fix(index): support custom UI params in inconsistent UI state warning

src/lib/__tests__/InstantSearch-test.js

@@ -1226,6 +1226,13 @@ describe('UI state', () => {
           menu: {
             category: 'Hardware',
           },
+          // `places` is a UI parameter that is not supported by default but that
+          // can be added when using custom widgets. Having it in `initialUiState`
+          // makes sure that it doesn't throw if it happens.
+          places: {
+            query: 'Paris',
+            location: ['1', '1'],
+          },
         },
       },
     });

src/widgets/index/index.ts

@@ -394,6 +394,10 @@ const index = (props: IndexProps): Index => {
             const requiredWidgets: Array<Widget['$$type']> =
               stateToWidgetsMap[parameter];
 
+            if (!requiredWidgets) {
+              return acc;
+            }
+
             if (
               !requiredWidgets.some(requiredWidget =>
                 mountedWidgets.includes(requiredWidget)