[Search Sessions] Improve session restoration back button (#87635)

docs/development/plugins/kibana_utils/public/state_sync/kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.cancel.md

@@ -1,13 +0,0 @@
-<!-- Do not edit this file. It is automatically generated by API Documenter. -->
-
-[Home](./index.md) &gt; [kibana-plugin-plugins-kibana\_utils-public-state\_sync](./kibana-plugin-plugins-kibana_utils-public-state_sync.md) &gt; [IKbnUrlStateStorage](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.md) &gt; [cancel](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.cancel.md)
-
-## IKbnUrlStateStorage.cancel property
-
-cancels any pending url updates
-
-<b>Signature:</b>
-
-```typescript
-cancel: () => void;
-```

docs/development/plugins/kibana_utils/public/state_sync/kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.flush.md

@@ -1,15 +0,0 @@
-<!-- Do not edit this file. It is automatically generated by API Documenter. -->
-
-[Home](./index.md) &gt; [kibana-plugin-plugins-kibana\_utils-public-state\_sync](./kibana-plugin-plugins-kibana_utils-public-state_sync.md) &gt; [IKbnUrlStateStorage](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.md) &gt; [flush](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.flush.md)
-
-## IKbnUrlStateStorage.flush property
-
-Synchronously runs any pending url updates, returned boolean indicates if change occurred.
-
-<b>Signature:</b>
-
-```typescript
-flush: (opts?: {
-        replace?: boolean;
-    }) => boolean;
-```

docs/development/plugins/kibana_utils/public/state_sync/kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.kbnurlcontrols.md

@@ -0,0 +1,13 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-plugins-kibana\_utils-public-state\_sync](./kibana-plugin-plugins-kibana_utils-public-state_sync.md) &gt; [IKbnUrlStateStorage](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.md) &gt; [kbnUrlControls](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.kbnurlcontrols.md)
+
+## IKbnUrlStateStorage.kbnUrlControls property
+
+Lower level wrapper around history library that handles batching multiple URL updates into one history change
+
+<b>Signature:</b>
+
+```typescript
+kbnUrlControls: IKbnUrlControls;
+```

docs/development/plugins/kibana_utils/public/state_sync/kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.md

@@ -20,9 +20,8 @@ export interface IKbnUrlStateStorage extends IStateStorage
 
 |  Property | Type | Description |
 |  --- | --- | --- |
-|  [cancel](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.cancel.md) | <code>() =&gt; void</code> | cancels any pending url updates |
 |  [change$](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.change_.md) | <code>&lt;State = unknown&gt;(key: string) =&gt; Observable&lt;State &#124; null&gt;</code> |  |
-|  [flush](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.flush.md) | <code>(opts?: {</code><br/><code>        replace?: boolean;</code><br/><code>    }) =&gt; boolean</code> | Synchronously runs any pending url updates, returned boolean indicates if change occurred. |
 |  [get](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.get.md) | <code>&lt;State = unknown&gt;(key: string) =&gt; State &#124; null</code> |  |
+|  [kbnUrlControls](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.kbnurlcontrols.md) | <code>IKbnUrlControls</code> | Lower level wrapper around history library that handles batching multiple URL updates into one history change |
 |  [set](./kibana-plugin-plugins-kibana_utils-public-state_sync.ikbnurlstatestorage.set.md) | <code>&lt;State&gt;(key: string, state: State, opts?: {</code><br/><code>        replace: boolean;</code><br/><code>    }) =&gt; Promise&lt;string &#124; undefined&gt;</code> |  |
 

src/plugins/dashboard/public/application/dashboard_app.tsx

@@ -6,22 +6,22 @@
  * Public License, v 1.
  */
 
-import _ from 'lodash';
 import { History } from 'history';
-import { merge, Subscription } from 'rxjs';
-import React, { useEffect, useCallback, useState } from 'react';
+import { merge, Subject, Subscription } from 'rxjs';
+import React, { useCallback, useEffect, useMemo, useState } from 'react';
 
+import { debounceTime, tap } from 'rxjs/operators';
 import { useKibana } from '../../../kibana_react/public';
 import { DashboardConstants } from '../dashboard_constants';
 import { DashboardTopNav } from './top_nav/dashboard_top_nav';
 import { DashboardAppServices, DashboardEmbedSettings, DashboardRedirect } from './types';
 import {
+  getChangesFromAppStateForContainerState,
+  getDashboardContainerInput,
+  getFiltersSubscription,
   getInputSubscription,
   getOutputSubscription,
-  getFiltersSubscription,
   getSearchSessionIdFromURL,
-  getDashboardContainerInput,
-  getChangesFromAppStateForContainerState,
 } from './dashboard_app_functions';
 import {
   useDashboardBreadcrumbs,
@@ -30,11 +30,11 @@ import {
   useSavedDashboard,
 } from './hooks';
 
-import { removeQueryParam } from '../services/kibana_utils';
 import { IndexPattern } from '../services/data';
 import { EmbeddableRenderer } from '../services/embeddable';
 import { DashboardContainerInput } from '.';
 import { leaveConfirmStrings } from '../dashboard_strings';
+import { createQueryParamObservable, replaceUrlHashQuery } from '../../../kibana_utils/public';
 
 export interface DashboardAppProps {
   history: History;
@@ -59,7 +59,7 @@ export function DashboardApp({
     indexPatterns: indexPatternService,
   } = useKibana<DashboardAppServices>().services;
 
-  const [lastReloadTime, setLastReloadTime] = useState(0);
+  const triggerRefresh$ = useMemo(() => new Subject<{ force?: boolean }>(), []);
   const [indexPatterns, setIndexPatterns] = useState<IndexPattern[]>([]);
 
   const savedDashboard = useSavedDashboard(savedDashboardId, history);
@@ -68,9 +68,13 @@ export function DashboardApp({
     history
   );
   const dashboardContainer = useDashboardContainer(dashboardStateManager, history, false);
+  const searchSessionIdQuery$ = useMemo(
+    () => createQueryParamObservable(history, DashboardConstants.SEARCH_SESSION_ID),
+    [history]
+  );
 
   const refreshDashboardContainer = useCallback(
-    (lastReloadRequestTime?: number) => {
+    (force?: boolean) => {
       if (!dashboardContainer || !dashboardStateManager) {
         return;
       }
@@ -80,7 +84,7 @@ export function DashboardApp({
         appStateDashboardInput: getDashboardContainerInput({
           isEmbeddedExternally: Boolean(embedSettings),
           dashboardStateManager,
-          lastReloadRequestTime,
+          lastReloadRequestTime: force ? Date.now() : undefined,
           dashboardCapabilities,
           query: data.query,
         }),
@@ -100,10 +104,35 @@ export function DashboardApp({
         const shouldRefetch = Object.keys(changes).some(
           (changeKey) => !noRefetchKeys.includes(changeKey as keyof DashboardContainerInput)
         );
-        if (getSearchSessionIdFromURL(history)) {
-          // going away from a background search results
-          removeQueryParam(history, DashboardConstants.SEARCH_SESSION_ID, true);
-        }
+
+        const newSearchSessionId: string | undefined = (() => {
+          // do not update session id if this is irrelevant state change to prevent excessive searches
+          if (!shouldRefetch) return;
+
+          let searchSessionIdFromURL = getSearchSessionIdFromURL(history);
+          if (searchSessionIdFromURL) {
+            if (
+              data.search.session.isRestore() &&
+              data.search.session.isCurrentSession(searchSessionIdFromURL)
+            ) {
+              // navigating away from a restored session
+              dashboardStateManager.kbnUrlStateStorage.kbnUrlControls.updateAsync((nextUrl) => {
+                if (nextUrl.includes(DashboardConstants.SEARCH_SESSION_ID)) {
+                  return replaceUrlHashQuery(nextUrl, (query) => {
+                    delete query[DashboardConstants.SEARCH_SESSION_ID];
+                    return query;
+                  });
+                }
+                return nextUrl;
+              });
+              searchSessionIdFromURL = undefined;
+            } else {
+              data.search.session.restore(searchSessionIdFromURL);
+            }
+          }
+
+          return searchSessionIdFromURL ?? data.search.session.start();
+        })();
 
         if (changes.viewMode) {
           setViewMode(changes.viewMode);
@@ -111,8 +140,7 @@ export function DashboardApp({
 
         dashboardContainer.updateInput({
           ...changes,
-          // do not start a new session if this is irrelevant state change to prevent excessive searches
-          ...(shouldRefetch && { searchSessionId: data.search.session.start() }),
+          ...(newSearchSessionId && { searchSessionId: newSearchSessionId }),
         });
       }
     },
@@ -159,23 +187,42 @@ export function DashboardApp({
     subscriptions.add(
       merge(
         ...[timeFilter.getRefreshIntervalUpdate$(), timeFilter.getTimeUpdate$()]
-      ).subscribe(() => refreshDashboardContainer())
+      ).subscribe(() => triggerRefresh$.next())
     );
+
     subscriptions.add(
       merge(
         data.search.session.onRefresh$,
-        data.query.timefilter.timefilter.getAutoRefreshFetch$()
+        data.query.timefilter.timefilter.getAutoRefreshFetch$(),
+        searchSessionIdQuery$
       ).subscribe(() => {
-        setLastReloadTime(() => new Date().getTime());
+        triggerRefresh$.next({ force: true });
       })
     );
 
     dashboardStateManager.registerChangeListener(() => {
       // we aren't checking dirty state because there are changes the container needs to know about
       // that won't make the dashboard "dirty" - like a view mode change.
-      refreshDashboardContainer();
+      triggerRefresh$.next();
     });
 
+    // debounce `refreshDashboardContainer()`
+    // use `forceRefresh=true` in case at least one debounced trigger asked for it
+    let forceRefresh: boolean = false;
+    subscriptions.add(
+      triggerRefresh$
+        .pipe(
+          tap((trigger) => {
+            forceRefresh = forceRefresh || (trigger?.force ?? false);
+          }),
+          debounceTime(50)
+        )
+        .subscribe(() => {
+          refreshDashboardContainer(forceRefresh);
+          forceRefresh = false;
+        })
+    );
+
     return () => {
       subscriptions.unsubscribe();
     };
@@ -187,6 +234,8 @@ export function DashboardApp({
     data.search.session,
     indexPatternService,
     dashboardStateManager,
+    searchSessionIdQuery$,
+    triggerRefresh$,
     refreshDashboardContainer,
   ]);
 
@@ -216,11 +265,6 @@ export function DashboardApp({
     };
   }, [dashboardStateManager, dashboardContainer, onAppLeave, embeddable]);
 
-  // Refresh the dashboard container when lastReloadTime changes
-  useEffect(() => {
-    refreshDashboardContainer(lastReloadTime);
-  }, [lastReloadTime, refreshDashboardContainer]);
-
   return (
     <div className="app-container dshAppContainer">
       {savedDashboard && dashboardStateManager && dashboardContainer && viewMode && (
@@ -242,7 +286,7 @@ export function DashboardApp({
                 // The user can still request a reload in the query bar, even if the
                 // query is the same, and in that case, we have to explicitly ask for
                 // a reload, since no state changes will cause it.
-                setLastReloadTime(() => new Date().getTime());
+                triggerRefresh$.next({ force: true });
               }
             }}
           />

src/plugins/dashboard/public/application/dashboard_state_manager.ts

@@ -72,7 +72,7 @@ export class DashboardStateManager {
   >;
   private readonly stateContainerChangeSub: Subscription;
   private readonly STATE_STORAGE_KEY = '_a';
-  private readonly kbnUrlStateStorage: IKbnUrlStateStorage;
+  public readonly kbnUrlStateStorage: IKbnUrlStateStorage;
   private readonly stateSyncRef: ISyncStateRef;
   private readonly history: History;
   private readonly usageCollection: UsageCollectionSetup | undefined;
@@ -596,7 +596,7 @@ export class DashboardStateManager {
       this.toUrlState(this.stateContainer.get())
     );
     // immediately forces scheduled updates and changes location
-    return this.kbnUrlStateStorage.flush({ replace });
+    return !!this.kbnUrlStateStorage.kbnUrlControls.flush(replace);
   }
 
   // TODO: find nicer solution for this

src/plugins/dashboard/public/application/listing/__snapshots__/dashboard_listing.test.tsx.snap

@@ -4,10 +4,16 @@ exports[`after fetch When given a title that matches multiple dashboards, filter
 <DashboardListing
   kbnUrlStateStorage={
     Object {
-      "cancel": [Function],
       "change$": [Function],
-      "flush": [Function],
       "get": [Function],
+      "kbnUrlControls": Object {
+        "cancel": [Function],
+        "flush": [Function],
+        "getPendingUrl": [Function],
+        "listen": [Function],
+        "update": [Function],
+        "updateAsync": [Function],
+      },
       "set": [Function],
     }
   }
@@ -144,10 +150,16 @@ exports[`after fetch hideWriteControls 1`] = `
 <DashboardListing
   kbnUrlStateStorage={
     Object {
-      "cancel": [Function],
       "change$": [Function],
-      "flush": [Function],
       "get": [Function],
+      "kbnUrlControls": Object {
+        "cancel": [Function],
+        "flush": [Function],
+        "getPendingUrl": [Function],
+        "listen": [Function],
+        "update": [Function],
+        "updateAsync": [Function],
+      },
       "set": [Function],
     }
   }
@@ -237,10 +249,16 @@ exports[`after fetch initialFilter 1`] = `
   initialFilter="testFilter"
   kbnUrlStateStorage={
     Object {
-      "cancel": [Function],
       "change$": [Function],
-      "flush": [Function],
       "get": [Function],
+      "kbnUrlControls": Object {
+        "cancel": [Function],
+        "flush": [Function],
+        "getPendingUrl": [Function],
+        "listen": [Function],
+        "update": [Function],
+        "updateAsync": [Function],
+      },
       "set": [Function],
     }
   }
@@ -376,10 +394,16 @@ exports[`after fetch renders all table rows 1`] = `
 <DashboardListing
   kbnUrlStateStorage={
     Object {
-      "cancel": [Function],
       "change$": [Function],
-      "flush": [Function],
       "get": [Function],
+      "kbnUrlControls": Object {
+        "cancel": [Function],
+        "flush": [Function],
+        "getPendingUrl": [Function],
+        "listen": [Function],
+        "update": [Function],
+        "updateAsync": [Function],
+      },
       "set": [Function],
     }
   }
@@ -515,10 +539,16 @@ exports[`after fetch renders call to action when no dashboards exist 1`] = `
 <DashboardListing
   kbnUrlStateStorage={
     Object {
-      "cancel": [Function],
       "change$": [Function],
-      "flush": [Function],
       "get": [Function],
+      "kbnUrlControls": Object {
+        "cancel": [Function],
+        "flush": [Function],
+        "getPendingUrl": [Function],
+        "listen": [Function],
+        "update": [Function],
+        "updateAsync": [Function],
+      },
       "set": [Function],
     }
   }
@@ -654,10 +684,16 @@ exports[`after fetch renders warning when listingLimit is exceeded 1`] = `
 <DashboardListing
   kbnUrlStateStorage={
     Object {
-      "cancel": [Function],
       "change$": [Function],
-      "flush": [Function],
       "get": [Function],
+      "kbnUrlControls": Object {
+        "cancel": [Function],
+        "flush": [Function],
+        "getPendingUrl": [Function],
+        "listen": [Function],
+        "update": [Function],
+        "updateAsync": [Function],
+      },
       "set": [Function],
     }
   }

src/plugins/data/public/query/state_sync/sync_state_with_url.test.ts

@@ -90,7 +90,7 @@ describe('sync_query_state_with_url', () => {
   test('url is actually changed when data in services changes', () => {
     const { stop } = syncQueryStateWithUrl(queryServiceStart, kbnUrlStateStorage);
     filterManager.setFilters([gF, aF]);
-    kbnUrlStateStorage.flush(); // sync force location change
+    kbnUrlStateStorage.kbnUrlControls.flush(); // sync force location change
     expect(history.location.hash).toMatchInlineSnapshot(
       `"#?_g=(filters:!(('$state':(store:globalState),meta:(alias:!n,disabled:!t,index:'logstash-*',key:query,negate:!t,type:custom,value:'%7B%22match%22:%7B%22key1%22:%22value1%22%7D%7D'),query:(match:(key1:value1)))),refreshInterval:(pause:!t,value:0),time:(from:now-15m,to:now))"`
     );
@@ -126,7 +126,7 @@ describe('sync_query_state_with_url', () => {
 
   test('when url is changed, filters synced back to filterManager', () => {
     const { stop } = syncQueryStateWithUrl(queryServiceStart, kbnUrlStateStorage);
-    kbnUrlStateStorage.cancel(); // stop initial syncing pending update
+    kbnUrlStateStorage.kbnUrlControls.cancel(); // stop initial syncing pending update
     history.push(pathWithFilter);
     expect(filterManager.getGlobalFilters()).toHaveLength(1);
     stop();

src/plugins/discover/public/application/angular/context_state.ts

@@ -206,7 +206,7 @@ export function getState({
       }
     },
     // helper function just needed for testing
-    flushToUrl: (replace?: boolean) => stateStorage.flush({ replace }),
+    flushToUrl: (replace?: boolean) => stateStorage.kbnUrlControls.flush(replace),
   };
 }
 

src/plugins/discover/public/application/angular/discover.js

@@ -47,8 +47,6 @@ import { popularizeField } from '../helpers/popularize_field';
 import { getSwitchIndexPatternAppState } from '../helpers/get_switch_index_pattern_app_state';
 import { addFatalError } from '../../../../kibana_legacy/public';
 import { METRIC_TYPE } from '@kbn/analytics';
-import { SEARCH_SESSION_ID_QUERY_PARAM } from '../../url_generator';
-import { getQueryParams, removeQueryParam } from '../../../../kibana_utils/public';
 import {
   DEFAULT_COLUMNS_SETTING,
   MODIFY_COLUMNS_ON_SWITCH,
@@ -62,6 +60,7 @@ import { getTopNavLinks } from '../components/top_nav/get_top_nav_links';
 import { updateSearchSource } from '../helpers/update_search_source';
 import { calcFieldCounts } from '../helpers/calc_field_counts';
 import { getDefaultSort } from './doc_table/lib/get_default_sort';
+import { DiscoverSearchSessionManager } from './discover_search_session';
 
 const services = getServices();
 
@@ -86,9 +85,6 @@ const fetchStatuses = {
   ERROR: 'error',
 };
 
-const getSearchSessionIdFromURL = (history) =>
-  getQueryParams(history.location)[SEARCH_SESSION_ID_QUERY_PARAM];
-
 const app = getAngularModule();
 
 app.config(($routeProvider) => {
@@ -177,7 +173,9 @@ function discoverController($route, $scope, Promise) {
   const { isDefault: isDefaultType } = indexPatternsUtils;
   const subscriptions = new Subscription();
   const refetch$ = new Subject();
+
   let inspectorRequest;
+  let isChangingIndexPattern = false;
   const savedSearch = $route.current.locals.savedObjects.savedSearch;
   $scope.searchSource = savedSearch.searchSource;
   $scope.indexPattern = resolveIndexPattern(
@@ -195,15 +193,10 @@ function discoverController($route, $scope, Promise) {
   };
 
   const history = getHistory();
-  // used for restoring a search session
-  let isInitialSearch = true;
-
-  // search session requested a data refresh
-  subscriptions.add(
-    data.search.session.onRefresh$.subscribe(() => {
-      refetch$.next();
-    })
-  );
+  const searchSessionManager = new DiscoverSearchSessionManager({
+    history,
+    session: data.search.session,
+  });
 
   const state = getState({
     getStateDefaults,
@@ -255,6 +248,7 @@ function discoverController($route, $scope, Promise) {
       $scope.$evalAsync(async () => {
         if (oldStatePartial.index !== newStatePartial.index) {
           //in case of index pattern switch the route has currently to be reloaded, legacy
+          isChangingIndexPattern = true;
           $route.reload();
           return;
         }
@@ -351,7 +345,12 @@ function discoverController($route, $scope, Promise) {
     if (abortController) abortController.abort();
     savedSearch.destroy();
     subscriptions.unsubscribe();
-    data.search.session.clear();
+    if (!isChangingIndexPattern) {
+      // HACK:
+      // do not clear session when changing index pattern due to how state management around it is setup
+      // it will be cleared by searchSessionManager on controller reload instead
+      data.search.session.clear();
+    }
     appStateUnsubscribe();
     stopStateSync();
     stopSyncingGlobalStateWithUrl();
@@ -475,7 +474,8 @@ function discoverController($route, $scope, Promise) {
     return (
       config.get(SEARCH_ON_PAGE_LOAD_SETTING) ||
       savedSearch.id !== undefined ||
-      timefilter.getRefreshInterval().pause === false
+      timefilter.getRefreshInterval().pause === false ||
+      searchSessionManager.hasSearchSessionIdInURL()
     );
   };
 
@@ -486,7 +486,8 @@ function discoverController($route, $scope, Promise) {
         filterManager.getFetches$(),
         timefilter.getFetch$(),
         timefilter.getAutoRefreshFetch$(),
-        data.query.queryString.getUpdates$()
+        data.query.queryString.getUpdates$(),
+        searchSessionManager.newSearchSessionIdFromURL$
       ).pipe(debounceTime(100));
 
       subscriptions.add(
@@ -512,6 +513,13 @@ function discoverController($route, $scope, Promise) {
         )
       );
 
+      subscriptions.add(
+        data.search.session.onRefresh$.subscribe(() => {
+          searchSessionManager.removeSearchSessionIdFromURL({ replace: false });
+          refetch$.next();
+        })
+      );
+
       $scope.changeInterval = (interval) => {
         if (interval) {
           setAppState({ interval });
@@ -591,20 +599,7 @@ function discoverController($route, $scope, Promise) {
     if (abortController) abortController.abort();
     abortController = new AbortController();
 
-    const searchSessionId = (() => {
-      const searchSessionIdFromURL = getSearchSessionIdFromURL(history);
-      if (searchSessionIdFromURL) {
-        if (isInitialSearch) {
-          data.search.session.restore(searchSessionIdFromURL);
-          isInitialSearch = false;
-          return searchSessionIdFromURL;
-        } else {
-          // navigating away from background search
-          removeQueryParam(history, SEARCH_SESSION_ID_QUERY_PARAM);
-        }
-      }
-      return data.search.session.start();
-    })();
+    const searchSessionId = searchSessionManager.getNextSearchSessionId();
 
     $scope
       .updateDataSource()
@@ -631,6 +626,7 @@ function discoverController($route, $scope, Promise) {
 
   $scope.handleRefresh = function (_payload, isUpdate) {
     if (isUpdate === false) {
+      searchSessionManager.removeSearchSessionIdFromURL({ replace: false });
       refetch$.next();
     }
   };

src/plugins/discover/public/application/angular/discover_search_session.test.ts

@@ -0,0 +1,96 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * and the Server Side Public License, v 1; you may not use this file except in
+ * compliance with, at your election, the Elastic License or the Server Side
+ * Public License, v 1.
+ */
+
+import { DiscoverSearchSessionManager } from './discover_search_session';
+import { createMemoryHistory } from 'history';
+import { dataPluginMock } from '../../../../data/public/mocks';
+import { DataPublicPluginStart } from '../../../../data/public';
+
+describe('DiscoverSearchSessionManager', () => {
+  const history = createMemoryHistory();
+  const session = dataPluginMock.createStartContract().search.session as jest.Mocked<
+    DataPublicPluginStart['search']['session']
+  >;
+  const searchSessionManager = new DiscoverSearchSessionManager({
+    history,
+    session,
+  });
+
+  beforeEach(() => {
+    history.push('/');
+    session.start.mockReset();
+    session.restore.mockReset();
+    session.getSessionId.mockReset();
+    session.isCurrentSession.mockReset();
+    session.isRestore.mockReset();
+  });
+
+  describe('getNextSearchSessionId', () => {
+    test('starts a new session', () => {
+      const nextId = 'id';
+      session.start.mockImplementationOnce(() => nextId);
+
+      const id = searchSessionManager.getNextSearchSessionId();
+      expect(id).toEqual(nextId);
+      expect(session.start).toBeCalled();
+    });
+
+    test('restores a session using query param from the URL', () => {
+      const nextId = 'id_from_url';
+      history.push(`/?searchSessionId=${nextId}`);
+
+      const id = searchSessionManager.getNextSearchSessionId();
+      expect(id).toEqual(nextId);
+      expect(session.restore).toBeCalled();
+    });
+
+    test('removes query param from the URL when navigating away from a restored session', () => {
+      const idFromUrl = 'id_from_url';
+      history.push(`/?searchSessionId=${idFromUrl}`);
+
+      const nextId = 'id';
+      session.start.mockImplementationOnce(() => nextId);
+      session.isCurrentSession.mockImplementationOnce(() => true);
+      session.isRestore.mockImplementationOnce(() => true);
+
+      const id = searchSessionManager.getNextSearchSessionId();
+      expect(id).toEqual(nextId);
+      expect(session.start).toBeCalled();
+      expect(history.location.search).toMatchInlineSnapshot(`""`);
+    });
+  });
+
+  describe('newSearchSessionIdFromURL$', () => {
+    test('notifies about searchSessionId changes in the URL', () => {
+      const emits: Array<string | null> = [];
+
+      const sub = searchSessionManager.newSearchSessionIdFromURL$.subscribe((newId) => {
+        emits.push(newId);
+      });
+
+      history.push(`/?searchSessionId=id1`);
+      history.push(`/?searchSessionId=id1`);
+      session.isCurrentSession.mockImplementationOnce(() => true);
+      history.replace(`/?searchSessionId=id2`); // should skip current this
+      history.replace(`/`);
+      history.push(`/?searchSessionId=id1`);
+      history.push(`/`);
+
+      expect(emits).toMatchInlineSnapshot(`
+        Array [
+          "id1",
+          null,
+          "id1",
+          null,
+        ]
+      `);
+
+      sub.unsubscribe();
+    });
+  });
+});

src/plugins/discover/public/application/angular/discover_search_session.ts

@@ -0,0 +1,85 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * and the Server Side Public License, v 1; you may not use this file except in
+ * compliance with, at your election, the Elastic License or the Server Side
+ * Public License, v 1.
+ */
+
+import { History } from 'history';
+import { filter } from 'rxjs/operators';
+import { DataPublicPluginStart } from '../../../../data/public';
+import {
+  createQueryParamObservable,
+  getQueryParams,
+  removeQueryParam,
+} from '../../../../kibana_utils/public';
+import { SEARCH_SESSION_ID_QUERY_PARAM } from '../../url_generator';
+
+export interface DiscoverSearchSessionManagerDeps {
+  history: History;
+  session: DataPublicPluginStart['search']['session'];
+}
+
+/**
+ * Helps with state management of search session and {@link SEARCH_SESSION_ID_QUERY_PARAM} in the URL
+ */
+export class DiscoverSearchSessionManager {
+  /**
+   * Notifies about `searchSessionId` changes in the URL,
+   * skips if `searchSessionId` matches current search session id
+   */
+  readonly newSearchSessionIdFromURL$ = createQueryParamObservable<string>(
+    this.deps.history,
+    SEARCH_SESSION_ID_QUERY_PARAM
+  ).pipe(
+    filter((searchSessionId) => {
+      if (!searchSessionId) return true;
+      return !this.deps.session.isCurrentSession(searchSessionId);
+    })
+  );
+
+  constructor(private readonly deps: DiscoverSearchSessionManagerDeps) {}
+
+  /**
+   * Get next session id by either starting or restoring a session.
+   * When navigating away from the restored session {@link SEARCH_SESSION_ID_QUERY_PARAM} is removed from the URL using history.replace
+   */
+  getNextSearchSessionId() {
+    let searchSessionIdFromURL = this.getSearchSessionIdFromURL();
+    if (searchSessionIdFromURL) {
+      if (
+        this.deps.session.isRestore() &&
+        this.deps.session.isCurrentSession(searchSessionIdFromURL)
+      ) {
+        // navigating away from a restored session
+        this.removeSearchSessionIdFromURL({ replace: true });
+        searchSessionIdFromURL = undefined;
+      } else {
+        this.deps.session.restore(searchSessionIdFromURL);
+      }
+    }
+
+    return searchSessionIdFromURL ?? this.deps.session.start();
+  }
+
+  /**
+   * Removes Discovers {@link SEARCH_SESSION_ID_QUERY_PARAM} from the URL
+   * @param replace - methods to change the URL
+   */
+  removeSearchSessionIdFromURL({ replace = true }: { replace?: boolean } = { replace: true }) {
+    if (this.hasSearchSessionIdInURL()) {
+      removeQueryParam(this.deps.history, SEARCH_SESSION_ID_QUERY_PARAM, replace);
+    }
+  }
+
+  /**
+   * If there is a {@link SEARCH_SESSION_ID_QUERY_PARAM} currently in the URL
+   */
+  hasSearchSessionIdInURL(): boolean {
+    return !!this.getSearchSessionIdFromURL();
+  }
+
+  private getSearchSessionIdFromURL = () =>
+    getQueryParams(this.deps.history.location)[SEARCH_SESSION_ID_QUERY_PARAM] as string | undefined;
+}

src/plugins/discover/public/application/angular/discover_state.ts

@@ -200,7 +200,7 @@ export function getState({
       setState(appStateContainerModified, defaultState);
     },
     getPreviousAppState: () => previousAppState,
-    flushToUrl: () => stateStorage.flush(),
+    flushToUrl: () => stateStorage.kbnUrlControls.flush(),
     isAppStateDirty: () => !isEqualState(initialAppState, appStateContainer.getState()),
   };
 }

src/plugins/kibana_utils/docs/state_sync/storages/kbn_url_storage.md

@@ -96,11 +96,11 @@ setTimeout(() => {
 }, 0);
 ```
 
-For cases, where granular control over URL updates is needed, `kbnUrlStateStorage` provides these advanced apis:
+For cases, where granular control over URL updates is needed, `kbnUrlStateStorage` exposes `kbnUrlStateStorage.kbnUrlControls` that exposes these advanced apis:
 
-- `kbnUrlStateStorage.flush({replace: boolean})` - allows to synchronously apply any pending updates.
-  `replace` option allows to use `history.replace()` instead of `history.push()`. Returned boolean indicates if any update happened
-- `kbnUrlStateStorage.cancel()` - cancels any pending updates
+- `kbnUrlStateStorage.kbnUrlControls.flush({replace: boolean})` - allows to synchronously apply any pending updates.
+  `replace` option allows using `history.replace()` instead of `history.push()`.
+- `kbnUrlStateStorage.kbnUrlControls.cancel()` - cancels any pending updates.
 
 ### Sharing one `kbnUrlStateStorage` instance
 

src/plugins/kibana_utils/public/history/history_observable.test.ts

@@ -0,0 +1,89 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * and the Server Side Public License, v 1; you may not use this file except in
+ * compliance with, at your election, the Elastic License or the Server Side
+ * Public License, v 1.
+ */
+
+import {
+  createHistoryObservable,
+  createQueryParamObservable,
+  createQueryParamsObservable,
+} from './history_observable';
+import { createMemoryHistory, History } from 'history';
+import { ParsedQuery } from 'query-string';
+
+let history: History;
+
+beforeEach(() => {
+  history = createMemoryHistory();
+});
+
+test('createHistoryObservable', () => {
+  const obs$ = createHistoryObservable(history);
+  const emits: string[] = [];
+  obs$.subscribe(({ location }) => {
+    emits.push(location.pathname + location.search);
+  });
+
+  history.push('/test');
+  history.push('/');
+
+  expect(emits.length).toEqual(2);
+  expect(emits).toMatchInlineSnapshot(`
+    Array [
+      "/test",
+      "/",
+    ]
+  `);
+});
+
+test('createQueryParamsObservable', () => {
+  const obs$ = createQueryParamsObservable(history);
+  const emits: ParsedQuery[] = [];
+  obs$.subscribe((params) => {
+    emits.push(params);
+  });
+
+  history.push('/test');
+  history.push('/test?foo=bar');
+  history.push('/?foo=bar');
+  history.push('/test?foo=bar&foo1=bar1');
+
+  expect(emits.length).toEqual(2);
+  expect(emits).toMatchInlineSnapshot(`
+    Array [
+      Object {
+        "foo": "bar",
+      },
+      Object {
+        "foo": "bar",
+        "foo1": "bar1",
+      },
+    ]
+  `);
+});
+
+test('createQueryParamObservable', () => {
+  const obs$ = createQueryParamObservable(history, 'foo');
+  const emits: unknown[] = [];
+  obs$.subscribe((param) => {
+    emits.push(param);
+  });
+
+  history.push('/test');
+  history.push('/test?foo=bar');
+  history.push('/?foo=bar');
+  history.push('/test?foo=baaaar&foo1=bar1');
+  history.push('/test?foo1=bar1');
+
+  expect(emits.length).toEqual(3);
+  expect(emits).toMatchInlineSnapshot(`
+    Array [
+      "bar",
+      "baaaar",
+      null,
+    ]
+  `);
+});

src/plugins/kibana_utils/public/history/history_observable.ts

@@ -0,0 +1,60 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * and the Server Side Public License, v 1; you may not use this file except in
+ * compliance with, at your election, the Elastic License or the Server Side
+ * Public License, v 1.
+ */
+
+import { Action, History, Location } from 'history';
+import { Observable } from 'rxjs';
+import { ParsedQuery } from 'query-string';
+import deepEqual from 'fast-deep-equal';
+import { map } from 'rxjs/operators';
+import { getQueryParams } from './get_query_params';
+import { distinctUntilChangedWithInitialValue } from '../../common';
+
+/**
+ * Convert history.listen into an observable
+ * @param history - {@link History} instance
+ */
+export function createHistoryObservable(
+  history: History
+): Observable<{ location: Location; action: Action }> {
+  return new Observable((observer) => {
+    const unlisten = history.listen((location, action) => observer.next({ location, action }));
+    return () => {
+      unlisten();
+    };
+  });
+}
+
+/**
+ * Create an observable that emits every time any of query params change.
+ * Uses deepEqual check.
+ * @param history - {@link History} instance
+ */
+export function createQueryParamsObservable(history: History): Observable<ParsedQuery> {
+  return createHistoryObservable(history).pipe(
+    map(({ location }) => ({ ...getQueryParams(location) })),
+    distinctUntilChangedWithInitialValue({ ...getQueryParams(history.location) }, deepEqual)
+  );
+}
+
+/**
+ * Create an observable that emits every time _paramKey_ changes
+ * @param history - {@link History} instance
+ * @param paramKey - query param key to observe
+ */
+export function createQueryParamObservable<Param = unknown>(
+  history: History,
+  paramKey: string
+): Observable<Param | null> {
+  return createQueryParamsObservable(history).pipe(
+    map((params) => (params[paramKey] ?? null) as Param | null),
+    distinctUntilChangedWithInitialValue(
+      (getQueryParams(history.location)[paramKey] ?? null) as Param | null,
+      deepEqual
+    )
+  );
+}

src/plugins/kibana_utils/public/history/index.ts

@@ -9,3 +9,4 @@
 export { removeQueryParam } from './remove_query_param';
 export { redirectWhenMissing } from './redirect_when_missing';
 export { getQueryParams } from './get_query_params';
+export * from './history_observable';

src/plugins/kibana_utils/public/index.ts

@@ -68,7 +68,14 @@ export {
   StopSyncStateFnType,
 } from './state_sync';
 export { Configurable, CollectConfigProps } from './ui';
-export { removeQueryParam, redirectWhenMissing, getQueryParams } from './history';
+export {
+  removeQueryParam,
+  redirectWhenMissing,
+  getQueryParams,
+  createQueryParamsObservable,
+  createHistoryObservable,
+  createQueryParamObservable,
+} from './history';
 export { applyDiff } from './state_management/utils/diff_object';
 export { createStartServicesGetter, StartServicesGetter } from './core/create_start_service_getter';
 

src/plugins/kibana_utils/public/state_sync/public.api.md

@@ -22,14 +22,12 @@ export const createSessionStorageStateStorage: (storage?: Storage) => ISessionSt
 
 // @public
 export interface IKbnUrlStateStorage extends IStateStorage {
-    cancel: () => void;
     // (undocumented)
     change$: <State = unknown>(key: string) => Observable<State | null>;
-    flush: (opts?: {
-        replace?: boolean;
-    }) => boolean;
     // (undocumented)
     get: <State = unknown>(key: string) => State | null;
+    // Warning: (ae-forgotten-export) The symbol "IKbnUrlControls" needs to be exported by the entry point index.d.ts
+    kbnUrlControls: IKbnUrlControls;
     // (undocumented)
     set: <State>(key: string, state: State, opts?: {
         replace: boolean;

src/plugins/kibana_utils/public/state_sync/state_sync.test.ts

@@ -255,7 +255,7 @@ describe('state_sync', () => {
       expect(history.length).toBe(startHistoryLength);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/"`);
 
-      urlSyncStrategy.flush();
+      urlSyncStrategy.kbnUrlControls.flush();
 
       expect(history.length).toBe(startHistoryLength + 1);
       expect(getCurrentUrl()).toMatchInlineSnapshot(
@@ -290,7 +290,7 @@ describe('state_sync', () => {
       expect(history.length).toBe(startHistoryLength);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/"`);
 
-      urlSyncStrategy.cancel();
+      urlSyncStrategy.kbnUrlControls.cancel();
 
       expect(history.length).toBe(startHistoryLength);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/"`);

src/plugins/kibana_utils/public/state_sync/state_sync_state_storage/create_kbn_url_state_storage.test.ts

@@ -39,11 +39,11 @@ describe('KbnUrlStateStorage', () => {
       const key = '_s';
       urlStateStorage.set(key, state);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/"`);
-      expect(urlStateStorage.flush()).toBe(true);
+      expect(!!urlStateStorage.kbnUrlControls.flush()).toBe(true);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/#?_s=(ok:1,test:test)"`);
       expect(urlStateStorage.get(key)).toEqual(state);
 
-      expect(urlStateStorage.flush()).toBe(false); // nothing to flush, not update
+      expect(!!urlStateStorage.kbnUrlControls.flush()).toBe(false); // nothing to flush, not update
     });
 
     it('should cancel url updates', async () => {
@@ -51,7 +51,7 @@ describe('KbnUrlStateStorage', () => {
       const key = '_s';
       const pr = urlStateStorage.set(key, state);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/"`);
-      urlStateStorage.cancel();
+      urlStateStorage.kbnUrlControls.cancel();
       await pr;
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/"`);
       expect(urlStateStorage.get(key)).toEqual(null);
@@ -215,11 +215,11 @@ describe('KbnUrlStateStorage', () => {
       const key = '_s';
       urlStateStorage.set(key, state);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/kibana/app/"`);
-      expect(urlStateStorage.flush()).toBe(true);
+      expect(!!urlStateStorage.kbnUrlControls.flush()).toBe(true);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/kibana/app/#?_s=(ok:1,test:test)"`);
       expect(urlStateStorage.get(key)).toEqual(state);
 
-      expect(urlStateStorage.flush()).toBe(false); // nothing to flush, not update
+      expect(!!urlStateStorage.kbnUrlControls.flush()).toBe(false); // nothing to flush, not update
     });
 
     it('should cancel url updates', async () => {
@@ -227,7 +227,7 @@ describe('KbnUrlStateStorage', () => {
       const key = '_s';
       const pr = urlStateStorage.set(key, state);
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/kibana/app/"`);
-      urlStateStorage.cancel();
+      urlStateStorage.kbnUrlControls.cancel();
       await pr;
       expect(getCurrentUrl()).toMatchInlineSnapshot(`"/kibana/app/"`);
       expect(urlStateStorage.get(key)).toEqual(null);

src/plugins/kibana_utils/public/state_sync/state_sync_state_storage/create_kbn_url_state_storage.ts

@@ -13,6 +13,7 @@ import { IStateStorage } from './types';
 import {
   createKbnUrlControls,
   getStateFromKbnUrl,
+  IKbnUrlControls,
   setStateToKbnUrl,
 } from '../../state_management/url';
 
@@ -39,16 +40,9 @@ export interface IKbnUrlStateStorage extends IStateStorage {
   change$: <State = unknown>(key: string) => Observable<State | null>;
 
   /**
-   * cancels any pending url updates
+   * Lower level wrapper around history library that handles batching multiple URL updates into one history change
    */
-  cancel: () => void;
-
-  /**
-   * Synchronously runs any pending url updates, returned boolean indicates if change occurred.
-   * @param opts: {replace? boolean} - allows to specify if push or replace should be used for flushing update
-   * @returns boolean - indicates if there was an update to flush
-   */
-  flush: (opts?: { replace?: boolean }) => boolean;
+  kbnUrlControls: IKbnUrlControls;
 }
 
 /**
@@ -114,11 +108,6 @@ export const createKbnUrlStateStorage = (
         }),
         share()
       ),
-    flush: ({ replace = false }: { replace?: boolean } = {}) => {
-      return !!url.flush(replace);
-    },
-    cancel() {
-      url.cancel();
-    },
+    kbnUrlControls: url,
   };
 };

test/functional/apps/discover/_discover.ts

@@ -227,7 +227,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       });
     });
     describe('usage of discover:searchOnPageLoad', () => {
-      it('should fetch data from ES initially when discover:searchOnPageLoad is false', async function () {
+      it('should not fetch data from ES initially when discover:searchOnPageLoad is false', async function () {
         await kibanaServer.uiSettings.replace({ 'discover:searchOnPageLoad': false });
         await PageObjects.common.navigateToApp('discover');
         await PageObjects.header.awaitKibanaChrome();
@@ -235,7 +235,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
         expect(await PageObjects.discover.getNrOfFetches()).to.be(0);
       });
 
-      it('should not fetch data from ES initially when discover:searchOnPageLoad is true', async function () {
+      it('should fetch data from ES initially when discover:searchOnPageLoad is true', async function () {
         await kibanaServer.uiSettings.replace({ 'discover:searchOnPageLoad': true });
         await PageObjects.common.navigateToApp('discover');
         await PageObjects.header.awaitKibanaChrome();

test/plugin_functional/test_suites/data_plugin/session.ts

@@ -42,10 +42,7 @@ export default function ({ getService, getPageObjects }: PluginFunctionalProvide
         await PageObjects.header.waitUntilLoadingHasFinished();
         const sessionIds = await getSessionIds();
 
-        // Discover calls destroy on index pattern change, which explicitly closes a session
-        expect(sessionIds.length).to.be(2);
-        expect(sessionIds[0].length).to.be(0);
-        expect(sessionIds[1].length).not.to.be(0);
+        expect(sessionIds.length).to.be(1);
       });
 
       it('Starts on a refresh', async () => {

x-pack/plugins/maps/public/routes/map_page/url_state/global_sync.ts

@@ -30,6 +30,6 @@ export function updateGlobalState(newState: MapsGlobalState, flushUrlState = fal
     ...newState,
   });
   if (flushUrlState) {
-    kbnUrlStateStorage.flush({ replace: true });
+    kbnUrlStateStorage.kbnUrlControls.flush(true);
   }
 }

x-pack/test/send_search_to_background_integration/tests/apps/dashboard/async_search/send_to_background.ts

@@ -30,9 +30,9 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       await searchSessions.deleteAllSearchSessions();
     });
 
-    it('Restore using non-existing sessionId errors out. Refresh starts a new session and completes.', async () => {
+    it('Restore using non-existing sessionId errors out. Refresh starts a new session and completes. Back button restores a session.', async () => {
       await PageObjects.dashboard.loadSavedDashboard('Not Delayed');
-      const url = await browser.getCurrentUrl();
+      let url = await browser.getCurrentUrl();
       const fakeSessionId = '__fake__';
       const savedSessionURL = `${url}&searchSessionId=${fakeSessionId}`;
       await browser.get(savedSessionURL);
@@ -53,6 +53,20 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
         'Sum of Bytes by Extension'
       );
       expect(session2).not.to.be(fakeSessionId);
+
+      // back button should restore the session:
+      url = await browser.getCurrentUrl();
+      expect(url).not.to.contain('searchSessionId');
+
+      await browser.goBack();
+
+      url = await browser.getCurrentUrl();
+      expect(url).to.contain('searchSessionId');
+      await PageObjects.header.waitUntilLoadingHasFinished();
+      await searchSessions.expectState('restored');
+      expect(
+        await dashboardPanelActions.getSearchSessionIdByTitle('Sum of Bytes by Extension')
+      ).to.be(fakeSessionId);
     });
 
     it('Saves and restores a session', async () => {

x-pack/test/send_search_to_background_integration/tests/apps/discover/async_search.ts

@@ -13,6 +13,7 @@ export default function ({ getPageObjects, getService }: FtrProviderContext) {
   const browser = getService('browser');
   const inspector = getService('inspector');
   const PageObjects = getPageObjects(['discover', 'common', 'timePicker', 'header']);
+  const searchSessions = getService('searchSessions');
 
   describe('discover async search', () => {
     before(async () => {
@@ -31,18 +32,33 @@ export default function ({ getPageObjects, getService }: FtrProviderContext) {
       expect(searchSessionId2).not.to.be(searchSessionId1);
     });
 
-    it('search session id should be picked up from the URL, non existing session id errors out', async () => {
-      const url = await browser.getCurrentUrl();
+    it('search session id should be picked up from the URL, non existing session id errors out, back button restores a session', async () => {
+      let url = await browser.getCurrentUrl();
       const fakeSearchSessionId = '__test__';
       const savedSessionURL = url + `&searchSessionId=${fakeSearchSessionId}`;
       await browser.navigateTo(savedSessionURL);
       await PageObjects.header.waitUntilLoadingHasFinished();
+      await searchSessions.expectState('restored');
       await testSubjects.existOrFail('discoverNoResultsError'); // expect error because of fake searchSessionId
       const searchSessionId1 = await getSearchSessionId();
       expect(searchSessionId1).to.be(fakeSearchSessionId);
       await queryBar.clickQuerySubmitButton();
+      await PageObjects.header.waitUntilLoadingHasFinished();
+      await searchSessions.expectState('completed');
       const searchSessionId2 = await getSearchSessionId();
       expect(searchSessionId2).not.to.be(searchSessionId1);
+
+      // back button should restore the session:
+      url = await browser.getCurrentUrl();
+      expect(url).not.to.contain('searchSessionId');
+
+      await browser.goBack();
+
+      url = await browser.getCurrentUrl();
+      expect(url).to.contain('searchSessionId');
+      await PageObjects.header.waitUntilLoadingHasFinished();
+      await searchSessions.expectState('restored');
+      expect(await getSearchSessionId()).to.be(fakeSearchSessionId);
     });
   });