fix(userToken): prevent search waterfall

packages/instantsearch.js/src/middlewares/__tests__/createInsightsMiddleware.ts

@@ -16,6 +16,8 @@ import type { JSDOM } from 'jsdom';
 import type { PlainSearchParameters } from 'algoliasearch-helper';
 import { fireEvent } from '@testing-library/dom';
 import { createInstantSearch } from '../../../test/createInstantSearch';
+import { castToJestMock } from '@instantsearch/testutils';
+import { connectSearchBox } from '../../connectors';
 
 declare const jsdom: JSDOM;
 
@@ -43,6 +45,7 @@ describe('insights', () => {
     started = true,
     insights = false,
   } = {}) => {
+    castToJestMock(searchClient.search).mockClear();
     const { analytics, insightsClient } = createInsights();
     const indexName = 'my-index';
     const instantSearchInstance = instantsearch({
@@ -107,6 +110,8 @@ describe('insights', () => {
     (window as any).aa = undefined;
 
     document.body.innerHTML = '';
+
+    document.cookie = '_ALGOLIA=;';
   });
 
   describe('usage', () => {
@@ -621,6 +626,76 @@ See documentation: https://www.algolia.com/doc/guides/building-search-ui/going-f
       ).toEqual('def');
     });
 
+    it('searches once per unique userToken', async () => {
+      const { insightsClient, instantSearchInstance } = createTestEnvironment();
+
+      instantSearchInstance.addWidgets([connectSearchBox(() => ({}))({})]);
+
+      await wait(0);
+      expect(instantSearchInstance.client.search).toHaveBeenCalledTimes(1);
+
+      insightsClient('setUserToken', 'abc');
+      instantSearchInstance.use(
+        createInsightsMiddleware({
+          insightsClient,
+        })
+      );
+
+      await wait(0);
+      expect(instantSearchInstance.client.search).toHaveBeenCalledTimes(2);
+
+      insightsClient('setUserToken', 'abc');
+
+      await wait(0);
+      expect(instantSearchInstance.client.search).toHaveBeenCalledTimes(2);
+    });
+
+    it("doesn't search when userToken is falsy", async () => {
+      const { insightsClient, instantSearchInstance } = createTestEnvironment();
+
+      instantSearchInstance.addWidgets([connectSearchBox(() => ({}))({})]);
+
+      await wait(0);
+      expect(instantSearchInstance.client.search).toHaveBeenCalledTimes(1);
+      expect(instantSearchInstance.client.search).toHaveBeenLastCalledWith([
+        {
+          indexName: 'my-index',
+          params: {
+            facets: [],
+            query: '',
+            tagFilters: '',
+          },
+        },
+      ]);
+
+      insightsClient('setUserToken', 0);
+      instantSearchInstance.use(
+        createInsightsMiddleware({
+          insightsClient,
+          insightsInitParams: { useCookie: false },
+        })
+      );
+
+      await wait(0);
+      expect(instantSearchInstance.client.search).toHaveBeenCalledTimes(2);
+      expect(instantSearchInstance.client.search).toHaveBeenLastCalledWith([
+        {
+          indexName: 'my-index',
+          params: {
+            clickAnalytics: true,
+            facets: [],
+            query: '',
+            tagFilters: '',
+          },
+        },
+      ]);
+
+      insightsClient('setUserToken', undefined);
+
+      await wait(0);
+      expect(instantSearchInstance.client.search).toHaveBeenCalledTimes(2);
+    });
+
     describe('umd', () => {
       it('applies userToken from queue if exists', () => {
         const {
@@ -816,8 +891,6 @@ See documentation: https://www.algolia.com/doc/guides/building-search-ui/going-f
     await wait(100);
     // url should not get cleared
     expect(document.location.href).toEqual(url);
-
-    document.cookie = '';
   });
 
   test('does not throw error when document or cookie are undefined', () => {

packages/instantsearch.js/src/middlewares/createInsightsMiddleware.ts

@@ -186,12 +186,21 @@ export function createInsightsMiddleware<
         }
 
         const setUserTokenToSearch = (userToken?: string) => {
+          if (!userToken) {
+            return;
+          }
+
+          const existingToken = (helper.state as PlainSearchParameters)
+            .userToken;
+
           helper.overrideStateWithoutTriggeringChangeEvent({
             ...helper.state,
             userToken,
           });
 
-          instantSearchInstance.scheduleSearch();
+          if (existingToken && existingToken !== userToken) {
+            instantSearchInstance.scheduleSearch();
+          }
         };
 
         const anonymousUserToken = getInsightsAnonymousUserTokenInternal();
@@ -204,8 +213,10 @@ export function createInsightsMiddleware<
         // We consider the `userToken` coming from a `init` call to have a higher
         // importance than the one coming from the queue.
         if (userTokenBeforeInit) {
+          setUserTokenToSearch(userTokenBeforeInit);
           insightsClient('setUserToken', userTokenBeforeInit);
         } else if (queuedUserToken) {
+          setUserTokenToSearch(queuedUserToken);
           insightsClient('setUserToken', queuedUserToken);
         }