fix: fix virtualizedList scrollToEnd for 0 items (facebook#36067)

Summary:
Fixes facebook#36066

## Changelog

[GENERAL] [FIXED] - VirtualizedList scrollToEnd with no data

Pull Request resolved: facebook#36067

Test Plan: Run `yarn test VirtualizedList-test`

Reviewed By: jacdebug

Differential Revision: D43041763

Pulled By: javache

fbshipit-source-id: d4d5e871284708a89bf9911d82e9aa97d7625aca

Libraries/Lists/VirtualizedList.js

@@ -167,6 +167,9 @@ export default class VirtualizedList extends StateSafePureComponent<
   scrollToEnd(params?: ?{animated?: ?boolean, ...}) {
     const animated = params ? params.animated : true;
     const veryLast = this.props.getItemCount(this.props.data) - 1;
+    if (veryLast < 0) {
+      return;
+    }
     const frame = this.__getFrameMetricsApprox(veryLast, this.props);
     const offset = Math.max(
       0,

Libraries/Lists/__tests__/VirtualizedList-test.js

@@ -137,6 +137,20 @@ describe('VirtualizedList', () => {
     expect(component).toMatchSnapshot();
   });
 
+  it('scrollToEnd works with null list', () => {
+    const listRef = React.createRef(null);
+    ReactTestRenderer.create(
+      <VirtualizedList
+        data={undefined}
+        renderItem={({item}) => <item value={item.key} />}
+        getItem={(data, index) => data[index]}
+        getItemCount={data => 0}
+        ref={listRef}
+      />,
+    );
+    listRef.current.scrollToEnd();
+  });
+
   it('renders empty list with empty component', () => {
     const component = ReactTestRenderer.create(
       <VirtualizedList