[Search][Discover] Restore searchSessionId from URL (#81633) (#83162)

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

@@ -83,6 +83,8 @@ import {
   MODIFY_COLUMNS_ON_SWITCH,
 } from '../../../common';
 import { METRIC_TYPE } from '@kbn/analytics';
+import { SEARCH_SESSION_ID_QUERY_PARAM } from '../../url_generator';
+import { removeQueryParam, getQueryParams } from '../../../../kibana_utils/public';
 
 const fetchStatuses = {
   UNINITIALIZED: 'uninitialized',
@@ -91,6 +93,9 @@ const fetchStatuses = {
   ERROR: 'error',
 };
 
+const getSearchSessionIdFromURL = (history) =>
+  getQueryParams(history.location)[SEARCH_SESSION_ID_QUERY_PARAM];
+
 const app = getAngularModule();
 
 app.config(($routeProvider) => {
@@ -208,6 +213,8 @@ function discoverController($element, $route, $scope, $timeout, $window, Promise
   };
 
   const history = getHistory();
+  // used for restoring background session
+  let isInitialSearch = true;
 
   const {
     appStateContainer,
@@ -798,17 +805,30 @@ function discoverController($element, $route, $scope, $timeout, $window, Promise
     if (abortController) abortController.abort();
     abortController = new AbortController();
 
-    const sessionId = data.search.session.start();
+    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();
+    })();
 
     $scope
       .updateDataSource()
       .then(setupVisualization)
       .then(function () {
         $scope.fetchStatus = fetchStatuses.LOADING;
-        logInspectorRequest();
+        logInspectorRequest({ searchSessionId });
         return $scope.searchSource.fetch({
           abortSignal: abortController.signal,
-          sessionId,
+          sessionId: searchSessionId,
         });
       })
       .then(onResults)
@@ -900,15 +920,15 @@ function discoverController($element, $route, $scope, $timeout, $window, Promise
     $scope.fetchStatus = fetchStatuses.COMPLETE;
   }
 
-  function logInspectorRequest() {
+  function logInspectorRequest({ searchSessionId = null } = { searchSessionId: null }) {
     inspectorAdapters.requests.reset();
     const title = i18n.translate('discover.inspectorRequestDataTitle', {
       defaultMessage: 'data',
     });
     const description = i18n.translate('discover.inspectorRequestDescription', {
       defaultMessage: 'This request queries Elasticsearch to fetch the data for the search.',
     });
-    inspectorRequest = inspectorAdapters.requests.start(title, { description });
+    inspectorRequest = inspectorAdapters.requests.start(title, { description, searchSessionId });
     inspectorRequest.stats(getRequestInspectorStats($scope.searchSource));
     $scope.searchSource.getSearchRequestBody().then((body) => {
       inspectorRequest.json(body);

src/plugins/discover/public/url_generator.test.ts

@@ -212,6 +212,15 @@ describe('Discover url generator', () => {
     });
   });
 
+  test('can specify a search session id', async () => {
+    const { generator } = await setup();
+    const url = await generator.createUrl({
+      searchSessionId: '__test__',
+    });
+    expect(url).toMatchInlineSnapshot(`"xyz/app/discover#/?_g=()&_a=()&searchSessionId=__test__"`);
+    expect(url).toContain('__test__');
+  });
+
   describe('useHash property', () => {
     describe('when default useHash is set to false', () => {
       test('when using default, sets index pattern ID in the generated URL', async () => {

src/plugins/discover/public/url_generator.ts

@@ -67,13 +67,20 @@ export interface DiscoverUrlGeneratorState {
    * whether to hash the data in the url to avoid url length issues.
    */
   useHash?: boolean;
+
+  /**
+   * Background search session id
+   */
+  searchSessionId?: string;
 }
 
 interface Params {
   appBasePath: string;
   useHash: boolean;
 }
 
+export const SEARCH_SESSION_ID_QUERY_PARAM = 'searchSessionId';
+
 export class DiscoverUrlGenerator
   implements UrlGeneratorsDefinition<typeof DISCOVER_APP_URL_GENERATOR> {
   constructor(private readonly params: Params) {}
@@ -88,6 +95,7 @@ export class DiscoverUrlGenerator
     savedSearchId,
     timeRange,
     useHash = this.params.useHash,
+    searchSessionId,
   }: DiscoverUrlGeneratorState): Promise<string> => {
     const savedSearchPath = savedSearchId ? encodeURIComponent(savedSearchId) : '';
     const appState: {
@@ -111,6 +119,10 @@ export class DiscoverUrlGenerator
     url = setStateToKbnUrl<QueryState>('_g', queryState, { useHash }, url);
     url = setStateToKbnUrl('_a', appState, { useHash }, url);
 
+    if (searchSessionId) {
+      url = `${url}&${SEARCH_SESSION_ID_QUERY_PARAM}=${searchSessionId}`;
+    }
+
     return url;
   };
 }

x-pack/test/functional/apps/discover/async_search.ts

@@ -0,0 +1,58 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+import expect from '@kbn/expect';
+import { FtrProviderContext } from '../../ftr_provider_context';
+
+export default function ({ getPageObjects, getService }: FtrProviderContext) {
+  const esArchiver = getService('esArchiver');
+  const queryBar = getService('queryBar');
+  const testSubjects = getService('testSubjects');
+  const browser = getService('browser');
+  const inspector = getService('inspector');
+  const PageObjects = getPageObjects(['discover', 'common', 'timePicker', 'header']);
+
+  describe('discover async search', () => {
+    before(async () => {
+      await esArchiver.loadIfNeeded('logstash_functional');
+      await esArchiver.load('discover/default');
+      await PageObjects.common.navigateToApp('discover');
+      await PageObjects.timePicker.setDefaultAbsoluteRange();
+      await PageObjects.header.waitUntilLoadingHasFinished();
+    });
+
+    it('search session id should change between searches', async () => {
+      const searchSessionId1 = await getSearchSessionId();
+      expect(searchSessionId1).not.to.be.empty();
+      await queryBar.clickQuerySubmitButton();
+      const searchSessionId2 = await getSearchSessionId();
+      expect(searchSessionId2).not.to.be(searchSessionId1);
+    });
+
+    // NOTE: this test will be revised when
+    // `searchSessionId` functionality actually works
+    it('search session id should be picked up from the URL', async () => {
+      const url = await browser.getCurrentUrl();
+      const fakeSearchSessionId = '__test__';
+      const savedSessionURL = url + `&searchSessionId=${fakeSearchSessionId}`;
+      await browser.navigateTo(savedSessionURL);
+      await PageObjects.header.waitUntilLoadingHasFinished();
+      const searchSessionId1 = await getSearchSessionId();
+      expect(searchSessionId1).to.be(fakeSearchSessionId);
+      await queryBar.clickQuerySubmitButton();
+      const searchSessionId2 = await getSearchSessionId();
+      expect(searchSessionId2).not.to.be(searchSessionId1);
+    });
+  });
+
+  async function getSearchSessionId(): Promise<string> {
+    await inspector.open();
+    const searchSessionId = await (
+      await testSubjects.find('inspectorRequestSearchSessionId')
+    ).getAttribute('data-search-session-id');
+    await inspector.close();
+    return searchSessionId;
+  }
+}

x-pack/test/functional/apps/discover/index.ts

@@ -16,5 +16,6 @@ export default function ({ loadTestFile }: FtrProviderContext) {
     loadTestFile(require.resolve('./error_handling'));
     loadTestFile(require.resolve('./visualize_field'));
     loadTestFile(require.resolve('./value_suggestions'));
+    loadTestFile(require.resolve('./async_search'));
   });
 }