Simplify orientation cache and drop keyExtractor change

Author: secitr

packages/virtualized-lists/Lists/VirtualizeUtils.js

@@ -244,13 +244,11 @@ export function computeWindowedRenderLimits(
 }
 
 export function keyExtractor(item: any, index: number): string {
-  if (item != null && typeof item === 'object') {
-    if (item.key != null) {
-      return item.key;
-    }
-    if (item.id != null) {
-      return item.id;
-    }
+  if (typeof item === 'object' && item?.key != null) {
+    return item.key;
+  }
+  if (typeof item === 'object' && item?.id != null) {
+    return item.id;
   }
   return String(index);
 }

packages/virtualized-lists/Lists/VirtualizedList.js

@@ -1237,7 +1237,6 @@ class VirtualizedList extends StateSafePureComponent<
   }
 
   _cachedOrientation: ?ListOrientation = null;
-  _cachedOrientationHorizontal: ?boolean = null;
   _cellRefs: {[string]: null | CellRenderer<any>} = {};
   _fillRateHelper: FillRateHelper;
   _listMetrics: ListMetricsAggregator = new ListMetricsAggregator();
@@ -1566,14 +1565,13 @@ class VirtualizedList extends StateSafePureComponent<
     let cachedOrientation = this._cachedOrientation;
     if (
       cachedOrientation == null ||
-      this._cachedOrientationHorizontal !== horizontal
+      cachedOrientation.horizontal !== horizontal
     ) {
       cachedOrientation = {
         horizontal,
         rtl: I18nManager.isRTL,
       };
       this._cachedOrientation = cachedOrientation;
-      this._cachedOrientationHorizontal = horizontal;
     }
     return cachedOrientation;
   }

packages/virtualized-lists/Lists/__tests__/ChildListCollection-test.js

@@ -20,7 +20,9 @@ describe('ChildListCollection', function () {
     collection.add('c', 'cell2');
 
     const visited = [];
-    collection.forEach(list => visited.push(list));
+    collection.forEach(list => {
+      visited.push(list);
+    });
     expect(visited.sort()).toEqual(['a', 'b', 'c']);
     expect(collection.size()).toBe(3);
   });
@@ -39,7 +41,9 @@ describe('ChildListCollection', function () {
     collection.remove('a');
 
     const visited = [];
-    collection.forEach(list => visited.push(list));
+    collection.forEach(list => {
+      visited.push(list);
+    });
     expect(visited).toEqual([]);
     expect(collection.size()).toBe(0);
   });
@@ -50,7 +54,9 @@ describe('ChildListCollection', function () {
     collection.add('b', 'cell2');
 
     const visited = [];
-    collection.forEachInCell('cell1', list => visited.push(list));
+    collection.forEachInCell('cell1', list => {
+      visited.push(list);
+    });
     expect(visited).toEqual(['a']);
 
     expect(collection.anyInCell('cell2', list => list === 'b')).toBe(true);

packages/virtualized-lists/Lists/__tests__/VirtualizeUtils-test.js

@@ -16,7 +16,6 @@ import ListMetricsAggregator from '../ListMetricsAggregator';
 import {
   computeWindowedRenderLimits,
   elementsThatOverlapOffsets,
-  keyExtractor,
   newRangeCount,
 } from '../VirtualizeUtils';
 import {ReactNativeFeatureFlags} from 'react-native/react-private-interface';
@@ -293,35 +292,3 @@ describe('computeWindowedRenderLimits', function () {
     expect(result).toEqual({first: 0, last: 4});
   });
 });
-
-describe('keyExtractor', function () {
-  it('prefers item.key', function () {
-    expect(keyExtractor({key: 'k', id: 1}, 0)).toBe('k');
-  });
-
-  it('falls back to item.id when key is missing', function () {
-    expect(keyExtractor({id: 42}, 0)).toBe(42);
-  });
-
-  it('treats explicit null key as missing', function () {
-    expect(keyExtractor({key: null, id: 9}, 0)).toBe(9);
-  });
-
-  it('returns explicitly set falsy key and id values', function () {
-    expect(keyExtractor({key: 0}, 0)).toBe(0);
-    expect(keyExtractor({key: false}, 0)).toBe(false);
-    expect(keyExtractor({key: null, id: 0}, 0)).toBe(0);
-  });
-
-  it('falls back to the index for items without key or id', function () {
-    expect(keyExtractor({}, 7)).toBe('7');
-  });
-
-  it('falls back to the index for null, undefined, primitives and arrays', function () {
-    expect(keyExtractor(null, 1)).toBe('1');
-    expect(keyExtractor(undefined, 2)).toBe('2');
-    expect(keyExtractor('str', 3)).toBe('3');
-    expect(keyExtractor(42, 4)).toBe('4');
-    expect(keyExtractor([], 5)).toBe('5');
-  });
-});