[Background search] Return error state when there are no searches (#241411)

## Summary

Closes #240887

Right now if a background search has 0 searches it stays in the "In
progress" state but that's not correct. If no searches are added to the
background search it means that something went wrong. With this PR we
will label as error the search sessions if they have 0 searches after
being created for 30 seconds.

| Before | After |
|--------|------|
| <img width="716" height="89" alt="image"
src="https://github.com/user-attachments/assets/1bb4b60a-20d3-488e-b4e9-9fd8cd4d0b24"
/> | <img width="675" height="88" alt="image"
src="https://github.com/user-attachments/assets/4befb6c0-5edb-4229-9919-e2b76ae90731"
/> |


### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [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
- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)
- [x] Review the [backport
guidelines](https://docs.google.com/document/d/1VyN5k91e5OVumlc0Gb9RPa3h1ewuPE705nRtioPiTvY/edit?usp=sharing)
and apply applicable `backport:*` labels.

Author: AlexGPlay

src/platform/plugins/shared/data/server/search/session/get_session_status.test.ts

@@ -13,6 +13,7 @@ import type { SearchSessionSavedObjectAttributes } from '../../../common';
 import { SearchSessionStatus } from '../../../common';
 import moment from 'moment';
 import type { SearchSessionsConfigSchema } from '../../config';
+import { createSearchSessionSavedObjectAttributesMock } from './mocks';
 
 const mockInProgressSearchResponse = {
   body: {
@@ -46,13 +47,30 @@ describe('getSessionStatus', () => {
   const deps = {
     esClient: elasticsearchServiceMock.createElasticsearchClient(),
   };
-  test("returns an in_progress status if there's nothing inside the session", async () => {
-    const session: any = {
-      idMapping: {},
-      touched: moment(),
-    };
-    expect(await getSessionStatus(deps, session, mockConfig)).toEqual({
-      status: SearchSessionStatus.IN_PROGRESS,
+
+  describe('when there are no searches inside the session', () => {
+    describe('when the search is brand new', () => {
+      test('returns an in_progress status', async () => {
+        const session = createSearchSessionSavedObjectAttributesMock({
+          idMapping: {},
+          created: moment().toISOString(),
+        });
+        expect(await getSessionStatus(deps, session, mockConfig)).toEqual({
+          status: SearchSessionStatus.IN_PROGRESS,
+        });
+      });
+    });
+
+    describe('when the search is has been created for a few seconds', () => {
+      test('returns an error status', async () => {
+        const session = createSearchSessionSavedObjectAttributesMock({
+          idMapping: {},
+          created: moment().subtract(1, 'minutes').toISOString(),
+        });
+        expect(await getSessionStatus(deps, session, mockConfig)).toEqual({
+          status: SearchSessionStatus.ERROR,
+        });
+      });
     });
   });
 

src/platform/plugins/shared/data/server/search/session/get_session_status.ts

@@ -15,6 +15,11 @@ import { SearchStatus } from './types';
 import type { SearchSessionsConfigSchema } from '../../config';
 import { getSearchStatus } from './get_search_status';
 
+// A session should is considered "new" for the first 30 seconds after creation. We need some arbitrary value here
+// because if a sessions stays for too long with no searches assigned to it something happened and we should mark it as error.
+// Some examples of possible issues: the browser is closed or in another tab the search requests are canceled.
+const NEW_SESSION_THRESHOLD_SECONDS = 30;
+
 export async function getSessionStatus(
   deps: { esClient: ElasticsearchClient },
   session: SearchSessionSavedObjectAttributes,
@@ -31,6 +36,13 @@ export async function getSessionStatus(
   }
 
   const searches = Object.values(session.idMapping);
+
+  const secondsSinceCreated = moment().diff(moment(session.created), 'seconds');
+  const isOldSession = secondsSinceCreated > NEW_SESSION_THRESHOLD_SECONDS;
+  if (searches.length === 0 && isOldSession) {
+    return { status: SearchSessionStatus.ERROR };
+  }
+
   const searchStatuses = await Promise.all(
     searches.map(async (s) => {
       const status = await getSearchStatus({

src/platform/plugins/shared/data/server/search/session/mocks.ts

@@ -10,6 +10,7 @@
 import moment from 'moment';
 import type { IScopedSearchSessionsClient } from './types';
 import type { SearchSessionsConfigSchema } from '../../config';
+import type { SearchSessionSavedObjectAttributes } from '../../../common';
 
 export function createSearchSessionsClientMock(): jest.Mocked<IScopedSearchSessionsClient> {
   return {
@@ -33,3 +34,16 @@ export function createSearchSessionsClientMock(): jest.Mocked<IScopedSearchSessi
     ),
   };
 }
+
+export function createSearchSessionSavedObjectAttributesMock(
+  overrides: Partial<SearchSessionSavedObjectAttributes> = {}
+) {
+  return {
+    sessionId: '1234',
+    created: moment().toISOString(),
+    expires: moment().add(7, 'days').toISOString(),
+    idMapping: {},
+    version: '9.2.0',
+    ...overrides,
+  } as SearchSessionSavedObjectAttributes;
+}