test(drill-detail): cover download handlers for CSV/XLSX flows

Adds unit tests for DownloadDropdown menu clicks and integration tests
for DrillDetailPane (asserts SupersetClient.postForm payload: result_type
'drill_detail', ROW_LIMIT, dashboardId) and DrillByModal (asserts
exportChart called with correct resultFormat).

Bumps patch coverage on new download logic from ~45% toward full
coverage of the added code paths.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

superset-frontend/src/components/Chart/DrillBy/DrillByModal.test.tsx

@@ -40,6 +40,19 @@ jest.mock('src/dashboard/util/isEmbedded', () => ({
   isEmbedded: jest.fn(() => false),
 }));
 
+jest.mock('src/explore/exploreUtils', () => {
+  const actual = jest.requireActual('src/explore/exploreUtils');
+  return {
+    ...actual,
+    exportChart: jest.fn(),
+  };
+});
+
+// eslint-disable-next-line @typescript-eslint/no-var-requires
+const { exportChart: exportChartMock } = jest.requireMock(
+  'src/explore/exploreUtils',
+) as { exportChart: jest.Mock };
+
 const CHART_DATA_ENDPOINT = 'glob:*/api/v1/chart/data*';
 const FORM_DATA_KEY_ENDPOINT = 'glob:*/api/v1/explore/form_data';
 
@@ -553,4 +566,64 @@ describe('Table view with pagination', () => {
     // Table should still be rendered without crashes
     expect(screen.getByTestId('drill-by-results-table')).toBeInTheDocument();
   });
+
+  test('CSV download calls exportChart with drilledFormData', async () => {
+    exportChartMock.mockClear();
+    await renderModal({
+      column: { column_name: 'state', verbose_name: null },
+      drillByConfig: {
+        filters: [{ col: 'gender', op: '==', val: 'boy' }],
+        groupbyFieldName: 'groupby',
+      },
+    });
+
+    const tableRadio = await screen.findByRole('radio', { name: /table/i });
+    userEvent.click(tableRadio);
+    await waitFor(() =>
+      expect(screen.getByTestId('drill-by-results-table')).toBeInTheDocument(),
+    );
+
+    await userEvent.click(
+      await screen.findByRole('button', { name: 'Download' }),
+    );
+    await userEvent.click(await screen.findByText('Export to CSV'));
+
+    expect(exportChartMock).toHaveBeenCalledTimes(1);
+    expect(exportChartMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        resultFormat: 'csv',
+        resultType: 'full',
+      }),
+    );
+  });
+
+  test('XLSX download calls exportChart with xlsx format', async () => {
+    exportChartMock.mockClear();
+    await renderModal({
+      column: { column_name: 'state', verbose_name: null },
+      drillByConfig: {
+        filters: [{ col: 'gender', op: '==', val: 'boy' }],
+        groupbyFieldName: 'groupby',
+      },
+    });
+
+    const tableRadio = await screen.findByRole('radio', { name: /table/i });
+    userEvent.click(tableRadio);
+    await waitFor(() =>
+      expect(screen.getByTestId('drill-by-results-table')).toBeInTheDocument(),
+    );
+
+    await userEvent.click(
+      await screen.findByRole('button', { name: 'Download' }),
+    );
+    await userEvent.click(await screen.findByText('Export to Excel'));
+
+    expect(exportChartMock).toHaveBeenCalledTimes(1);
+    expect(exportChartMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        resultFormat: 'xlsx',
+        resultType: 'full',
+      }),
+    );
+  });
 });

superset-frontend/src/components/Chart/DrillDetail/DownloadDropdown.test.tsx

@@ -0,0 +1,57 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+import { render, screen, userEvent } from 'spec/helpers/testing-library';
+import DownloadDropdown from './DownloadDropdown';
+
+const onDownloadCSV = jest.fn();
+const onDownloadXLSX = jest.fn();
+
+beforeEach(() => {
+  onDownloadCSV.mockClear();
+  onDownloadXLSX.mockClear();
+});
+
+const setup = () =>
+  render(
+    <DownloadDropdown
+      onDownloadCSV={onDownloadCSV}
+      onDownloadXLSX={onDownloadXLSX}
+    />,
+  );
+
+test('renders a download trigger with accessible label', () => {
+  setup();
+  expect(screen.getByRole('button', { name: 'Download' })).toBeInTheDocument();
+});
+
+test('fires onDownloadCSV when CSV menu item is selected', async () => {
+  setup();
+  await userEvent.click(screen.getByRole('button', { name: 'Download' }));
+  await userEvent.click(await screen.findByText('Export to CSV'));
+  expect(onDownloadCSV).toHaveBeenCalledTimes(1);
+  expect(onDownloadXLSX).not.toHaveBeenCalled();
+});
+
+test('fires onDownloadXLSX when Excel menu item is selected', async () => {
+  setup();
+  await userEvent.click(screen.getByRole('button', { name: 'Download' }));
+  await userEvent.click(await screen.findByText('Export to Excel'));
+  expect(onDownloadXLSX).toHaveBeenCalledTimes(1);
+  expect(onDownloadCSV).not.toHaveBeenCalled();
+});

superset-frontend/src/components/Chart/DrillDetail/DrillDetailPane.test.tsx

@@ -18,7 +18,12 @@
  */
 import fetchMock from 'fetch-mock';
 import { QueryFormData, SupersetClient } from '@superset-ui/core';
-import { render, screen, waitFor } from 'spec/helpers/testing-library';
+import {
+  render,
+  screen,
+  userEvent,
+  waitFor,
+} from 'spec/helpers/testing-library';
 import { getMockStoreWithNativeFilters } from 'spec/fixtures/mockStore';
 import chartQueries, { sliceId } from 'spec/fixtures/mockChartQueries';
 import { supersetGetCache } from 'src/utils/cachedSupersetGet';
@@ -189,6 +194,66 @@ test('should render the error', async () => {
   expect(screen.getByText('Error: Something went wrong')).toBeInTheDocument();
 });
 
+describe('download actions', () => {
+  const renderWithDownloadPermission = () =>
+    render(
+      <DrillDetailPane
+        initialFilters={[]}
+        formData={chart.form_data as unknown as QueryFormData}
+      />,
+      {
+        useRedux: true,
+        initialState: {
+          user: { roles: { Admin: [['can_csv', 'Superset']] } },
+          common: { conf: { SAMPLES_ROW_LIMIT: 10, ROW_LIMIT: 50000 } },
+          dashboardInfo: { id: 123 },
+        },
+      },
+    );
+
+  const clickDownloadItem = async (label: string) => {
+    await userEvent.click(
+      await screen.findByRole('button', { name: 'Download' }),
+    );
+    await userEvent.click(await screen.findByText(label));
+  };
+
+  test('CSV export posts drill_detail payload with ROW_LIMIT', async () => {
+    fetchWithData();
+    const postFormSpy = jest
+      .spyOn(SupersetClient, 'postForm')
+      .mockImplementation(() => Promise.resolve());
+    renderWithDownloadPermission();
+
+    await clickDownloadItem('Export to CSV');
+
+    expect(postFormSpy).toHaveBeenCalledTimes(1);
+    const body = postFormSpy.mock.calls[0][1] as { form_data: string };
+    const payload = JSON.parse(body.form_data);
+    expect(payload.result_type).toBe('drill_detail');
+    expect(payload.result_format).toBe('csv');
+    expect(payload.queries[0].row_limit).toBe(50000);
+    expect(payload.form_data.dashboardId).toBe(123);
+    postFormSpy.mockRestore();
+  });
+
+  test('XLSX export uses xlsx result_format', async () => {
+    fetchWithData();
+    const postFormSpy = jest
+      .spyOn(SupersetClient, 'postForm')
+      .mockImplementation(() => Promise.resolve());
+    renderWithDownloadPermission();
+
+    await clickDownloadItem('Export to Excel');
+
+    expect(postFormSpy).toHaveBeenCalledTimes(1);
+    const body = postFormSpy.mock.calls[0][1] as { form_data: string };
+    const payload = JSON.parse(body.form_data);
+    expect(payload.result_format).toBe('xlsx');
+    postFormSpy.mockRestore();
+  });
+});
+
 test('should use verbose_map for column headers when available', async () => {
   jest.restoreAllMocks();