fix(error): directly emit error from events (#6472)

* fix(error): directly emit error from events

In `@algolia/events`, errors are properly rethrown if they are thrown with `.emit('error', new Error("msg"))`, not if they are thrown with `.emit('error', { error: new Error('msg') })`. Therefore in InstantSearch and the helper, all errors are now properly thrown directly in the emit.

[FX-3187]

BREAKING CHANGE: if you have any `on('error'` handler that reads `event.error` from the callback, change that to just `error`

* !fixup

packages/algoliasearch-helper/index.d.ts

@@ -74,7 +74,7 @@ declare namespace algoliasearchHelper {
       event: 'result',
       cb: (res: { results: SearchResults; state: SearchParameters }) => void
     ): this;
-    on(event: 'error', cb: (res: { error: Error }) => void): this;
+    on(event: 'error', cb: (res: Error) => void): this;
     on(event: 'searchQueueEmpty', cb: () => void): this;
 
     /**
@@ -338,7 +338,7 @@ declare namespace algoliasearchHelper {
         };
       }) => void
     ): this;
-    on(event: 'error', cb: (res: { error: Error }) => void): this;
+    on(event: 'error', cb: (res: Error) => void): this;
 
     lastResults: SearchResults | null;
     lastRecommendResults: RecommendResults | null;

packages/algoliasearch-helper/src/algoliasearch.helper.js

@@ -1329,9 +1329,7 @@ AlgoliaSearchHelper.prototype._search = function (options) {
       .catch(this._dispatchAlgoliaError.bind(this, queryId));
   } catch (error) {
     // If we reach this part, we're in an internal error state
-    this.emit('error', {
-      error: error,
-    });
+    this.emit('error', error);
   }
 
   return undefined;
@@ -1420,9 +1418,7 @@ AlgoliaSearchHelper.prototype._recommend = function () {
       .catch(this._dispatchRecommendError.bind(this, queryId));
   } catch (error) {
     // If we reach this part, we're in an internal error state
-    this.emit('error', {
-      error: error,
-    });
+    this.emit('error', error);
   }
 
   return;
@@ -1579,9 +1575,7 @@ AlgoliaSearchHelper.prototype._dispatchAlgoliaError = function (
   this._currentNbQueries -= queryId - this._lastQueryIdReceived;
   this._lastQueryIdReceived = queryId;
 
-  this.emit('error', {
-    error: error,
-  });
+  this.emit('error', error);
 
   if (this._currentNbQueries === 0) this.emit('searchQueueEmpty');
 };
@@ -1599,9 +1593,7 @@ AlgoliaSearchHelper.prototype._dispatchRecommendError = function (
     queryId - this._lastRecommendQueryIdReceived;
   this._lastRecommendQueryIdReceived = queryId;
 
-  this.emit('error', {
-    error: error,
-  });
+  this.emit('error', error);
 
   if (this._currentNbRecommendQueries === 0) this.emit('recommendQueueEmpty');
 };

packages/algoliasearch-helper/test/integration-spec/helper.distinct.facet.js

@@ -31,8 +31,8 @@ test('[INT][FILTERS] Using distinct should let me retrieve all facet without dis
     facets: ['colors'],
   });
 
-  helper.on('error', function (event) {
-    done.fail(event.error);
+  helper.on('error', function (error) {
+    done.fail(error);
   });
 
   helper.on('result', function (event) {

packages/algoliasearch-helper/test/integration-spec/helper.filters.js

@@ -32,8 +32,8 @@ test('[INT][FILTERS] Should retrieve different values for multi facetted records
 
   var calls = 0;
 
-  helper.on('error', function (event) {
-    done.fail(event.error);
+  helper.on('error', function (error) {
+    done.fail(error);
   });
 
   helper.on('result', function (event) {

packages/algoliasearch-helper/test/integration-spec/helper.numerics.js

@@ -32,8 +32,8 @@ test('[INT][NUMERICS][RAW-API]Test numeric operations on the helper and their re
 
   var calls = 0;
 
-  helper.on('error', function (event) {
-    done.fail(event.error);
+  helper.on('error', function (error) {
+    done.fail(error);
   });
 
   helper.on('result', function (event) {
@@ -84,8 +84,8 @@ test('[INT][NUMERICS][MANAGED-API]Test numeric operations on the helper and thei
 
   var calls = 0;
 
-  helper.on('error', function (event) {
-    done.fail(event.error);
+  helper.on('error', function (error) {
+    done.fail(error);
   });
 
   helper.on('result', function (event) {

packages/algoliasearch-helper/test/integration-spec/helper.searchOnce.js

@@ -30,8 +30,8 @@ test('[INT][SEARCHONCE] Should be able to search once with custom parameters wit
   var state0 = helper.state;
 
   var calls = 1;
-  helper.on('error', function (event) {
-    done.fail(event.error);
+  helper.on('error', function (error) {
+    done.fail(error);
   });
 
   helper.on('result', function (event) {

packages/algoliasearch-helper/test/integration-spec/helper.tags.js

@@ -32,8 +32,8 @@ test('[INT][TAGS]Test tags operations on the helper and their results on the alg
 
   var calls = 0;
 
-  helper.on('error', function (event) {
-    done.fail(event.error);
+  helper.on('error', function (error) {
+    done.fail(error);
   });
 
   helper.on('result', function (event) {

packages/algoliasearch-helper/test/spec/algoliasearch.helper/events.js

@@ -356,9 +356,7 @@ test('error event should be emitted once the request is complete with errors', f
 
   return runAllMicroTasks().then(function () {
     expect(errored).toHaveBeenCalledTimes(1);
-    expect(errored).toHaveBeenLastCalledWith({
-      error: expect.any(Error),
-    });
+    expect(errored).toHaveBeenLastCalledWith(expect.any(Error));
   });
 });
 
@@ -381,7 +379,5 @@ test('error event should be emitted if an error happens at request time', functi
   helper.search();
 
   expect(errored).toHaveBeenCalledTimes(1);
-  expect(errored).toHaveBeenLastCalledWith({
-    error: expect.any(Error),
-  });
+  expect(errored).toHaveBeenLastCalledWith(expect.any(Error));
 });

packages/instantsearch-core/src/__tests__/instantsearch-integration.test.ts

@@ -132,14 +132,11 @@ describe('errors', () => {
 
     search.addWidgets([connectSearchBox(() => {})({})]);
 
-    expect.assertions(4);
+    expect.assertions(2);
 
     search.on('error', (error) => {
       expect(error).toBeInstanceOf(Error);
       expect(error.message).toBe('test!');
-
-      expect(error.error).toBeInstanceOf(Error);
-      expect(error.error.message).toBe('test!');
     });
 
     search.start();

packages/instantsearch-core/src/__tests__/instantsearch.test.tsx

@@ -1108,9 +1108,9 @@ describe('start', () => {
     search.addWidgets([virtualSearchBox({})]);
     search.start();
 
-    search.on('error', (event) => {
+    search.on('error', (error) => {
       expect(searchClient.search).toHaveBeenCalledTimes(1);
-      expect(event.error).toEqual(new Error('SERVER_ERROR'));
+      expect(error).toEqual(new Error('SERVER_ERROR'));
       done();
     });
   });

packages/instantsearch-core/src/instantsearch.ts

@@ -402,28 +402,22 @@ See documentation: ${createDocumentationLink({
 
     // Only the "main" Helper emits the `error` event vs the one for `search`
     // and `results` that are also emitted on the derived one.
-    mainHelper.on('error', ({ error }) => {
+    mainHelper.on('error', (error) => {
       if (!(error instanceof Error)) {
         // typescript lies here, error is in some cases { name: string, message: string }
         const err = error as Record<string, any>;
-        error = Object.keys(err).reduce((acc, key) => {
+        this.error = Object.keys(err).reduce((acc, key) => {
           (acc as any)[key] = err[key];
           return acc;
         }, new Error(err.message));
+      } else {
+        this.error = error;
       }
-      // If an error is emitted, it is re-thrown by events. In previous versions
-      // we emitted {error}, which is thrown as:
-      // "Uncaught, unspecified \"error\" event. ([object Object])"
-      // To avoid breaking changes, we make the error available in both
-      // `error` and `error.error`
-      // @MAJOR emit only error
-      (error as any).error = error;
-      this.error = error;
       this.status = 'error';
       this.scheduleRender(false);
 
       // This needs to execute last because it throws the error.
-      this.emit('error', error);
+      this.emit('error', this.error);
     });
 
     this.mainHelper = mainHelper;