Back out "Update typed export and fix test", Back out "[VirtualizedSectionList] Remove defaultProps", Back out "[VirtualizedList] Remove keyExtractor defaultProps"

Summary:
Changelog:
Partial revert the stack

Reviewed By: makovkastar

Differential Revision: D27156625

fbshipit-source-id: b158c9102047bb64ce708b200a8e5786f5a0c176

Libraries/Lists/FlatList.js

@@ -25,7 +25,6 @@ import type {
   ViewabilityConfigCallbackPair,
 } from './ViewabilityHelper';
 import type {RenderItemType, RenderItemProps} from './VirtualizedList';
-import {keyExtractor as defaultKeyExtractor} from './VirtualizeUtils';
 
 type RequiredProps<ItemT> = {|
   /**
@@ -121,7 +120,7 @@ type OptionalProps<ItemT> = {|
    * and as the react key to track item re-ordering. The default extractor checks `item.key`, then
    * falls back to using the index, like React does.
    */
-  keyExtractor?: ?(item: ItemT, index: number) => string,
+  keyExtractor: (item: ItemT, index: number) => string,
   /**
    * Multiple columns can only be rendered with `horizontal={false}` and will zig-zag like a
    * `flexWrap` layout. Items should all be the same height - masonry layouts are not supported.
@@ -157,6 +156,7 @@ export type Props<ItemT> = {
 };
 
 const defaultProps = {
+  ...VirtualizedList.defaultProps,
   numColumns: 1,
   /**
    * Enabling this prop on Android greatly improves scrolling performance with no known issues.
@@ -503,24 +503,20 @@ class FlatList<ItemT> extends React.PureComponent<Props<ItemT>, void> {
   };
 
   _keyExtractor = (items: ItemT | Array<ItemT>, index: number) => {
-    const {numColumns} = this.props;
-    const keyExtractor = this.props.keyExtractor ?? defaultKeyExtractor;
-
+    const {keyExtractor, numColumns} = this.props;
     if (numColumns > 1) {
-      if (Array.isArray(items)) {
-        return items
-          .map((item, kk) =>
-            keyExtractor(((item: $FlowFixMe): ItemT), index * numColumns + kk),
-          )
-          .join(':');
-      } else {
-        invariant(
-          Array.isArray(items),
-          'FlatList: Encountered internal consistency error, expected each item to consist of an ' +
-            'array with 1-%s columns; instead, received a single item.',
-          numColumns,
-        );
-      }
+      invariant(
+        Array.isArray(items),
+        'FlatList: Encountered internal consistency error, expected each item to consist of an ' +
+          'array with 1-%s columns; instead, received a single item.',
+        numColumns,
+      );
+      return (
+        items
+          // $FlowFixMe[incompatible-call]
+          .map((it, kk) => keyExtractor(it, index * numColumns + kk))
+          .join(':')
+      );
     } else {
       // $FlowFixMe Can't call keyExtractor with an array
       return keyExtractor(items, index);
@@ -528,8 +524,7 @@ class FlatList<ItemT> extends React.PureComponent<Props<ItemT>, void> {
   };
 
   _pushMultiColumnViewable(arr: Array<ViewToken>, v: ViewToken): void {
-    const {numColumns} = this.props;
-    const keyExtractor = this.props.keyExtractor ?? defaultKeyExtractor;
+    const {numColumns, keyExtractor} = this.props;
     v.item.forEach((item, ii) => {
       invariant(v.index != null, 'Missing index!');
       const index = v.index * numColumns + ii;

Libraries/Lists/SectionList.js

@@ -78,7 +78,7 @@ type OptionalProps<SectionT: SectionBase<any>> = {|
    * falls back to using the index, like react does. Note that this sets keys for each item, but
    * each overall section still needs its own key.
    */
-  keyExtractor?: ?(item: Item, index: number) => string,
+  keyExtractor: (item: Item, index: number) => string,
   /**
    * Called once when the scroll position gets within `onEndReachedThreshold` of the rendered
    * content.
@@ -105,10 +105,6 @@ export type Props<SectionT> = {|
         VirtualizedSectionListProps<SectionT>,
         'renderItem',
       >,
-      keyExtractor: $PropertyType<
-        VirtualizedSectionListProps<SectionT>,
-        'keyExtractor',
-      >,
       ...
     },
   >,
@@ -117,6 +113,7 @@ export type Props<SectionT> = {|
 |};
 
 const defaultProps = {
+  ...VirtualizedSectionList.defaultProps,
   stickySectionHeadersEnabled: Platform.OS === 'ios',
 };
 

Libraries/Lists/VirtualizeUtils.js

@@ -233,13 +233,3 @@ export function computeWindowedRenderLimits(
   }
   return {first, last};
 }
-
-export function keyExtractor(item: any, index: number): string {
-  if (typeof item === 'object' && item?.key != null) {
-    return item.key;
-  }
-  if (typeof item === 'object' && item?.id != null) {
-    return item.id;
-  }
-  return String(index);
-}

Libraries/Lists/VirtualizedList.js

@@ -22,10 +22,7 @@ const infoLog = require('../Utilities/infoLog');
 const invariant = require('invariant');
 import VirtualizedListInjection from './VirtualizedListInjection';
 
-import {
-  keyExtractor as defaultKeyExtractor,
-  computeWindowedRenderLimits,
-} from './VirtualizeUtils';
+import {computeWindowedRenderLimits} from './VirtualizeUtils';
 
 import * as React from 'react';
 import type {ScrollResponderType} from '../Components/ScrollView/ScrollView';
@@ -135,7 +132,7 @@ type OptionalProps = {|
    * Reverses the direction of scroll. Uses scale transforms of -1.
    */
   inverted?: ?boolean,
-  keyExtractor?: ?(item: Item, index: number) => string,
+  keyExtractor: (item: Item, index: number) => string,
   /**
    * Each cell is rendered using this element. Can be a React Component Class,
    * or a render function. Defaults to using View.
@@ -306,6 +303,10 @@ type Props = {|
   ...OptionalProps,
 |};
 
+type DefaultProps = {|
+  keyExtractor: (item: Item, index: number) => string,
+|};
+
 let _usedIndexForKey = false;
 let _keylessItemComponentName: string = '';
 
@@ -314,37 +315,26 @@ type State = {
   last: number,
 };
 
-/**
- * Default Props Helper Functions
- * Use the following helper functions for default values
- */
-
-// horizontalOrDefault(this.props.horizontal)
 function horizontalOrDefault(horizontal: ?boolean) {
   return horizontal ?? false;
 }
 
-// initialNumToRenderOrDefault(this.props.initialNumToRenderOrDefault)
 function initialNumToRenderOrDefault(initialNumToRender: ?number) {
   return initialNumToRender ?? 10;
 }
 
-// maxToRenderPerBatchOrDefault(this.props.maxToRenderPerBatch)
 function maxToRenderPerBatchOrDefault(maxToRenderPerBatch: ?number) {
   return maxToRenderPerBatch ?? 10;
 }
 
-// onEndReachedThresholdOrDefault(this.props.onEndReachedThreshold)
 function onEndReachedThresholdOrDefault(onEndReachedThreshold: ?number) {
   return onEndReachedThreshold ?? 2;
 }
 
-// scrollEventThrottleOrDefault(this.props.scrollEventThrottle)
 function scrollEventThrottleOrDefault(scrollEventThrottle: ?number) {
   return scrollEventThrottle ?? 50;
 }
 
-// windowSizeOrDefault(this.props.windowSize)
 function windowSizeOrDefault(windowSize: ?number) {
   return windowSize ?? 21;
 }
@@ -375,7 +365,6 @@ function windowSizeOrDefault(windowSize: ?number) {
  *   and we are working on improving it behind the scenes.
  * - By default, the list looks for a `key` or `id` prop on each item and uses that for the React key.
  *   Alternatively, you can provide a custom `keyExtractor` prop.
- * - As an effort to remove defaultProps, use helper functions when referencing certain props
  *
  */
 class VirtualizedList extends React.PureComponent<Props, State> {
@@ -591,6 +580,22 @@ class VirtualizedList extends React.PureComponent<Props, State> {
     }
   }
 
+  static defaultProps: DefaultProps = {
+    keyExtractor: (item: Item, index: number) => {
+      if (item.key != null) {
+        return item.key;
+      }
+      if (item.id != null) {
+        return item.id;
+      }
+      _usedIndexForKey = true;
+      if (item.type && item.type.displayName) {
+        _keylessItemComponentName = item.type.displayName;
+      }
+      return String(index);
+    },
+  };
+
   _getCellKey(): string {
     return this.context?.cellKey || 'rootList';
   }
@@ -799,6 +804,7 @@ class VirtualizedList extends React.PureComponent<Props, State> {
       getItem,
       getItemCount,
       horizontal,
+      keyExtractor,
     } = this.props;
     const stickyOffset = this.props.ListHeaderComponent ? 1 : 0;
     const end = getItemCount(data) - 1;
@@ -806,7 +812,7 @@ class VirtualizedList extends React.PureComponent<Props, State> {
     last = Math.min(end, last);
     for (let ii = first; ii <= last; ii++) {
       const item = getItem(data, ii);
-      const key = this._keyExtractor(item, ii);
+      const key = keyExtractor(item, ii);
       this._indicesToKeys.set(ii, key);
       if (stickyIndicesFromProps.has(ii + stickyOffset)) {
         stickyHeaderIndices.push(cells.length);
@@ -858,21 +864,6 @@ class VirtualizedList extends React.PureComponent<Props, State> {
   _getSpacerKey = (isVertical: boolean): string =>
     isVertical ? 'height' : 'width';
 
-  _keyExtractor(item: Item, index: number) {
-    if (this.props.keyExtractor != null) {
-      return this.props.keyExtractor(item, index);
-    }
-
-    const key = defaultKeyExtractor(item, index);
-    if (key === String(index)) {
-      _usedIndexForKey = true;
-      if (item.type && item.type.displayName) {
-        _keylessItemComponentName = item.type.displayName;
-      }
-    }
-    return key;
-  }
-
   render(): React.Node {
     if (__DEV__) {
       const flatStyles = flattenStyle(this.props.contentContainerStyle);
@@ -1825,9 +1816,9 @@ class VirtualizedList extends React.PureComponent<Props, State> {
   };
 
   _createViewToken = (index: number, isViewable: boolean) => {
-    const {data, getItem} = this.props;
+    const {data, getItem, keyExtractor} = this.props;
     const item = getItem(data, index);
-    return {index, item, key: this._keyExtractor(item, index), isViewable};
+    return {index, item, key: keyExtractor(item, index), isViewable};
   };
 
   _getFrameMetricsApprox = (
@@ -1863,13 +1854,19 @@ class VirtualizedList extends React.PureComponent<Props, State> {
     inLayout?: boolean,
     ...
   } => {
-    const {data, getItem, getItemCount, getItemLayout} = this.props;
+    const {
+      data,
+      getItem,
+      getItemCount,
+      getItemLayout,
+      keyExtractor,
+    } = this.props;
     invariant(
       getItemCount(data) > index,
       'Tried to get frame for out of range index ' + index,
     );
     const item = getItem(data, index);
-    let frame = item && this._frames[this._keyExtractor(item, index)];
+    let frame = item && this._frames[keyExtractor(item, index)];
     if (!frame || frame.index !== index) {
       if (getItemLayout) {
         frame = getItemLayout(data, index);

Libraries/Lists/VirtualizedSectionList.js

@@ -17,7 +17,6 @@ const VirtualizedList = require('./VirtualizedList');
 const invariant = require('invariant');
 
 import type {ViewToken} from './ViewabilityHelper';
-import {keyExtractor as defaultKeyExtractor} from './VirtualizeUtils';
 
 type Item = any;
 
@@ -100,18 +99,14 @@ type OptionalProps<SectionT: SectionBase<any>> = {|
   onEndReached?: ?({distanceFromEnd: number, ...}) => void,
 |};
 
-type VirtualizedListProps = React.ElementConfig<typeof VirtualizedList>;
+type VirtualizedListProps = React.ElementProps<typeof VirtualizedList>;
 
 export type Props<SectionT> = {|
   ...RequiredProps<SectionT>,
   ...OptionalProps<SectionT>,
   ...$Diff<
     VirtualizedListProps,
-    {
-      renderItem: $PropertyType<VirtualizedListProps, 'renderItem'>,
-      data: $PropertyType<VirtualizedListProps, 'data'>,
-      ...
-    },
+    {renderItem: $PropertyType<VirtualizedListProps, 'renderItem'>, ...},
   >,
 |};
 export type ScrollToLocationParamsType = {|
@@ -122,6 +117,11 @@ export type ScrollToLocationParamsType = {|
   viewPosition?: number,
 |};
 
+type DefaultProps = {|
+  ...typeof VirtualizedList.defaultProps,
+  data: $ReadOnlyArray<Item>,
+|};
+
 type State = {childProps: VirtualizedListProps, ...};
 
 /**
@@ -132,6 +132,11 @@ type State = {childProps: VirtualizedListProps, ...};
 class VirtualizedSectionList<
   SectionT: SectionBase<any>,
 > extends React.PureComponent<Props<SectionT>, State> {
+  static defaultProps: DefaultProps = {
+    ...VirtualizedList.defaultProps,
+    data: [],
+  };
+
   scrollToLocation(params: ScrollToLocationParamsType) {
     let index = params.itemIndex;
     for (let i = 0; i < params.sectionIndex; i++) {
@@ -212,11 +217,11 @@ class VirtualizedSectionList<
     );
   }
 
-  _getItem(
+  _getItem = (
     props: Props<SectionT>,
     sections: ?$ReadOnlyArray<Item>,
     index: number,
-  ): ?Item {
+  ): ?Item => {
     if (!sections) {
       return null;
     }
@@ -238,7 +243,7 @@ class VirtualizedSectionList<
       }
     }
     return null;
-  }
+  };
 
   _keyExtractor = (item: Item, index: number) => {
     const info = this._subExtractor(index);
@@ -287,8 +292,7 @@ class VirtualizedSectionList<
           trailingSection: sections[i + 1],
         };
       } else {
-        const extractor =
-          section.keyExtractor || keyExtractor || defaultKeyExtractor;
+        const extractor = section.keyExtractor || keyExtractor;
         return {
           section,
           key:
@@ -577,11 +581,4 @@ class ItemWithSeparator extends React.Component<
   }
 }
 
-module.exports = (VirtualizedSectionList: React.AbstractComponent<
-  React.ElementConfig<typeof VirtualizedSectionList>,
-  $ReadOnly<{
-    getListRef: () => ?React.ElementRef<typeof VirtualizedList>,
-    scrollToLocation: (params: ScrollToLocationParamsType) => void,
-    ...
-  }>,
->);
+module.exports = VirtualizedSectionList;

Libraries/Lists/__tests__/VirtualizedSectionList-test.js

@@ -103,37 +103,26 @@ describe('VirtualizedSectionList', () => {
 
   it('handles separators correctly', () => {
     const infos = [];
-    let component;
-    ReactTestRenderer.act(() => {
-      component = ReactTestRenderer.create(
-        <VirtualizedSectionList
-          ItemSeparatorComponent={props => <separator {...props} />}
-          sections={[
-            {title: 's0', data: [{key: 'i0'}, {key: 'i1'}, {key: 'i2'}]},
-          ]}
-          renderItem={info => {
-            infos.push(info);
-            return <item title={info.item.key} />;
-          }}
-          getItem={(data, key) => data[key]}
-          getItemCount={data => data.length}
-        />,
-      );
-    });
+    const component = ReactTestRenderer.create(
+      <VirtualizedSectionList
+        ItemSeparatorComponent={props => <separator {...props} />}
+        sections={[
+          {title: 's0', data: [{key: 'i0'}, {key: 'i1'}, {key: 'i2'}]},
+        ]}
+        renderItem={info => {
+          infos.push(info);
+          return <item title={info.item.key} />;
+        }}
+        getItem={(data, key) => data[key]}
+        getItemCount={data => data.length}
+      />,
+    );
     expect(component).toMatchSnapshot();
-
-    ReactTestRenderer.act(() => {
-      infos[1].separators.highlight();
-    });
+    infos[1].separators.highlight();
     expect(component).toMatchSnapshot();
-    ReactTestRenderer.act(() => {
-      infos[2].separators.updateProps('leading', {press: true});
-    });
-    expect(component).toMatchSnapshot();
-    ReactTestRenderer.act(() => {
-      infos[1].separators.unhighlight();
-    });
+    infos[2].separators.updateProps('leading', {press: true});
     expect(component).toMatchSnapshot();
+    infos[1].separators.unhighlight();
   });
 
   it('handles nested lists', () => {

Libraries/Lists/__tests__/__snapshots__/VirtualizedList-test.js.snap

@@ -44,6 +44,7 @@ exports[`VirtualizedList forwards correct stickyHeaderIndices when all in initia
   getItemCount={[Function]}
   getItemLayout={[Function]}
   initialNumToRender={10}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -185,6 +186,7 @@ exports[`VirtualizedList forwards correct stickyHeaderIndices when partially in
   getItemCount={[Function]}
   getItemLayout={[Function]}
   initialNumToRender={5}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -264,6 +266,7 @@ exports[`VirtualizedList handles nested lists 1`] = `
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -294,6 +297,7 @@ exports[`VirtualizedList handles nested lists 1`] = `
         getItem={[Function]}
         getItemCount={[Function]}
         horizontal={false}
+        keyExtractor={[Function]}
         onContentSizeChange={[Function]}
         onLayout={[Function]}
         onMomentumScrollBegin={[Function]}
@@ -341,6 +345,7 @@ exports[`VirtualizedList handles nested lists 1`] = `
         getItem={[Function]}
         getItemCount={[Function]}
         horizontal={true}
+        keyExtractor={[Function]}
         onContentSizeChange={[Function]}
         onLayout={[Function]}
         onMomentumScrollBegin={[Function]}
@@ -408,6 +413,7 @@ exports[`VirtualizedList handles separators correctly 1`] = `
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -482,6 +488,7 @@ exports[`VirtualizedList handles separators correctly 2`] = `
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -556,6 +563,7 @@ exports[`VirtualizedList handles separators correctly 3`] = `
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -703,6 +711,7 @@ exports[`VirtualizedList keeps sticky headers realized after scrolled out of vie
   getItemCount={[Function]}
   getItemLayout={[Function]}
   initialNumToRender={1}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -891,6 +900,7 @@ exports[`VirtualizedList realizes sticky headers in viewport on batched render 1
   getItemCount={[Function]}
   getItemLayout={[Function]}
   initialNumToRender={1}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -1162,6 +1172,7 @@ exports[`VirtualizedList renders empty list 1`] = `
   data={Array []}
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -1185,6 +1196,7 @@ exports[`VirtualizedList renders empty list with empty component 1`] = `
   data={Array []}
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -1224,6 +1236,7 @@ exports[`VirtualizedList renders list with empty component 1`] = `
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -1252,6 +1265,7 @@ exports[`VirtualizedList renders null list 1`] = `
 <RCTScrollView
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -1284,6 +1298,7 @@ exports[`VirtualizedList renders simple list 1`] = `
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -1342,6 +1357,7 @@ exports[`VirtualizedList renders simple list using ListItemComponent 1`] = `
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -1392,6 +1408,7 @@ exports[`VirtualizedList test getItem functionality where data is not an Array 1
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}
@@ -1428,6 +1445,7 @@ exports[`VirtualizedList warns if both renderItem or ListItemComponent are speci
   }
   getItem={[Function]}
   getItemCount={[Function]}
+  keyExtractor={[Function]}
   onContentSizeChange={[Function]}
   onLayout={[Function]}
   onMomentumScrollBegin={[Function]}

Libraries/Lists/__tests__/__snapshots__/VirtualizedSectionList-test.js.snap

@@ -596,140 +596,6 @@ exports[`VirtualizedSectionList handles separators correctly 3`] = `
 </RCTScrollView>
 `;
 
-exports[`VirtualizedSectionList handles separators correctly 4`] = `
-<RCTScrollView
-  data={
-    Array [
-      Object {
-        "data": Array [
-          Object {
-            "key": "i0",
-          },
-          Object {
-            "key": "i1",
-          },
-          Object {
-            "key": "i2",
-          },
-        ],
-        "title": "s0",
-      },
-    ]
-  }
-  getItem={[Function]}
-  getItemCount={[Function]}
-  keyExtractor={[Function]}
-  onContentSizeChange={[Function]}
-  onLayout={[Function]}
-  onMomentumScrollBegin={[Function]}
-  onMomentumScrollEnd={[Function]}
-  onScroll={[Function]}
-  onScrollBeginDrag={[Function]}
-  onScrollEndDrag={[Function]}
-  renderItem={[Function]}
-  scrollEventThrottle={50}
-  stickyHeaderIndices={Array []}
->
-  <View>
-    <View
-      onLayout={[Function]}
-      style={null}
-    />
-    <View
-      onLayout={[Function]}
-      style={null}
-    >
-      <View>
-        <item
-          title="i0"
-        />
-        <separator
-          highlighted={false}
-          leadingItem={
-            Object {
-              "key": "i0",
-            }
-          }
-          section={
-            Object {
-              "data": Array [
-                Object {
-                  "key": "i0",
-                },
-                Object {
-                  "key": "i1",
-                },
-                Object {
-                  "key": "i2",
-                },
-              ],
-              "title": "s0",
-            }
-          }
-          trailingItem={
-            Object {
-              "key": "i1",
-            }
-          }
-        />
-      </View>
-    </View>
-    <View
-      onLayout={[Function]}
-      style={null}
-    >
-      <View>
-        <item
-          title="i1"
-        />
-        <separator
-          highlighted={false}
-          leadingItem={
-            Object {
-              "key": "i1",
-            }
-          }
-          press={true}
-          section={
-            Object {
-              "data": Array [
-                Object {
-                  "key": "i0",
-                },
-                Object {
-                  "key": "i1",
-                },
-                Object {
-                  "key": "i2",
-                },
-              ],
-              "title": "s0",
-            }
-          }
-          trailingItem={
-            Object {
-              "key": "i2",
-            }
-          }
-        />
-      </View>
-    </View>
-    <View
-      onLayout={[Function]}
-      style={null}
-    >
-      <item
-        title="i2"
-      />
-    </View>
-    <View
-      onLayout={[Function]}
-      style={null}
-    />
-  </View>
-</RCTScrollView>
-`;
-
 exports[`VirtualizedSectionList renders all the bells and whistles 1`] = `
 <RCTScrollView
   ListEmptyComponent={[Function]}