fix(infinite-hits): fix #2543 (#2948)

The infinite hits widget is based internally on the hits widget which
accepts the allItems template. However this template is not usable for
the purpose of the infinite hits widget.

In order to prevent users from using this buggy and yet accepted option
this PR generates a exception if we detect this particular template.

Fix #2543

src/widgets/infinite-hits/__tests__/infinite-hits-test.js

@@ -76,9 +76,17 @@ describe('infiniteHits()', () => {
     expect(ReactDOM.render.secondCall.args[1]).toEqual(container);
   });
 
-  it('does not accept both item and allItems templates', () => {
-    expect(
-      infiniteHits.bind({ container, templates: { item: '', allItems: '' } })
+  it('does not accept allItems templates', () => {
+    expect(() =>
+      infiniteHits({ container, templates: { allItems: '' } })
+    ).toThrow();
+
+    expect(() =>
+      infiniteHits({ container, templates: { allItems: 'not empty' } })
+    ).toThrow();
+
+    expect(() =>
+      infiniteHits({ container, templates: { allItems: () => 'template' } })
     ).toThrow();
   });
 

src/widgets/infinite-hits/infinite-hits.js

@@ -124,6 +124,14 @@ export default function infiniteHits({
     throw new Error(`Must provide a container.${usage}`);
   }
 
+  // We have this specific check because unlike the hits, infiniteHits does not support this template.
+  // This can be misleading as they are very similar.
+  if (templates.allItems !== undefined) {
+    throw new Error(
+      'allItems is not a valid template for the infiniteHits widget'
+    );
+  }
+
   const containerNode = getContainerNode(container);
   const cssClasses = {
     root: cx(bem(null), userCssClasses.root),