test: Add unit tests for useInfiniteVirtualization hook

Implements comprehensive unit tests for the useInfiniteVirtualization hook, covering scenarios like item loading, loading more items, and handling different loading states for the infinite scroll functionality in the table widget.

app/client/src/widgets/TableWidgetV2/component/TableBody/InifiniteScrollBody/useInfiniteVirtualization.test.tsx

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+import { renderHook } from "@testing-library/react-hooks";
+import { useInfiniteVirtualization } from "./useInfiniteVirtualization";
+import { act } from "@testing-library/react";
+import type { Row as ReactTableRowType } from "react-table";
+
+describe("useInfiniteVirtualization", () => {
+  const mockRows: ReactTableRowType<Record<string, unknown>>[] = [
+    {
+      id: "1",
+      original: { id: 1, name: "Test 1" },
+      index: 0,
+      cells: [],
+      values: {},
+      getRowProps: jest.fn(),
+      allCells: [],
+      subRows: [],
+      isExpanded: false,
+      canExpand: false,
+      depth: 0,
+      toggleRowExpanded: jest.fn(),
+      state: {},
+      toggleRowSelected: jest.fn(),
+      getToggleRowExpandedProps: jest.fn(),
+      isSelected: false,
+      isSomeSelected: false,
+      isGrouped: false,
+      groupByID: "",
+      groupByVal: "",
+      leafRows: [],
+      getToggleRowSelectedProps: jest.fn(),
+      setState: jest.fn(),
+    },
+    {
+      id: "2",
+      original: { id: 2, name: "Test 2" },
+      index: 1,
+      cells: [],
+      values: {},
+      getRowProps: jest.fn(),
+      allCells: [],
+      subRows: [],
+      isExpanded: false,
+      canExpand: false,
+      depth: 0,
+      toggleRowExpanded: jest.fn(),
+      state: {},
+      toggleRowSelected: jest.fn(),
+      getToggleRowExpandedProps: jest.fn(),
+      isSelected: false,
+      isSomeSelected: false,
+      isGrouped: false,
+      groupByID: "",
+      groupByVal: "",
+      leafRows: [],
+      getToggleRowSelectedProps: jest.fn(),
+      setState: jest.fn(),
+    },
+  ];
+
+  const defaultProps = {
+    rows: mockRows,
+    isLoading: false,
+    loadMore: jest.fn(),
+    pageSize: 10,
+  };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it("should return correct itemCount when totalRecordsCount is provided", () => {
+    const totalRecordsCount = 100;
+    const { result } = renderHook(() =>
+      useInfiniteVirtualization({
+        ...defaultProps,
+        totalRecordsCount,
+      }),
+    );
+
+    expect(result.current.itemCount).toBe(totalRecordsCount);
+  });
+
+  it("should return rows length as itemCount when totalRecordsCount is not provided", () => {
+    const { result } = renderHook(() =>
+      useInfiniteVirtualization(defaultProps),
+    );
+
+    expect(result.current.itemCount).toBe(defaultProps.rows.length);
+  });
+
+  it("should call loadMore when loadMoreItems is called and not loading", async () => {
+    const { result } = renderHook(() =>
+      useInfiniteVirtualization(defaultProps),
+    );
+
+    await act(async () => {
+      await result.current.loadMoreItems(0, 10);
+    });
+
+    expect(defaultProps.loadMore).toHaveBeenCalledTimes(1);
+  });
+
+  it("should not call loadMore when loadMoreItems is called and is loading", async () => {
+    const { result } = renderHook(() =>
+      useInfiniteVirtualization({
+        ...defaultProps,
+        isLoading: true,
+      }),
+    );
+
+    await act(async () => {
+      await result.current.loadMoreItems(0, 10);
+    });
+
+    expect(defaultProps.loadMore).not.toHaveBeenCalled();
+  });
+
+  it("should return correct isItemLoaded state for different scenarios", () => {
+    const { result } = renderHook(() =>
+      useInfiniteVirtualization(defaultProps),
+    );
+
+    // Index within rows length and not loading
+    expect(result.current.isItemLoaded(1)).toBe(true);
+
+    // Index beyond rows length and not loading
+    expect(result.current.isItemLoaded(5)).toBe(false);
+  });
+
+  it("should return false for isItemLoaded when loading", () => {
+    const { result } = renderHook(() =>
+      useInfiniteVirtualization({
+        ...defaultProps,
+        isLoading: true,
+      }),
+    );
+
+    // Even for index within rows length, should return false when loading
+    expect(result.current.isItemLoaded(1)).toBe(false);
+  });
+
+  it("should return zero itemCount when there are no records", () => {
+    const { result } = renderHook(() =>
+      useInfiniteVirtualization({
+        ...defaultProps,
+        rows: [],
+      }),
+    );
+
+    expect(result.current.itemCount).toBe(0);
+  });
+});