fix(insightsMiddleware): throw an error when credentials can't be ext…

…racted (#4901)

* fix(insightsMiddleware): throw an error when credentials can't be extracted

When api or appId is missing, an error gets thrown by search insights, but that doesn't explain *why* that error gets thrown.

Ideally this would also clarify what the next step is (usually making sure to spread the previous search client, or leaving all properties in place, but i'm not too sure how to word that.

This doesn't add a new error where there wasn't already one, as the search-insights library threw an error in this case already.

* only dev mode, avoid bundle size bloat

* can't be bothered with the ts

src/middlewares/__tests__/createInsightsMiddleware.ts

@@ -8,19 +8,22 @@ import { createSearchClient } from '../../../test/mock/createSearchClient';
 import { warning } from '../../lib/utils';
 
 describe('insights', () => {
-  const createTestEnvironment = () => {
+  const searchClientWithCredentials = createSearchClient({
+    // @ts-expect-error only available in search client v4
+    transporter: {
+      headers: {
+        'x-algolia-application-id': 'myAppId',
+        'x-algolia-api-key': 'myApiKey',
+      },
+    },
+  });
+  const createTestEnvironment = ({
+    searchClient = searchClientWithCredentials,
+  } = {}) => {
     const { analytics, insightsClient } = createInsights();
     const indexName = 'my-index';
     const instantSearchInstance = instantsearch({
-      searchClient: createSearchClient({
-        // @ts-expect-error only available in search client v4
-        transporter: {
-          headers: {
-            'x-algolia-application-id': 'myAppId',
-            'x-algolia-api-key': 'myApiKey',
-          },
-        },
-      }),
+      searchClient,
       indexName,
     });
     instantSearchInstance.start();
@@ -114,6 +117,19 @@ describe('insights', () => {
       });
     });
 
+    it('throws when search client does not have credentials', () => {
+      const { insightsClient, instantSearchInstance } = createTestEnvironment({
+        searchClient: createSearchClient(),
+      });
+      expect(() =>
+        createInsightsMiddleware({
+          insightsClient,
+        })({ instantSearchInstance })
+      ).toThrowErrorMatchingInlineSnapshot(
+        `"[insights middleware]: could not extract Algolia credentials from searchClient"`
+      );
+    });
+
     it('does not throw without userToken in UMD with the library loaded after the event', () => {
       const {
         insightsClient,

src/middlewares/createInsightsMiddleware.ts

@@ -59,6 +59,14 @@ export const createInsightsMiddleware: CreateInsightsMiddleware = (props) => {
 
   return ({ instantSearchInstance }) => {
     const [appId, apiKey] = getAppIdAndApiKey(instantSearchInstance.client);
+
+    // search-insights.js also throws an error so dev-only clarification is sufficient
+    if (__DEV__ && !(appId && apiKey)) {
+      throw new Error(
+        '[insights middleware]: could not extract Algolia credentials from searchClient'
+      );
+    }
+
     let queuedUserToken: string | undefined = undefined;
     let userTokenBeforeInit: string | undefined = undefined;
 

src/widgets/hits/__tests__/hits-integration-test.ts

@@ -31,6 +31,8 @@ const createSearchClient = ({
         ),
       })
     ),
+    applicationID: 'latency',
+    apiKey: '123',
   };
 };
 

src/widgets/infinite-hits/__tests__/infinite-hits-integration-test.ts

@@ -33,6 +33,8 @@ describe('infiniteHits', () => {
             ),
           }) as any
       ),
+      // credentials are stored like this in client v3, but not part of the SearchClient type
+      ...({ applicationID: 'latency', apiKey: '123' } as any),
     });
     const search = instantsearch({
       indexName: 'instant_search',