feat(recommend): introduce connectRelatedProducts connector

bundlesize.config.json

@@ -10,19 +10,19 @@
     },
     {
       "path": "./packages/instantsearch.js/dist/instantsearch.production.min.js",
-      "maxSize": "77.75 kB"
+      "maxSize": "78 kB"
     },
     {
       "path": "./packages/instantsearch.js/dist/instantsearch.development.js",
-      "maxSize": "171 kB"
+      "maxSize": "171.5 kB"
     },
     {
       "path": "packages/react-instantsearch-core/dist/umd/ReactInstantSearchCore.min.js",
-      "maxSize": "47.5 kB"
+      "maxSize": "47.75 kB"
     },
     {
       "path": "packages/react-instantsearch/dist/umd/ReactInstantSearch.min.js",
-      "maxSize": "59.25 kB"
+      "maxSize": "59.5 kB"
     },
     {
       "path": "packages/vue-instantsearch/vue2/umd/index.js",

packages/instantsearch.js/src/__tests__/common-connectors.test.tsx

@@ -15,6 +15,7 @@ import {
   connectRatingMenu,
   connectRefinementList,
   connectToggleRefinement,
+  connectRelatedProducts,
 } from '../connectors';
 import instantsearch from '../index.es';
 import { refinementList } from '../widgets';
@@ -392,6 +393,31 @@ const testSetups: TestSetupsMap<TestSuites> = {
       })
       .start();
   },
+  createRelatedProductsConnectorTests({ instantSearchOptions, widgetParams }) {
+    const customRelatedProducts = connectRelatedProducts<{
+      container: HTMLElement;
+    }>((renderOptions) => {
+      renderOptions.widgetParams.container.innerHTML = `
+        <ul>${renderOptions.recommendations
+          .map((recommendation) => `<li>${recommendation.objectID}</li>`)
+          .join('')}</ul>`;
+    });
+
+    instantsearch(instantSearchOptions)
+      .addWidgets([
+        customRelatedProducts({
+          container: document.body.appendChild(document.createElement('div')),
+          ...widgetParams,
+        }),
+      ])
+      .on('error', () => {
+        /*
+         * prevent rethrowing InstantSearch errors, so tests can be asserted.
+         * IRL this isn't needed, as the error doesn't stop execution.
+         */
+      })
+      .start();
+  },
 };
 
 const testOptions: TestOptionsMap<TestSuites> = {
@@ -405,6 +431,7 @@ const testOptions: TestOptionsMap<TestSuites> = {
   createNumericMenuConnectorTests: undefined,
   createRatingMenuConnectorTests: undefined,
   createToggleRefinementConnectorTests: undefined,
+  createRelatedProductsConnectorTests: undefined,
 };
 
 describe('Common connector tests (InstantSearch.js)', () => {

packages/instantsearch.js/src/connectors/index.ts

@@ -30,6 +30,7 @@ export { default as connectNumericMenu } from './numeric-menu/connectNumericMenu
 export { default as connectPagination } from './pagination/connectPagination';
 export { default as connectRange } from './range/connectRange';
 export { default as connectRefinementList } from './refinement-list/connectRefinementList';
+export { default as connectRelatedProducts } from './related-products/connectRelatedProducts';
 export { default as connectSearchBox } from './search-box/connectSearchBox';
 export { default as connectSortBy } from './sort-by/connectSortBy';
 export { default as connectRatingMenu } from './rating-menu/connectRatingMenu';

packages/instantsearch.js/src/connectors/related-products/connectRelatedProducts.ts

@@ -0,0 +1,156 @@
+import {
+  createDocumentationMessageGenerator,
+  checkRendering,
+  noop,
+} from '../../lib/utils';
+
+import type { Connector, TransformItems, Hit, BaseHit } from '../../types';
+import type {
+  PlainSearchParameters,
+  RecommendResultItem,
+} from 'algoliasearch-helper';
+
+const withUsage = createDocumentationMessageGenerator({
+  name: 'related-products',
+  connector: true,
+});
+
+export type RelatedProductsRenderState<THit extends BaseHit = BaseHit> = {
+  /**
+   * The matched recommendations from the Algolia API.
+   */
+  recommendations: Array<Hit<THit>>;
+};
+
+export type RelatedProductsConnectorParams<THit extends BaseHit = BaseHit> = {
+  /**
+   * The `objectIDs` of the items to get related products from.
+   */
+  objectIDs: string[];
+  /**
+   * The number of recommendations to retrieve.
+   */
+  maxRecommendations?: number;
+  /**
+   * The threshold for the recommendations confidence score (between 0 and 100).
+   */
+  threshold?: number;
+  /**
+   * List of search parameters to send.
+   */
+  fallbackParameters?: Omit<
+    PlainSearchParameters,
+    'page' | 'hitsPerPage' | 'offset' | 'length'
+  >;
+  /**
+   * List of search parameters to send.
+   */
+  queryParameters?: Omit<
+    PlainSearchParameters,
+    'page' | 'hitsPerPage' | 'offset' | 'length'
+  >;
+  /**
+   * Function to transform the items passed to the templates.
+   */
+  transformItems?: TransformItems<Hit<THit>, { results: RecommendResultItem }>;
+};
+
+export type RelatedProductsWidgetDescription<THit extends BaseHit = BaseHit> = {
+  $$type: 'ais.relatedProducts';
+  renderState: RelatedProductsRenderState<THit>;
+};
+
+export type RelatedProductsConnector<THit extends BaseHit = BaseHit> =
+  Connector<
+    RelatedProductsWidgetDescription<THit>,
+    RelatedProductsConnectorParams<THit>
+  >;
+
+const connectRelatedProducts: RelatedProductsConnector =
+  function connectRelatedProducts(renderFn, unmountFn = noop) {
+    checkRendering(renderFn, withUsage());
+
+    return function relatedProducts(widgetParams) {
+      const {
+        objectIDs,
+        maxRecommendations,
+        threshold,
+        fallbackParameters,
+        queryParameters,
+        transformItems = ((items) => items) as NonNullable<
+          RelatedProductsConnectorParams['transformItems']
+        >,
+      } = widgetParams || {};
+
+      if (!objectIDs || objectIDs.length === 0) {
+        throw new Error(withUsage('The `objectIDs` option is required.'));
+      }
+
+      return {
+        dependsOn: 'recommend',
+        $$type: 'ais.relatedProducts',
+
+        init(initOptions) {
+          renderFn(
+            {
+              ...this.getWidgetRenderState(initOptions),
+              instantSearchInstance: initOptions.instantSearchInstance,
+            },
+            true
+          );
+        },
+
+        render(renderOptions) {
+          const renderState = this.getWidgetRenderState(renderOptions);
+
+          renderFn(
+            {
+              ...renderState,
+              instantSearchInstance: renderOptions.instantSearchInstance,
+            },
+            false
+          );
+        },
+
+        getRenderState(renderState) {
+          return renderState;
+        },
+
+        getWidgetRenderState({ results }) {
+          if (results === null || results === undefined) {
+            return { recommendations: [], widgetParams };
+          }
+
+          return {
+            recommendations: transformItems(results.hits, {
+              results: results as RecommendResultItem,
+            }),
+            widgetParams,
+          };
+        },
+
+        dispose({ state }) {
+          unmountFn();
+
+          return state;
+        },
+
+        getWidgetParameters(state) {
+          // We only use the first `objectID` to get the recommendations for
+          // until we implement support for multiple `objectIDs` in the helper.
+          const objectID = objectIDs[0];
+
+          return state.addRelatedProducts({
+            objectID,
+            maxRecommendations,
+            threshold,
+            fallbackParameters,
+            queryParameters,
+            $$id: this.$$id!,
+          });
+        },
+      };
+    };
+  };
+
+export default connectRelatedProducts;

packages/instantsearch.js/src/lib/utils/addWidgetId.ts

@@ -0,0 +1,11 @@
+import type { Widget } from '../../types';
+
+let id = 0;
+
+export function addWidgetId(widget: Widget) {
+  if (widget.dependsOn !== 'recommend') {
+    return;
+  }
+
+  widget.$$id = id++;
+}

packages/instantsearch.js/src/types/widget.ts

@@ -158,7 +158,7 @@ type RecommendWidget<
   TWidgetDescription extends WidgetDescription & WidgetParams
 > = {
   dependsOn: 'recommend';
-  $$id: number;
+  $$id?: number;
   getWidgetParameters: (
     state: RecommendParameters,
     widgetParametersOptions: {

packages/instantsearch.js/src/widgets/index/__tests__/index-test.ts

@@ -109,17 +109,19 @@ describe('index', () => {
       ...args,
     });
 
-  const createFrequentlyBoughtTogether = (args: Partial<Widget> = {}): Widget =>
+  const createFrequentlyBoughtTogether = (
+    args: Partial<Widget> = {}
+  ): Widget & { $$id: number } =>
     createWidget({
       dependsOn: 'recommend',
-      getWidgetParameters: jest.fn((parameters) => {
+      getWidgetParameters(parameters) {
         return parameters.addFrequentlyBoughtTogether({
-          $$id: 1,
+          $$id: this.$$id!,
           objectID: 'abc',
         });
-      }),
+      },
       ...args,
-    } as unknown as Widget);
+    } as Widget) as unknown as Widget & { $$id: number };
 
   const virtualSearchBox = connectSearchBox(() => {});
   const virtualPagination = connectPagination(() => {});
@@ -226,6 +228,17 @@ See documentation: https://www.algolia.com/doc/api-reference/widgets/index-widge
 `);
     });
 
+    it('adds generated `$$id` to widgets that depend on `recommend`', () => {
+      const instance = index({ indexName: 'indexName' });
+      const fbt1 = createFrequentlyBoughtTogether({});
+      const fbt2 = createFrequentlyBoughtTogether({});
+
+      instance.addWidgets([fbt1, fbt2]);
+
+      expect(fbt1.$$id).toBe(0);
+      expect(fbt2.$$id).toBe(1);
+    });
+
     describe('with a started instance', () => {
       it('updates the internal state with added widgets', () => {
         const instance = index({ indexName: 'indexName' });
@@ -270,9 +283,10 @@ See documentation: https://www.algolia.com/doc/api-reference/widgets/index-widge
         instance.init(createIndexInitOptions({ parent: null }));
 
         const fbt = createFrequentlyBoughtTogether({});
+        const getWidgetParameters = jest.spyOn(fbt, 'getWidgetParameters');
         instance.addWidgets([fbt]);
 
-        expect(fbt.getWidgetParameters).toHaveBeenCalledTimes(1);
+        expect(getWidgetParameters).toHaveBeenCalledTimes(1);
       });
 
       it('calls getWidgetParameters after init on widgets that depend on search and implement the function', () => {
@@ -1216,11 +1230,12 @@ See documentation: https://www.algolia.com/doc/api-reference/widgets/index-widge
       const instance = index({ indexName: 'indexName' });
 
       const fbt = createFrequentlyBoughtTogether({});
+      const getWidgetParameters = jest.spyOn(fbt, 'getWidgetParameters');
       instance.addWidgets([fbt]);
 
       instance.init(createIndexInitOptions({ parent: null }));
 
-      expect(fbt.getWidgetParameters).toHaveBeenCalledTimes(1);
+      expect(getWidgetParameters).toHaveBeenCalledTimes(1);
     });
 
     it('calls getWidgetParameters on widgets that depend on search and implement the function', () => {
@@ -2978,9 +2993,9 @@ See documentation: https://www.algolia.com/doc/api-reference/widgets/index-widge
       });
 
       const fbt = createFrequentlyBoughtTogether({
-        $$id: 1,
         dependsOn: 'recommend',
         shouldRender: () => true,
+        render: jest.fn(),
       });
       instance.addWidgets([fbt]);
 

packages/instantsearch.js/src/widgets/index/index.ts

@@ -10,6 +10,7 @@ import {
   createInitArgs,
   createRenderArgs,
 } from '../../lib/utils';
+import { addWidgetId } from '../../lib/utils/addWidgetId';
 
 import type {
   InstantSearch,
@@ -306,7 +307,7 @@ const index = (widgetParams: IndexWidgetParams): IndexWidget => {
       if (
         widget.dependsOn !== 'recommend' ||
         isIndexWidget(widget) ||
-        !widget.$$id
+        widget.$$id === undefined
       ) {
         return this.getResults();
       }
@@ -376,6 +377,14 @@ const index = (widgetParams: IndexWidgetParams): IndexWidget => {
         );
       }
 
+      widgets.forEach((widget) => {
+        if (isIndexWidget(widget)) {
+          return;
+        }
+
+        addWidgetId(widget);
+      });
+
       localWidgets = localWidgets.concat(widgets);
 
       if (localInstantSearchInstance && Boolean(widgets.length)) {

packages/react-instantsearch/src/__tests__/common-connectors.test.tsx

@@ -313,6 +313,7 @@ const testSetups: TestSetupsMap<TestSuites> = {
       </InstantSearch>
     );
   },
+  createRelatedProductsConnectorTests: () => {},
 };
 
 const testOptions: TestOptionsMap<TestSuites> = {
@@ -332,6 +333,12 @@ const testOptions: TestOptionsMap<TestSuites> = {
   createNumericMenuConnectorTests: { act },
   createRatingMenuConnectorTests: { act },
   createToggleRefinementConnectorTests: { act },
+  createRelatedProductsConnectorTests: {
+    act,
+    skippedTests: {
+      options: true,
+    },
+  },
 };
 
 describe('Common connector tests (React InstantSearch)', () => {