feat(store): throw an error if not constructed with a helper

src/__tests__/store.js

@@ -71,6 +71,12 @@ describe('Store', () => {
     expect(store.algoliaHelper).toBe(helper);
   });
 
+  test('should throw an exception if not constructed with a helper', () => {
+    expect(() => {
+      new Store({});
+    }).toThrow(TypeError);
+  });
+
   test('should always use custom highlighting tags', () => {
     const client = algoliaClient('app_id', 'api_key');
     const helper = algoliaHelper(client);

src/store.js

@@ -47,13 +47,16 @@ const onHelperChange = function() {
 };
 
 export class Store {
-  constructor(algoliaHelper) {
+  constructor(helper) {
+    if (!(helper instanceof algoliaHelper.AlgoliaSearchHelper)) {
+      throw new TypeError('Expected an AlgoliaSearchHelper instance.');
+    }
     // We require one start() call to execute the first search query.
     // Allows every widget to alter the state at initialization
     // without trigger multiple queries.
     this._stoppedCounter = 1;
 
-    this.algoliaHelper = algoliaHelper;
+    this.algoliaHelper = helper;
   }
 
   set algoliaHelper(algoliaHelper) {