[data.search] Fix unhandled promise rejections (#181785)

## Summary

Resolves https://github.com/elastic/kibana/issues/168957.

It turns out the underlying issue was resolved in
https://github.com/elastic/kibana/pull/170041 (unhandled errors when
deleting not being handled). However this still left it up to consumers
of `pollSearch` to be 100% sure they weren't leaking unhandled promise
rejections. This adds code directly to `pollSearch` that will handle
rejections if they aren't handled in the calling code. It also adds
tests to consumers of `pollSearch` to make sure they don't barf in the
case that the `cancel` function errors.

### Checklist

- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

src/plugins/data/common/search/poll_search.test.ts

@@ -85,6 +85,25 @@ describe('pollSearch', () => {
     expect(cancelFn).toBeCalledTimes(1);
   });
 
+  test('Does not leak unresolved promises on cancel', async () => {
+    const searchFn = getMockedSearch$(20);
+    const cancelFn = jest.fn().mockRejectedValueOnce({ error: 'Oh no!' });
+    const abortController = new AbortController();
+    const poll = pollSearch(searchFn, cancelFn, {
+      abortSignal: abortController.signal,
+    }).toPromise();
+
+    await new Promise((resolve) => setTimeout(resolve, 300));
+    abortController.abort();
+
+    await expect(poll).rejects.toThrow(AbortError);
+
+    await new Promise((resolve) => setTimeout(resolve, 1000));
+
+    expect(searchFn).toBeCalledTimes(1);
+    expect(cancelFn).toBeCalledTimes(1);
+  });
+
   test("Stops, but doesn't cancel on unsubscribe", async () => {
     const searchFn = getMockedSearch$(20);
     const cancelFn = jest.fn();

src/plugins/data/common/search/poll_search.ts

@@ -14,7 +14,7 @@ import { isAbortResponse, isRunningResponse } from '..';
 
 export const pollSearch = <Response extends IKibanaSearchResponse>(
   search: () => Promise<Response>,
-  cancel?: () => void,
+  cancel?: () => Promise<void>,
   { pollInterval, abortSignal }: IAsyncSearchOptions = {}
 ): Observable<Response> => {
   const getPollInterval = (elapsedTime: number): number => {
@@ -41,8 +41,13 @@ export const pollSearch = <Response extends IKibanaSearchResponse>(
       throw new AbortError();
     }
 
+    const safeCancel = () =>
+      cancel?.().catch((e) => {
+        console.error(e); // eslint-disable-line no-console
+      });
+
     if (cancel) {
-      abortSignal?.addEventListener('abort', cancel, { once: true });
+      abortSignal?.addEventListener('abort', safeCancel, { once: true });
     }
 
     const aborted$ = (abortSignal ? fromEvent(abortSignal, 'abort') : EMPTY).pipe(

src/plugins/data/public/search/search_interceptor/search_interceptor.test.ts

@@ -500,6 +500,50 @@ describe('SearchInterceptor', () => {
       expect(mockCoreSetup.http.delete).toHaveBeenCalledTimes(1);
     });
 
+    test('should not leak unresolved promises if DELETE fails', async () => {
+      mockCoreSetup.http.delete.mockRejectedValueOnce({ status: 404, statusText: 'Not Found' });
+      const responses = [
+        {
+          time: 10,
+          value: {
+            isPartial: true,
+            isRunning: true,
+            rawResponse: {},
+            id: 1,
+          },
+        },
+        {
+          time: 10,
+          value: {
+            statusCode: 500,
+            message: 'oh no',
+            id: 1,
+          },
+          isError: true,
+        },
+      ];
+      mockFetchImplementation(responses);
+
+      const response = searchInterceptor.search({}, { pollInterval: 0 });
+      response.subscribe({ next, error });
+
+      await timeTravel(10);
+
+      expect(next).toHaveBeenCalled();
+      expect(error).not.toHaveBeenCalled();
+      expect(fetchMock).toHaveBeenCalled();
+      expect(mockCoreSetup.http.delete).not.toHaveBeenCalled();
+
+      // Long enough to reach the timeout but not long enough to reach the next response
+      await timeTravel(10);
+
+      expect(error).toHaveBeenCalled();
+      expect(error.mock.calls[0][0]).toBeInstanceOf(Error);
+      expect((error.mock.calls[0][0] as Error).message).toBe('oh no');
+      expect(fetchMock).toHaveBeenCalledTimes(2);
+      expect(mockCoreSetup.http.delete).toHaveBeenCalledTimes(1);
+    });
+
     test('should NOT DELETE a running SAVED async search on abort', async () => {
       const sessionId = 'sessionId';
       sessionService.isCurrentSession.mockImplementation((_sessionId) => _sessionId === sessionId);

src/plugins/data/public/search/search_interceptor/search_interceptor.ts

@@ -339,11 +339,19 @@ export class SearchInterceptor {
           isSavedToBackground = true;
         });
 
-    const sendCancelRequest = once(() => {
-      this.deps.http.delete(`/internal/search/${strategy}/${id}`, { version: '1' });
-    });
+    const sendCancelRequest = once(() =>
+      this.deps.http.delete(`/internal/search/${strategy}/${id}`, { version: '1' })
+    );
 
-    const cancel = () => id && !isSavedToBackground && sendCancelRequest();
+    const cancel = async () => {
+      if (!id || isSavedToBackground) return;
+      try {
+        await sendCancelRequest();
+      } catch (e) {
+        // eslint-disable-next-line no-console
+        console.error(e);
+      }
+    };
 
     // Async search requires a series of requests
     // 1) POST /<index pattern>/_async_search/

src/plugins/data/server/search/strategies/ese_search/ese_search_strategy.test.ts

@@ -66,7 +66,8 @@ describe('ES search strategy', () => {
   const mockSubmitCaller = jest.fn();
   const mockDeleteCaller = jest.fn();
   const mockLogger: any = {
-    debug: () => {},
+    debug: jest.fn(),
+    error: jest.fn(),
   };
   const mockDeps = {
     uiSettingsClient: {
@@ -357,6 +358,47 @@ describe('ES search strategy', () => {
         expect(err).not.toBeUndefined();
         expect(mockDeleteCaller).toBeCalled();
       });
+
+      it('should not throw when encountering an error deleting', async () => {
+        mockSubmitCaller.mockResolvedValueOnce({
+          ...mockAsyncResponse,
+          body: {
+            ...mockAsyncResponse.body,
+            is_running: true,
+          },
+        });
+
+        const errResponse = new errors.ResponseError({
+          body: xContentParseException,
+          statusCode: 400,
+          headers: {},
+          warnings: [],
+          meta: {} as any,
+        });
+        mockDeleteCaller.mockRejectedValueOnce(errResponse);
+
+        const params = { index: 'logstash-*', body: { query: {} } };
+        const esSearch = await enhancedEsSearchStrategyProvider(
+          mockLegacyConfig$,
+          mockSearchConfig,
+          mockLogger
+        );
+        const abortController = new AbortController();
+        const abortSignal = abortController.signal;
+
+        // Abort after an incomplete first response is returned
+        setTimeout(() => abortController.abort(), 100);
+
+        let err: KbnServerError | undefined;
+        try {
+          await esSearch.search({ params }, { abortSignal }, mockDeps).toPromise();
+        } catch (e) {
+          err = e;
+        }
+        expect(mockSubmitCaller).toBeCalled();
+        expect(err).not.toBeUndefined();
+        expect(mockDeleteCaller).toBeCalled();
+      });
     });
 
     describe('with sessionId', () => {