Fix Zustand migration: type accuracy, perf optimization, and test completeness

src/App.tsx

@@ -111,13 +111,24 @@ function App() {
   // Sync state and actions from hooks into the zustand store so that
   // child components can subscribe to individual slices without a Provider.
   useEffect(() => {
-    useFormStore.setState({
+    const nextState = {
       username, startDate, endDate, githubToken, apiMode, searchText,
       loading, loadingProgress, error,
       searchItemsCount, eventsCount, rawEventsCount,
       setUsername, setStartDate, setEndDate, setGithubToken, setApiMode, setSearchText,
       handleSearch, validateUsernameFormat, addAvatarsToCache,
-    });
+    };
+    const currentState = useFormStore.getState() as typeof nextState;
+    const changedState = (Object.keys(nextState) as (keyof typeof nextState)[]).reduce(
+      (acc, key) => {
+        if (currentState[key] !== nextState[key]) acc[key] = nextState[key] as never;
+        return acc;
+      },
+      {} as Partial<typeof nextState>
+    );
+    if (Object.keys(changedState).length > 0) {
+      useFormStore.setState(changedState);
+    }
   }, [
     username, startDate, endDate, githubToken, apiMode, searchText,
     loading, loadingProgress, error,

src/components/__tests__/Summary.test.tsx

@@ -11,13 +11,16 @@ const mockFormStore = {
   endDate: '2024-01-31',
   username: 'testuser',
   apiMode: 'summary' as const,
+  searchText: '',
   setUsername: vi.fn(),
   setStartDate: vi.fn(),
   setEndDate: vi.fn(),
   setGithubToken: vi.fn(),
   setApiMode: vi.fn(),
+  setSearchText: vi.fn(),
   handleSearch: vi.fn(),
   validateUsernameFormat: vi.fn(),
+  addAvatarsToCache: vi.fn(),
   loading: false,
   loadingProgress: '',
   error: null,

src/store/useFormStore.ts

@@ -29,7 +29,7 @@ interface FormStoreActions {
   setGithubToken: (token: string) => void;
   setApiMode: (mode: ApiMode) => void;
   setSearchText: (text: string) => void;
-  handleSearch: () => void;
+  handleSearch: () => Promise<void>;
   validateUsernameFormat: (username: string) => void;
   addAvatarsToCache: (avatarUrls: { [username: string]: string }) => void;
 }
@@ -39,9 +39,9 @@ type FormStore = FormStoreState & FormStoreActions;
 /**
  * Zustand store replacing the former React Context (FormContext).
  *
- * State values and action callbacks are synced from App.tsx via
- * `useFormStoreSync` so that the existing hooks remain the source of truth
- * while consumers get fine-grained subscriptions without a Provider.
+ * State values and action callbacks are synced from App.tsx via a `useEffect`
+ * hook so that the existing hooks remain the source of truth while consumers
+ * get fine-grained subscriptions without a Provider.
  */
 const useFormStore = create<FormStore>()(() => ({
   // State defaults
@@ -65,7 +65,7 @@ const useFormStore = create<FormStore>()(() => ({
   setGithubToken: () => {},
   setApiMode: () => {},
   setSearchText: () => {},
-  handleSearch: () => {},
+  handleSearch: () => Promise.resolve(),
   validateUsernameFormat: () => {},
   addAvatarsToCache: () => {},
 }));