test: add tests for navbar-utils functions handleLogout and deleteAllTasks (#360)

Author: Anujsinghdevx

frontend/src/components/HomeComponents/Navbar/__tests__/navbar-utils.test.ts

@@ -1,7 +1,8 @@
 import { Task } from '@/components/utils/types';
 import { handleLogout, deleteAllTasks } from '../navbar-utils';
+import { toast } from 'react-toastify';
 
-// Mock external dependencies
+// Toast mock
 jest.mock('react-toastify', () => ({
   toast: {
     success: jest.fn(),
@@ -11,18 +12,29 @@ jest.mock('react-toastify', () => ({
   },
 }));
 
+// Dexie mock
 jest.mock('dexie', () => {
-  return jest.fn().mockImplementation(() => ({
+  const mockCount = jest.fn();
+  const mockDelete = jest.fn();
+
+  const DexieMock = jest.fn().mockImplementation(() => ({
     version: jest.fn().mockReturnThis(),
     stores: jest.fn().mockReturnThis(),
     table: jest.fn().mockReturnValue({
       where: jest.fn().mockReturnThis(),
       equals: jest.fn().mockReturnThis(),
-      delete: jest.fn().mockResolvedValue(undefined), // simulates delete success
+      count: mockCount,
+      delete: mockDelete,
     }),
   }));
+
+  return Object.assign(DexieMock, {
+    __mockCount: mockCount,
+    __mockDelete: mockDelete,
+  });
 });
 
+// URL mock
 jest.mock('@/components/utils/URLs.ts', () => ({
   url: {
     backendURL: 'http://localhost:3000/',
@@ -32,12 +44,26 @@ jest.mock('@/components/utils/URLs.ts', () => ({
 global.fetch = jest.fn();
 
 describe('navbar-utils', () => {
+  const mockToast = toast as jest.Mocked<typeof toast>;
+  const Dexie = require('dexie');
+  const mockCount = Dexie.__mockCount as jest.Mock;
+  const mockDelete = Dexie.__mockDelete as jest.Mock;
+
+  beforeAll(() => {
+    jest.spyOn(console, 'log').mockImplementation(() => {});
+    jest.spyOn(console, 'error').mockImplementation(() => {});
+  });
+
+  beforeEach(() => {
+    mockToast.info.mockReturnValue('toast-id' as any);
+  });
+
   afterEach(() => {
     jest.clearAllMocks();
   });
 
   describe('handleLogout', () => {
-    it('should call fetch with correct URL and redirect on success', async () => {
+    it('calls fetch with correct URL and redirects on success', async () => {
       (fetch as jest.Mock).mockResolvedValue({ ok: true });
 
       await handleLogout();
@@ -46,47 +72,78 @@ describe('navbar-utils', () => {
         method: 'POST',
         credentials: 'include',
       });
+
       expect(window.location.href).toBe('http://localhost/');
     });
 
-    it('should log an error if fetch fails', async () => {
-      const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation();
+    it('logs error when response is not ok', async () => {
+      const spy = jest.spyOn(console, 'error').mockImplementation();
 
       (fetch as jest.Mock).mockResolvedValue({ ok: false });
 
       await handleLogout();
 
-      expect(consoleErrorSpy).toHaveBeenCalledWith('Failed to logout');
-      consoleErrorSpy.mockRestore();
+      expect(spy).toHaveBeenCalledWith('Failed to logout');
+      spy.mockRestore();
     });
 
-    it('should log an error if fetch throws an exception', async () => {
-      const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation();
+    it('logs error when fetch throws exception', async () => {
+      const spy = jest.spyOn(console, 'error').mockImplementation();
 
       (fetch as jest.Mock).mockRejectedValue(new Error('Network error'));
 
       await handleLogout();
 
-      expect(consoleErrorSpy).toHaveBeenCalledWith(
-        'Error logging out:',
-        expect.any(Error)
-      );
-      consoleErrorSpy.mockRestore();
+      expect(spy).toHaveBeenCalledWith('Error logging out:', expect.any(Error));
+      spy.mockRestore();
     });
   });
 
   describe('deleteAllTasks', () => {
-    it('should delete tasks without error', async () => {
-      const props = {
-        imgurl: '',
-        email: 'test@example.com',
-        encryptionSecret: '',
-        origin: '',
-        UUID: '',
-        tasks: [] as Task[] | null,
-      };
-
-      await expect(deleteAllTasks(props)).resolves.toBeUndefined();
+    const props = {
+      imgurl: '',
+      email: 'test@example.com',
+      encryptionSecret: '',
+      origin: '',
+      UUID: '',
+      tasks: [] as Task[] | null,
+    };
+
+    it('shows error toast when no tasks exist', async () => {
+      mockCount.mockResolvedValueOnce(0);
+
+      await deleteAllTasks(props);
+
+      expect(mockToast.info).toHaveBeenCalled();
+      expect(mockToast.update).toHaveBeenCalledWith(
+        'toast-id',
+        expect.objectContaining({ type: 'error' })
+      );
+    });
+
+    it('deletes tasks and shows success toast when tasks exist', async () => {
+      mockCount.mockResolvedValueOnce(3);
+      mockDelete.mockResolvedValueOnce(undefined);
+
+      await deleteAllTasks(props);
+
+      expect(mockDelete).toHaveBeenCalled();
+      expect(mockToast.update).toHaveBeenCalledWith(
+        'toast-id',
+        expect.objectContaining({ type: 'success' })
+      );
+    });
+
+    it('shows error toast when deletion fails', async () => {
+      mockCount.mockResolvedValueOnce(2);
+      mockDelete.mockRejectedValueOnce(new Error('DB error'));
+
+      await deleteAllTasks(props);
+
+      expect(mockToast.update).toHaveBeenCalledWith(
+        'toast-id',
+        expect.objectContaining({ type: 'error' })
+      );
     });
   });
 });