizedListProps, // d414f5ca
   VirtualizedSectionList, // 9fd9cd61
-  VirtualizedSectionListProps, // 53a7e6a4
+  VirtualizedSectionListProps, // 01460821
   WrapperComponentProvider, // 9cf3844c
   codegenNativeCommands, // 628a7c0a
   codegenNativeComponent, // 2baac257