[IMP] store: display error if no store found

src/store.ts

@@ -84,6 +84,9 @@ const isStrictEqual = (a, b) => a === b;
 export function useStore(selector, options: SelectorOptions = {}): any {
   const component: Component<any, any> = Component.current!;
   const store = options.store || (component.env.store as Store);
+  if (!(store instanceof Store)) {
+    throw new Error(`No store found when connecting '${component.constructor.name}'`);
+  }
   let result = selector(store.state, component.props);
   const hashFn = store.observer.revNumber.bind(store.observer);
   let revNumber = hashFn(result) || result;

tests/store_hooks.test.ts

@@ -48,6 +48,22 @@ describe("connecting a component to store", () => {
     expect(fixture.innerHTML).toBe("<div><span>hello</span></div>");
   });
 
+  test("throw error if no store is found", async () => {
+    class App extends Component<any, any> {
+      static template = xml`<div></div>`;
+      todos = useStore(state => state.todos);
+    }
+
+    let error;
+    try {
+      new App();
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeDefined();
+    expect(error.message).toBe("No store found when connecting 'App'");
+  });
+
   test("can use useStore twice in a component", async () => {
     const state = { a: 1, b: 2 };
     const actions = {