Add explicit type for _memoizedRenderer and change React and View import in FlatList (#48798)

Summary:
Pull Request resolved: #48798

Changelog:
[General][Changed] - Added explicit type for _memoizedRenderer and changed React and View import in FlatList

Reviewed By: cortinico

Differential Revision: D68417026

fbshipit-source-id: 0af75381f6f8c33be10add940f0791b059de3473

Author: coado

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

@@ -19,18 +19,18 @@ import type {
 
 import * as ReactNativeFeatureFlags from '../../src/private/featureflags/ReactNativeFeatureFlags';
 import {type ScrollResponderType} from '../Components/ScrollView/ScrollView';
+import View from '../Components/View/View';
 import {
   VirtualizedList,
   keyExtractor as defaultKeyExtractor,
 } from '@react-native/virtualized-lists';
 import memoizeOne from 'memoize-one';
+import React from 'react';
 
-const View = require('../Components/View/View');
 const StyleSheet = require('../StyleSheet/StyleSheet');
 const deepDiffer = require('../Utilities/differ/deepDiffer');
 const Platform = require('../Utilities/Platform');
 const invariant = require('invariant');
-const React = require('react');
 
 type RequiredProps<ItemT> = {
   /**
@@ -672,8 +672,7 @@ class FlatList<ItemT> extends React.PureComponent<Props<ItemT>, void> {
       : {renderItem: renderProp};
   };
 
-  // $FlowFixMe[missing-local-annot]
-  _memoizedRenderer = memoizeOne(this._renderer);
+  _memoizedRenderer: ReturnType<typeof memoizeOne> = memoizeOne(this._renderer);
 
   render(): React.Node {
     const {

packages/react-native/Libraries/__tests__/__snapshots__/public-api-test.js.snap

@@ -5691,9 +5691,7 @@ declare module.exports: FillRateHelper;
 `;
 
 exports[`public API should not change unintentionally Libraries/Lists/FlatList.js 1`] = `
-"declare const View: $FlowFixMe;
-declare const React: $FlowFixMe;
-type RequiredProps<ItemT> = {
+"type RequiredProps<ItemT> = {
   data: ?$ReadOnly<$ArrayLike<ItemT>>,
 };
 type OptionalProps<ItemT> = {
@@ -5782,7 +5780,7 @@ declare class FlatList<ItemT> extends React.PureComponent<Props<ItemT>, void> {
     }) => void
   ): void;
   _renderer: $FlowFixMe;
-  _memoizedRenderer: $FlowFixMe;
+  _memoizedRenderer: ReturnType<typeof memoizeOne>;
   render(): React.Node;
 }
 declare module.exports: FlatList;