fix(tests): prevent jest hangs caused by MessageChannel-mocked React scheduler (#39957)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

superset-frontend/packages/superset-ui-core/src/components/Select/Select.test.tsx

@@ -1160,7 +1160,7 @@ test('does not fire onChange if the same value is selected in single mode', asyn
 
 // Reference for the bug this tests: https://github.com/apache/superset/pull/33043#issuecomment-2809419640
 test('typing and deleting the last character for a new option displays correctly', async () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   render(<Select {...defaultProps} allowNewOptions />);
 
   await open();

superset-frontend/src/SqlLab/components/QueryAutoRefresh/QueryAutoRefresh.test.tsx

@@ -53,7 +53,7 @@ describe('QueryAutoRefresh', () => {
   const refreshApi = 'glob:*/api/v1/query/updated_since?*';
 
   beforeEach(() => {
-    jest.useFakeTimers();
+    jest.useFakeTimers({ advanceTimers: true });
   });
 
   afterEach(() => {

superset-frontend/src/SqlLab/components/SaveDatasetModal/SaveDatasetModal.test.tsx

@@ -45,7 +45,7 @@ fetchMock.get('glob:*/api/v1/dataset/?*', {
   dataset_count: 3,
 });
 
-jest.useFakeTimers();
+jest.useFakeTimers({ advanceTimers: true });
 
 // Mock the user
 const useSelectorMock = jest.spyOn(reactRedux, 'useSelector');

superset-frontend/src/dashboard/components/Header/Header.test.tsx

@@ -611,7 +611,7 @@ test('should refresh the charts', async () => {
 });
 
 test('auto-refresh uses onRefresh with skipped filters and toggles refresh state', async () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   onRefresh.mockResolvedValue(undefined);
 
   const originalRequestAnimationFrame = window.requestAnimationFrame;

superset-frontend/src/dashboard/components/nativeFilters/FilterBar/FilterBar.test.tsx

@@ -39,7 +39,7 @@ import FilterBar from '.';
 import { FILTERS_CONFIG_MODAL_TEST_ID } from '../FiltersConfigModal/FiltersConfigModal';
 import * as dataMaskActions from 'src/dataMask/actions';
 
-jest.useFakeTimers();
+jest.useFakeTimers({ advanceTimers: true });
 
 jest.mock('@superset-ui/core', () => ({
   ...jest.requireActual('@superset-ui/core'),

superset-frontend/src/dashboard/components/nativeFilters/FiltersConfigModal/FiltersConfigForm/FilterScope/__tests__/TreeInitialization.test.tsx

@@ -31,7 +31,7 @@ describe('FilterScope TreeInitialization', () => {
   let formRef: { current: FormInstance | null };
 
   beforeEach(() => {
-    jest.useFakeTimers();
+    jest.useFakeTimers({ advanceTimers: true });
     formRef = { current: null };
   });
 

superset-frontend/src/dashboard/components/nativeFilters/FiltersConfigModal/FiltersConfigForm/FilterScope/__tests__/TreeSelection.test.tsx

@@ -31,7 +31,7 @@ describe('FilterScope TreeSelection', () => {
   let formRef: { current: FormInstance | null };
 
   beforeEach(() => {
-    jest.useFakeTimers();
+    jest.useFakeTimers({ advanceTimers: true });
     formRef = { current: null };
   });
 

superset-frontend/src/dashboard/components/nativeFilters/FiltersConfigModal/FiltersConfigForm/TimeGrainPreFilter.test.tsx

@@ -50,7 +50,7 @@ const TIME_GRAIN_TUPLES: [string, string][] = [
 // "state update on unmounted component" warnings. Scoped fake timers let us
 // clear pending work deterministically during teardown for this test only.
 beforeEach(() => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
 });
 
 afterEach(() => {

superset-frontend/src/explore/components/controls/DateFilterControl/tests/CustomFrame.test.tsx

@@ -28,7 +28,7 @@ import {
 import { CustomFrame } from '../components';
 
 const TODAY = '2024-06-03';
-jest.useFakeTimers();
+jest.useFakeTimers({ advanceTimers: true });
 jest.setSystemTime(new Date(TODAY).getTime());
 
 const emptyValue = '';

superset-frontend/src/explore/components/controls/VizTypeControl/VizTypeControl.test.tsx

@@ -45,7 +45,7 @@ import VizTypeControl, { VIZ_TYPE_CONTROL_TEST_ID } from './index';
 // Mock scrollIntoView to avoid errors in test environment
 jest.mock('scroll-into-view-if-needed', () => jest.fn());
 
-jest.useFakeTimers();
+jest.useFakeTimers({ advanceTimers: true });
 
 class MainPreset extends Preset {
   constructor() {

superset-frontend/src/features/semanticLayers/SemanticLayerModal.test.tsx

@@ -62,7 +62,7 @@ const props = {
 
 beforeEach(() => {
   mockJsonFormsChangeTriggered = false;
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   mockedGet.mockReset();
   mockedPost.mockReset();
 

superset-frontend/src/filters/components/Select/SelectFilterPlugin.test.tsx

@@ -37,7 +37,7 @@ import {
   PluginFilterSelectQueryFormData,
 } from './types';
 
-jest.useFakeTimers();
+jest.useFakeTimers({ advanceTimers: true });
 
 const selectMultipleProps = {
   formData: {
@@ -1286,7 +1286,7 @@ test('resets dependent filter to first item when value does not exist in data',
 });
 
 test('renders text input instead of dropdown when operatorType is ILIKE contains', () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   const setDataMaskMock = jest.fn();
   const props = buildSelectFilterProps({
     formData: { operatorType: SelectFilterOperatorType.Contains },
@@ -1316,7 +1316,7 @@ test('renders text input instead of dropdown when operatorType is ILIKE contains
 });
 
 test('renders text input with starts-with placeholder', () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   const setDataMaskMock = jest.fn();
   const props = buildSelectFilterProps({
     formData: { operatorType: SelectFilterOperatorType.StartsWith },
@@ -1345,7 +1345,7 @@ test('renders text input with starts-with placeholder', () => {
 });
 
 test('typing in LIKE input calls setDataMask with ILIKE Contains payload', async () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   const setDataMaskMock = jest.fn();
   const props = buildSelectFilterProps({
     formData: { operatorType: SelectFilterOperatorType.Contains },
@@ -1391,7 +1391,7 @@ test('typing in LIKE input calls setDataMask with ILIKE Contains payload', async
 });
 
 test('typing in LIKE input with inverse selection calls setDataMask with NOT ILIKE payload', async () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   const setDataMaskMock = jest.fn();
   const props = buildSelectFilterProps({
     formData: {
@@ -1440,7 +1440,7 @@ test('typing in LIKE input with inverse selection calls setDataMask with NOT ILI
 });
 
 test('clear-all resets LIKE input value and calls setDataMask with empty state', async () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   const setDataMaskMock = jest.fn();
   const likeProps = buildSelectFilterProps({
     formData: { operatorType: SelectFilterOperatorType.Contains },
@@ -1506,7 +1506,7 @@ test('clear-all resets LIKE input value and calls setDataMask with empty state',
 });
 
 test('pending LIKE debounce still applies after rerender recreates updateDataMask', async () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   const setDataMaskMock = jest.fn();
   const likeProps = buildSelectFilterProps({
     formData: { operatorType: SelectFilterOperatorType.Contains },
@@ -1573,7 +1573,7 @@ test('pending LIKE debounce still applies after rerender recreates updateDataMas
 });
 
 test('pending LIKE debounce is canceled when operatorType switches back to Exact', async () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   const setDataMaskMock = jest.fn();
   const likeProps = buildSelectFilterProps({
     formData: { operatorType: SelectFilterOperatorType.Contains },
@@ -1628,7 +1628,7 @@ test('pending LIKE debounce is canceled when operatorType switches back to Exact
 });
 
 test('renders standard Select dropdown when operatorType is Exact', () => {
-  jest.useFakeTimers();
+  jest.useFakeTimers({ advanceTimers: true });
   const setDataMaskMock = jest.fn();
   const props = buildSelectFilterProps({
     formData: { operatorType: SelectFilterOperatorType.Exact },

superset-frontend/src/pages/DatasetList/DatasetList.test.tsx

@@ -42,15 +42,16 @@ beforeEach(() => {
 });
 
 afterEach(async () => {
+  // Restore real timers FIRST so the flush below uses real setTimeout,
+  // preventing a deadlock if a test threw while fake timers were active.
+  jest.useRealTimers();
+
   // Flush pending React state updates within act() to prevent warnings
   // and "document global undefined" errors from async operations
   await act(async () => {
     await new Promise(resolve => setTimeout(resolve, 0));
   });
 
-  // Restore real timers in case a test using fake timers threw early
-  jest.useRealTimers();
-
   // Reset browser history state to prevent query params leaking between tests
   window.history.replaceState({}, '', '/');
 

superset-frontend/src/pages/FileHandler/index.test.tsx

@@ -115,6 +115,12 @@ type LaunchQueue = {
   ) => void;
 };
 
+const pendingTimerIds = new Set<ReturnType<typeof setTimeout>>();
+const MAX_CONSUMER_POLL_ATTEMPTS = 50;
+
+// Defer the consumer call to a macrotask so it doesn't fire synchronously inside
+// the component's useEffect — calling it inline deadlocks Jest because the
+// MessageChannel mock in jsDomWithFetchAPI forces React to schedule via setTimeout.
 const setupLaunchQueue = (fileHandle: MockFileHandle | null = null) => {
   let savedConsumer:
     | ((params: { files?: MockFileHandle[] }) => void | Promise<void>)
@@ -123,7 +129,11 @@ const setupLaunchQueue = (fileHandle: MockFileHandle | null = null) => {
     setConsumer: (consumer: (params: { files?: MockFileHandle[] }) => void) => {
       savedConsumer = consumer;
       if (fileHandle) {
-        consumer({ files: [fileHandle] });
+        const id = setTimeout(() => {
+          pendingTimerIds.delete(id);
+          consumer({ files: [fileHandle] });
+        }, 0);
+        pendingTimerIds.add(id);
       }
     },
   };
@@ -132,25 +142,34 @@ const setupLaunchQueue = (fileHandle: MockFileHandle | null = null) => {
       // In slower CI runners, useEffect may not have registered the consumer yet.
       // Wait briefly for it before triggering.
       let attempts = 0;
-      while (!savedConsumer && attempts < 50) {
+      while (!savedConsumer && attempts < MAX_CONSUMER_POLL_ATTEMPTS) {
         // eslint-disable-next-line no-await-in-loop
         await new Promise(resolve => {
           setTimeout(resolve, 0);
         });
         attempts += 1;
       }
-      await savedConsumer?.(params);
+      if (!savedConsumer) {
+        throw new Error(
+          `LaunchQueue consumer was never registered after ${MAX_CONSUMER_POLL_ATTEMPTS} polling attempts`,
+        );
+      }
+      await savedConsumer(params);
     },
   };
 };
 
 beforeEach(() => {
   jest.clearAllMocks();
-  delete (window as any).launchQueue;
+  delete (window as unknown as Window & { launchQueue?: LaunchQueue })
+    .launchQueue;
 });
 
 afterEach(() => {
-  delete (window as any).launchQueue;
+  pendingTimerIds.forEach(id => clearTimeout(id));
+  pendingTimerIds.clear();
+  delete (window as unknown as Window & { launchQueue?: LaunchQueue })
+    .launchQueue;
 });
 
 test('shows error when launchQueue is not supported', async () => {