fix: prevent returning items when container size is zero

examples/react/dynamic/src/main.tsx

@@ -74,7 +74,7 @@ function RowVirtualizerDynamic() {
               top: 0,
               left: 0,
               width: '100%',
-              transform: `translateY(${items[0].start}px)`,
+              transform: `translateY(${items[0]?.start ?? 0}px)`,
             }}
           >
             {items.map((virtualRow) => (
@@ -131,7 +131,7 @@ const RowVirtualizerDynamicWindow = () => {
             left: 0,
             width: '100%',
             transform: `translateY(${
-              items[0].start - virtualizer.options.scrollMargin
+              items[0] ? items[0].start - virtualizer.options.scrollMargin : 0
             }px)`,
           }}
         >

packages/react-virtual/__tests__/index.test.tsx

@@ -148,7 +148,7 @@ test('should render given dynamic size after scroll', () => {
   expect(screen.queryByText('Row 6')).toBeInTheDocument()
   expect(screen.queryByText('Row 7')).not.toBeInTheDocument()
 
-  expect(renderer).toHaveBeenCalledTimes(3)
+  expect(renderer).toHaveBeenCalledTimes(2)
 })
 
 test('should use rangeExtractor', () => {

packages/virtual-core/__tests__/index.test.ts

@@ -3,3 +3,15 @@ import { Virtualizer } from '../src/index'
 test('should export the Virtualizer class', () => {
   expect(Virtualizer).toBeDefined()
 })
+
+test('shoul', () => {
+  const virtualizer = new Virtualizer({
+    count: 100,
+    getScrollElement: () => null,
+    estimateSize: () => 50,
+    scrollToFn: jest.fn(),
+    observeElementRect: jest.fn(),
+    observeElementOffset: jest.fn(),
+  })
+  expect(virtualizer.getVirtualItems()).toEqual([])
+})

packages/virtual-core/src/index.ts

@@ -587,13 +587,16 @@ export class Virtualizer<
       this.calculateRange(),
       this.options.overscan,
       this.options.count,
+      this.getSize(),
     ],
-    (rangeExtractor, range, overscan, count) => {
-      return rangeExtractor({
-        ...range,
-        overscan,
-        count,
-      })
+    (rangeExtractor, range, overscan, count, outerSize) => {
+      return outerSize === 0
+        ? []
+        : rangeExtractor({
+            ...range,
+            overscan,
+            count,
+          })
     },
     {
       key: process.env.NODE_ENV !== 'production' && 'getIndexes',