refactor: simplify async route handlers by making 'next' optional

src/pages/admin/components/SystemCheck.tsx

@@ -1,4 +1,5 @@
 // src/pages/admin/components/SystemCheck.tsx
+/// <reference types="vite/client" />
 import React, { useState, useEffect, useCallback } from 'react';
 import toast from 'react-hot-toast';
 import { loginUser, pingBackend, checkDbSchema, checkStorage, checkDbPoolHealth, checkPm2Status, checkRedisHealth, triggerFailingJob, clearGeocodeCache } from '../../../services/apiClient';

src/routes/admin.ts

@@ -7,6 +7,7 @@ import multer from 'multer';
 import * as db from '../services/db';
 import { logger } from '../services/logger.server';
 import { UserProfile } from '../types';
+import { AsyncRequestHandler } from '../types/express';
 import { clearGeocodeCache } from '../services/geocodingService.server';
 
 // --- Bull Board (Job Queue UI) Imports ---
@@ -55,27 +56,27 @@ router.use(passport.authenticate('jwt', { session: false }), isAdmin);
 
 // --- Admin Routes ---
 
-router.get('/corrections', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/corrections', async (req, res, next) => {
     const corrections = await db.getSuggestedCorrections();
     res.json(corrections);
 });
 
-router.get('/brands', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/brands', async (req, res, next) => {
     const brands = await db.getAllBrands();
     res.json(brands);
 });
 
-router.get('/stats', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/stats', async (req, res, next) => {
     const stats = await db.getApplicationStats();
     res.json(stats);
 });
 
-router.get('/stats/daily', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/stats/daily', async (req, res, next) => {
     const dailyStats = await db.getDailyStatsForLast30Days();
     res.json(dailyStats);
 });
 
-router.post('/corrections/:id/approve', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/corrections/:id/approve', async (req, res, next) => {
     const correctionId = parseInt(req.params.id, 10);
     // Add validation to ensure the ID is a valid number.
     if (isNaN(correctionId)) {
@@ -86,13 +87,13 @@ router.post('/corrections/:id/approve', async (req: Request, res: Response, next
     res.status(200).json({ message: 'Correction approved successfully.' });
 });
 
-router.post('/corrections/:id/reject', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/corrections/:id/reject', async (req, res, next) => {
     const correctionId = parseInt(req.params.id, 10);
     await db.rejectCorrection(correctionId);
     res.status(200).json({ message: 'Correction rejected successfully.' });
 });
 
-router.put('/corrections/:id', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/corrections/:id', async (req, res, next) => {
     const correctionId = parseInt(req.params.id, 10);
     const { suggested_value } = req.body;
     if (!suggested_value) {
@@ -110,7 +111,7 @@ router.put('/corrections/:id', async (req: Request, res: Response, next: NextFun
     }
 });
 
-router.put('/recipes/:id/status', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/recipes/:id/status', async (req, res, next) => {
     const recipeId = parseInt(req.params.id, 10);
     const { status } = req.body;
 
@@ -121,7 +122,7 @@ router.put('/recipes/:id/status', async (req: Request, res: Response, next: Next
     res.status(200).json(updatedRecipe);
 });
 
-router.post('/brands/:id/logo', upload.single('logoImage'), async (req: Request, res: Response, next: NextFunction) => {
+router.post('/brands/:id/logo', upload.single('logoImage'), async (req, res, next) => {
     const brandId = parseInt(req.params.id, 10);
     if (!req.file) {
         return res.status(400).json({ message: 'Logo image file is required.' });
@@ -134,12 +135,12 @@ router.post('/brands/:id/logo', upload.single('logoImage'), async (req: Request,
     res.status(200).json({ message: 'Brand logo updated successfully.', logoUrl });
 });
 
-router.get('/unmatched-items', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/unmatched-items', async (req, res, next) => {
     const items = await db.getUnmatchedFlyerItems();
     res.json(items);
 });
 
-router.put('/comments/:id/status', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/comments/:id/status', async (req, res, next) => {
     const commentId = parseInt(req.params.id, 10);
     const { status } = req.body;
 
@@ -150,19 +151,19 @@ router.put('/comments/:id/status', async (req: Request, res: Response, next: Nex
     res.status(200).json(updatedComment);
 });
 
-router.get('/users', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/users', async (req, res, next) => {
     const users = await db.getAllUsers();
     res.json(users);
 });
 
-router.get('/activity-log', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/activity-log', async (req, res, next) => {
     const limit = parseInt(req.query.limit as string, 10) || 50;
     const offset = parseInt(req.query.offset as string, 10) || 0;
     const logs = await db.getActivityLog(limit, offset);
     res.json(logs);
 });
 
-router.get('/users/:id', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/users/:id', async (req, res, next) => {
     const user = await db.findUserProfileById(req.params.id);
     if (!user) {
         return res.status(404).json({ message: 'User not found.' });
@@ -170,7 +171,7 @@ router.get('/users/:id', async (req: Request, res: Response, next: NextFunction)
     res.json(user);
 });
 
-router.put('/users/:id', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/users/:id', async (req, res, next) => {
     const { role } = req.body;
     if (!role || !['user', 'admin'].includes(role)) {
         return res.status(400).json({ message: 'A valid role ("user" or "admin") is required.' });
@@ -189,7 +190,7 @@ router.put('/users/:id', async (req: Request, res: Response, next: NextFunction)
     }
 });
 
-router.delete('/users/:id', async (req: Request, res: Response, next: NextFunction) => {
+router.delete('/users/:id', async (req, res, next) => {
     const adminUser = req.user as UserProfile;
     if (adminUser.user.user_id === req.params.id) {
         return res.status(400).json({ message: 'Admins cannot delete their own account.' });
@@ -202,7 +203,7 @@ router.delete('/users/:id', async (req: Request, res: Response, next: NextFuncti
  * POST /api/admin/trigger/daily-deal-check - Manually trigger the daily deal check job.
  * This is useful for testing or forcing an update without waiting for the cron schedule.
  */
-router.post('/trigger/daily-deal-check', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/trigger/daily-deal-check', async (req, res, next) => {
     const adminUser = req.user as UserProfile;
     logger.info(`[Admin] Manual trigger for daily deal check received from user: ${adminUser.user_id}`);
 
@@ -221,7 +222,7 @@ router.post('/trigger/daily-deal-check', async (req: Request, res: Response, nex
  * POST /api/admin/trigger/analytics-report - Manually enqueue a job to generate the daily analytics report.
  * This is useful for testing or re-generating a report without waiting for the cron schedule.
  */
-router.post('/trigger/analytics-report', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/trigger/analytics-report', async (req, res, next) => {
     const adminUser = req.user as UserProfile;
     logger.info(`[Admin] Manual trigger for analytics report generation received from user: ${adminUser.user_id}`);
 
@@ -243,7 +244,7 @@ router.post('/trigger/analytics-report', async (req: Request, res: Response, nex
  * POST /api/admin/flyers/:flyerId/cleanup - Enqueue a job to clean up a flyer's files.
  * This is triggered by an admin after they have verified the flyer processing was successful.
  */
-router.post('/flyers/:flyerId/cleanup', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/flyers/:flyerId/cleanup', async (req, res, next) => {
     const adminUser = req.user as UserProfile;
     const flyerId = parseInt(req.params.flyerId, 10);
 
@@ -262,7 +263,7 @@ router.post('/flyers/:flyerId/cleanup', async (req: Request, res: Response, next
  * POST /api/admin/trigger/failing-job - Enqueue a test job designed to fail.
  * This is for testing the retry mechanism and Bull Board UI.
  */
-router.post('/trigger/failing-job', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/trigger/failing-job', async (req, res, next) => {
     const adminUser = req.user as UserProfile;
     logger.info(`[Admin] Manual trigger for a failing job received from user: ${adminUser.user_id}`);
 
@@ -279,7 +280,7 @@ router.post('/trigger/failing-job', async (req: Request, res: Response, next: Ne
  * POST /api/admin/system/clear-geocode-cache - Clears the Redis cache for geocoded addresses.
  * Requires admin privileges.
  */
-router.post('/system/clear-geocode-cache', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/system/clear-geocode-cache', async (req, res, next) => {
     const adminUser = req.user as UserProfile;
     logger.info(`[Admin] Manual trigger for geocode cache clear received from user: ${adminUser.user_id}`);
 

src/routes/ai.ts

@@ -10,6 +10,7 @@ import * as aiService from '../services/aiService.server'; // Correctly import s
 import { generateFlyerIcon } from '../utils/imageProcessor';
 import { logger } from '../services/logger.server';
 import { UserProfile } from '../types';
+import { AsyncRequestHandler } from '../types/express';
 import { flyerQueue } from '../services/queueService.server';
 
 const router = Router();
@@ -68,7 +69,7 @@ router.use((req: Request, res: Response, next: NextFunction) => {
  * NEW ENDPOINT: Accepts a single flyer file (PDF or image), enqueues it for
  * background processing, and immediately returns a job ID.
  */
-router.post('/upload-and-process', optionalAuth, uploadToDisk.single('flyerFile'), async (req: Request, res: Response, next: NextFunction) => {
+router.post('/upload-and-process', optionalAuth, uploadToDisk.single('flyerFile'), async (req, res, next) => {
     try {
         if (!req.file) {
             return res.status(400).json({ message: 'A flyer file (PDF or image) is required.' });
@@ -153,7 +154,7 @@ router.get('/jobs/:jobId/status', async (req, res) => {
  * in the flyer upload workflow after the AI has extracted the data.
  * It uses `optionalAuth` to handle submissions from both anonymous and authenticated users.
  */
-router.post('/flyers/process', optionalAuth, uploadToDisk.single('flyerImage'), async (req: Request, res: Response, next: NextFunction) => {
+router.post('/flyers/process', optionalAuth, uploadToDisk.single('flyerImage'), async (req, res, next) => {
     try {
         if (!req.file) {
             return res.status(400).json({ message: 'Flyer image file is required.' });
@@ -389,7 +390,7 @@ router.post(
     '/rescan-area',
     passport.authenticate('jwt', { session: false }),
     uploadToDisk.single('image'),
-    async (req: Request, res: Response, next: NextFunction) => {
+    async (req, res, next) => {
         try {
             if (!req.file) {
                 return res.status(400).json({ message: 'Image file is required.' });

src/routes/auth.ts

@@ -10,6 +10,7 @@ import passport from './passport';
 import * as db from '../services/db';
 import { getPool } from '../services/db/connection';
 import { logger } from '../services/logger.server';
+import { AsyncRequestHandler } from '../types/express';
 import { sendPasswordResetEmail } from '../services/emailService.server';
 
 const router = Router();
@@ -41,7 +42,7 @@ const resetPasswordLimiter = rateLimit({
 // --- Authentication Routes ---
 
 // Registration Route
-router.post('/register', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/register', async (req, res, next) => {
   const { email, password, full_name, avatar_url } = req.body;
 
   if (!email || !password) {
@@ -146,7 +147,7 @@ router.post('/login', (req: Request, res: Response, next: NextFunction) => {
 });
 
 // Route to request a password reset
-router.post('/forgot-password', forgotPasswordLimiter, async (req: Request, res: Response, next: NextFunction) => {
+router.post('/forgot-password', forgotPasswordLimiter, async (req, res, next) => {
   const { email } = req.body;
   if (!email) {
     return res.status(400).json({ message: 'Email is required.' });
@@ -189,7 +190,7 @@ router.post('/forgot-password', forgotPasswordLimiter, async (req: Request, res:
 });
 
 // Route to reset the password using a token
-router.post('/reset-password', resetPasswordLimiter, async (req: Request, res: Response, next: NextFunction) => {
+router.post('/reset-password', resetPasswordLimiter, async (req, res, next) => {
   const { token, newPassword } = req.body;
   if (!token || !newPassword) {
     return res.status(400).json({ message: 'Token and new password are required.' });

src/routes/budget.ts

@@ -10,6 +10,7 @@ import {
 } from '../services/db';
 import { logger } from '../services/logger.server';
 import { UserProfile } from '../types';
+import { AsyncRequestHandler } from '../types/express';
 
 const router = express.Router();
 
@@ -19,7 +20,7 @@ router.use(passport.authenticate('jwt', { session: false }));
 /**
  * GET /api/budgets - Get all budgets for the authenticated user.
  */
-router.get('/', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/', async (req, res, next) => {
   const user = req.user as UserProfile;
   try {
     const budgets = await getBudgetsForUser(user.user_id);
@@ -33,7 +34,7 @@ router.get('/', async (req: Request, res: Response, next: NextFunction) => {
 /**
  * POST /api/budgets - Create a new budget for the authenticated user.
  */
-router.post('/', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/', async (req, res, next) => {
   const user = req.user as UserProfile;
   try {
     const newBudget = await createBudget(user.user_id, req.body);
@@ -47,7 +48,7 @@ router.post('/', async (req: Request, res: Response, next: NextFunction) => {
 /**
  * PUT /api/budgets/:id - Update an existing budget.
  */
-router.put('/:id', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/:id', async (req, res, next) => {
   const user = req.user as UserProfile;
   const budgetId = parseInt(req.params.id, 10);
   try {
@@ -62,7 +63,7 @@ router.put('/:id', async (req: Request, res: Response, next: NextFunction) => {
 /**
  * DELETE /api/budgets/:id - Delete a budget.
  */
-router.delete('/:id', async (req: Request, res: Response, next: NextFunction) => {
+router.delete('/:id', async (req, res, next) => {
   const user = req.user as UserProfile;
   const budgetId = parseInt(req.params.id, 10);
   try {
@@ -78,7 +79,7 @@ router.delete('/:id', async (req: Request, res: Response, next: NextFunction) =>
  * GET /api/spending-analysis - Get spending breakdown by category for a date range.
  * Query params: startDate (YYYY-MM-DD), endDate (YYYY-MM-DD)
  */
-router.get('/spending-analysis', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/spending-analysis', async (req, res, next) => {
   const user = req.user as UserProfile;
   const { startDate, endDate } = req.query;
 

src/routes/gamification.ts

@@ -4,6 +4,7 @@ import passport, { isAdmin } from './passport';
 import { getAllAchievements, getUserAchievements, awardAchievement, getLeaderboard } from '../services/db';
 import { logger } from '../services/logger.server';
 import { UserProfile } from '../types';
+import { AsyncRequestHandler } from '../types/express';
 
 const router = express.Router();
 
@@ -11,7 +12,7 @@ const router = express.Router();
  * GET /api/achievements - Get the master list of all available achievements.
  * This is a public endpoint.
  */
-router.get('/', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/', async (req, res, next) => {
   try {
     const achievements = await getAllAchievements();
     res.json(achievements);
@@ -25,7 +26,7 @@ router.get('/', async (req: Request, res: Response, next: NextFunction) => {
  * GET /api/achievements/leaderboard - Get the top users by points.
  * This is a public endpoint.
  */
-router.get('/leaderboard', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/leaderboard', async (req, res, next) => {
   // Allow client to specify a limit, but default to 10 and cap it at 50.
   const limit = Math.min(parseInt(req.query.limit as string, 10) || 10, 50);
 
@@ -45,7 +46,7 @@ router.get('/leaderboard', async (req: Request, res: Response, next: NextFunctio
 router.get(
   '/me',
   passport.authenticate('jwt', { session: false }),
-  async (req: Request, res: Response, next: NextFunction) => {
+  async (req, res, next) => {
     const user = req.user as UserProfile;
     try {
       const userAchievements = await getUserAchievements(user.user_id);
@@ -65,7 +66,7 @@ router.post(
   '/award',
   passport.authenticate('jwt', { session: false }),
   isAdmin,
-  async (req: Request, res: Response, next: NextFunction) => {
+  async (req, res, next) => {
     const { userId, achievementName } = req.body;
 
     if (!userId || !achievementName) {

src/routes/public.ts

@@ -4,6 +4,7 @@ import * as db from '../services/db';
 import { logger } from '../services/logger.server';
 import fs from 'fs/promises';
 import passport from 'passport';
+import { AsyncRequestHandler } from '../types/express';
 
 const router = Router();
 
@@ -12,7 +13,7 @@ router.get('/health/ping', (req: Request, res: Response) => {
     res.status(200).send('pong');
 });
 
-router.get('/health/db-schema', async (req: Request, res: Response) => {
+router.get('/health/db-schema', async (req, res) => {
     try {
         const requiredTables = ['users', 'profiles', 'flyers', 'flyer_items', 'stores'];
         const missingTables = await db.checkTablesExist(requiredTables);
@@ -27,7 +28,7 @@ router.get('/health/db-schema', async (req: Request, res: Response) => {
     }
 });
 
-router.get('/health/storage', async (req: Request, res: Response) => {
+router.get('/health/storage', async (req, res) => {
     const storagePath = process.env.STORAGE_PATH || '/var/www/flyer-crawler.projectium.com/assets';
     try {
         await fs.access(storagePath, fs.constants.W_OK);
@@ -58,7 +59,7 @@ router.get('/health/db-pool', (req: Request, res: Response) => {
 
 // --- Public Data Routes ---
 
-router.get('/flyers', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/flyers', async (req, res, next) => {
     try {
         const flyers = await db.getFlyers();
         res.json(flyers);
@@ -68,7 +69,7 @@ router.get('/flyers', async (req: Request, res: Response, next: NextFunction) =>
     }
 });
 
-router.get('/master-items', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/master-items', async (req, res, next) => {
     try {
         const masterItems = await db.getAllMasterItems();
         res.json(masterItems);
@@ -78,7 +79,7 @@ router.get('/master-items', async (req: Request, res: Response, next: NextFuncti
     }
 });
 
-router.get('/flyers/:id/items', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/flyers/:id/items', async (req, res, next) => {
     try {
         const flyerId = parseInt(req.params.id, 10);
         const items = await db.getFlyerItems(flyerId);
@@ -89,7 +90,7 @@ router.get('/flyers/:id/items', async (req: Request, res: Response, next: NextFu
     }
 });
 
-router.post('/flyer-items/batch-fetch', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/flyer-items/batch-fetch', async (req, res, next) => {
     const { flyerIds } = req.body;
     if (!Array.isArray(flyerIds)) {
         return res.status(400).json({ message: 'flyerIds must be an array.' });
@@ -102,7 +103,7 @@ router.post('/flyer-items/batch-fetch', async (req: Request, res: Response, next
     }
 });
 
-router.post('/flyer-items/batch-count', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/flyer-items/batch-count', async (req, res, next) => {
     const { flyerIds } = req.body;
     if (!Array.isArray(flyerIds)) {
         return res.status(400).json({ message: 'flyerIds must be an array.' });
@@ -115,7 +116,7 @@ router.post('/flyer-items/batch-count', async (req: Request, res: Response, next
     }
 });
 
-router.get('/recipes/by-sale-percentage', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/recipes/by-sale-percentage', async (req, res, next) => {
     const minPercentageStr = req.query.minPercentage as string || '50.0';
     const minPercentage = parseFloat(minPercentageStr);
 
@@ -130,7 +131,7 @@ router.get('/recipes/by-sale-percentage', async (req: Request, res: Response, ne
     }
 });
 
-router.get('/recipes/by-sale-ingredients', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/recipes/by-sale-ingredients', async (req, res, next) => {
     const minIngredientsStr = req.query.minIngredients as string || '3';
     const minIngredients = parseInt(minIngredientsStr, 10);
 
@@ -141,7 +142,7 @@ router.get('/recipes/by-sale-ingredients', async (req: Request, res: Response, n
     res.json(recipes);
 });
 
-router.get('/recipes/by-ingredient-and-tag', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/recipes/by-ingredient-and-tag', async (req, res, next) => {
     const { ingredient, tag } = req.query;
     if (!ingredient || !tag) {
         return res.status(400).json({ message: 'Both "ingredient" and "tag" query parameters are required.' });
@@ -150,7 +151,7 @@ router.get('/recipes/by-ingredient-and-tag', async (req: Request, res: Response,
     res.json(recipes);
 });
 
-router.get('/stats/most-frequent-sales', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/stats/most-frequent-sales', async (req, res, next) => {
     const daysStr = req.query.days as string || '30';
     const limitStr = req.query.limit as string || '10';
 
@@ -168,18 +169,18 @@ router.get('/stats/most-frequent-sales', async (req: Request, res: Response, nex
     res.json(items);
 });
 
-router.get('/recipes/:recipeId/comments', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/recipes/:recipeId/comments', async (req, res, next) => {
     const recipeId = parseInt(req.params.recipeId, 10);
     const comments = await db.getRecipeComments(recipeId);
     res.json(comments);
 });
 
-router.get('/dietary-restrictions', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/dietary-restrictions', async (req, res, next) => {
     const restrictions = await db.getDietaryRestrictions();
     res.json(restrictions);
 });
 
-router.get('/appliances', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/appliances', async (req, res, next) => {
     const appliances = await db.getAppliances();
     res.json(appliances);
 });

src/routes/user.ts

@@ -9,6 +9,7 @@ import zxcvbn from 'zxcvbn';
 import * as db from '../services/db';
 import { logger } from '../services/logger.server';
 import { User, UserProfile, Address } from '../types';
+import { AsyncRequestHandler } from '../types/express';
 
 const router = express.Router();
 
@@ -27,7 +28,7 @@ fs.mkdir(avatarUploadDir, { recursive: true }).catch(err => {
  */
 router.post(
   '/profile/avatar',
-  async (req: Request, res: Response, next: NextFunction) => {
+  async (req, res, next) => {
     // Initialize multer inside the route handler where req.user is available.
     // This prevents the "Cannot read properties of undefined" error during test setup.
     const storage = multer.diskStorage({
@@ -120,7 +121,7 @@ router.post(
 /**
  * GET /api/users/profile - Get the full profile for the authenticated user.
  */
-router.get('/profile', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/profile', async (req, res, next) => {
   logger.debug(`[ROUTE] GET /api/users/profile - ENTER`);
   const user = req.user as UserProfile;
   try {
@@ -140,7 +141,7 @@ router.get('/profile', async (req: Request, res: Response, next: NextFunction) =
 /**
  * PUT /api/users/profile - Update the user's profile information.
  */
-router.put('/profile', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/profile', async (req, res, next) => {
   logger.debug(`[ROUTE] PUT /api/users/profile - ENTER`);
   const user = req.user as UserProfile;
   const { full_name, avatar_url } = req.body;
@@ -161,7 +162,7 @@ router.put('/profile', async (req: Request, res: Response, next: NextFunction) =
 /**
  * PUT /api/users/profile/password - Update the user's password.
  */
-router.put('/profile/password', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/profile/password', async (req, res, next) => {
   logger.debug(`[ROUTE] PUT /api/users/profile/password - ENTER`);
   const user = req.user as UserProfile;
   const { newPassword } = req.body;
@@ -191,7 +192,7 @@ router.put('/profile/password', async (req: Request, res: Response, next: NextFu
 /**
  * DELETE /api/users/account - Delete the user's own account.
  */
-router.delete('/account', async (req: Request, res: Response, next: NextFunction) => {
+router.delete('/account', async (req, res, next) => {
   logger.debug(`[ROUTE] DELETE /api/users/account - ENTER`);
   const user = req.user as UserProfile;
   const { password } = req.body;
@@ -222,7 +223,7 @@ router.delete('/account', async (req: Request, res: Response, next: NextFunction
 /**
  * GET /api/users/watched-items - Get all watched items for the authenticated user.
  */
-router.get('/watched-items', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/watched-items', async (req, res, next) => {
   logger.debug(`[ROUTE] GET /api/users/watched-items - ENTER`);
   const user = req.user as UserProfile;
   try {
@@ -237,7 +238,7 @@ router.get('/watched-items', async (req: Request, res: Response, next: NextFunct
 /**
  * POST /api/users/watched-items - Add a new item to the user's watchlist.
  */
-router.post('/watched-items', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/watched-items', async (req, res, next) => {
   logger.debug(`[ROUTE] POST /api/users/watched-items - ENTER`);
   const user = req.user as UserProfile;
   const { itemName, category } = req.body;
@@ -253,7 +254,7 @@ router.post('/watched-items', async (req: Request, res: Response, next: NextFunc
 /**
  * DELETE /api/users/watched-items/:masterItemId - Remove an item from the watchlist.
  */
-router.delete('/watched-items/:masterItemId', async (req: Request, res: Response, next: NextFunction) => {
+router.delete('/watched-items/:masterItemId', async (req, res, next) => {
   logger.debug(`[ROUTE] DELETE /api/users/watched-items/:masterItemId - ENTER`);
   const user = req.user as UserProfile;
   const masterItemId = parseInt(req.params.masterItemId, 10);
@@ -269,7 +270,7 @@ router.delete('/watched-items/:masterItemId', async (req: Request, res: Response
 /**
  * GET /api/users/shopping-lists - Get all shopping lists for the user.
  */
-router.get('/shopping-lists', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/shopping-lists', async (req, res, next) => {
   logger.debug(`[ROUTE] GET /api/users/shopping-lists - ENTER`);
   const user = req.user as UserProfile;
   try {
@@ -284,7 +285,7 @@ router.get('/shopping-lists', async (req: Request, res: Response, next: NextFunc
 /**
  * POST /api/users/shopping-lists - Create a new shopping list.
  */
-router.post('/shopping-lists', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/shopping-lists', async (req, res, next) => {
   logger.debug(`[ROUTE] POST /api/users/shopping-lists - ENTER`);
   const user = req.user as UserProfile;
   const { name } = req.body;
@@ -300,7 +301,7 @@ router.post('/shopping-lists', async (req: Request, res: Response, next: NextFun
 /**
  * DELETE /api/users/shopping-lists/:listId - Delete a shopping list.
  */
-router.delete('/shopping-lists/:listId', async (req: Request, res: Response, next: NextFunction) => {
+router.delete('/shopping-lists/:listId', async (req, res, next) => {
   logger.debug(`[ROUTE] DELETE /api/users/shopping-lists/:listId - ENTER`);
   const user = req.user as UserProfile;
   const listId = parseInt(req.params.listId, 10);
@@ -316,7 +317,7 @@ router.delete('/shopping-lists/:listId', async (req: Request, res: Response, nex
 /**
  * POST /api/users/shopping-lists/:listId/items - Add an item to a shopping list.
  */
-router.post('/shopping-lists/:listId/items', async (req: Request, res: Response, next: NextFunction) => {
+router.post('/shopping-lists/:listId/items', async (req, res, next) => {
   logger.debug(`[ROUTE] POST /api/users/shopping-lists/:listId/items - ENTER`);
   const listId = parseInt(req.params.listId, 10);
   try {
@@ -331,7 +332,7 @@ router.post('/shopping-lists/:listId/items', async (req: Request, res: Response,
 /**
  * PUT /api/users/shopping-lists/items/:itemId - Update a shopping list item.
  */
-router.put('/shopping-lists/items/:itemId', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/shopping-lists/items/:itemId', async (req, res, next) => {
   logger.debug(`[ROUTE] PUT /api/users/shopping-lists/items/:itemId - ENTER`);
   const itemId = parseInt(req.params.itemId, 10);
   try {
@@ -346,7 +347,7 @@ router.put('/shopping-lists/items/:itemId', async (req: Request, res: Response,
 /**
  * DELETE /api/users/shopping-lists/items/:itemId - Remove an item from a shopping list.
  */
-router.delete('/shopping-lists/items/:itemId', async (req: Request, res: Response, next: NextFunction) => {
+router.delete('/shopping-lists/items/:itemId', async (req, res, next) => {
   logger.debug(`[ROUTE] DELETE /api/users/shopping-lists/items/:itemId - ENTER`);
   const itemId = parseInt(req.params.itemId, 10);
   try {
@@ -361,7 +362,7 @@ router.delete('/shopping-lists/items/:itemId', async (req: Request, res: Respons
 /**
  * PUT /api/users/profile/preferences - Update user preferences.
  */
-router.put('/profile/preferences', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/profile/preferences', async (req, res, next) => {
   logger.debug(`[ROUTE] PUT /api/users/profile/preferences - ENTER`);
   const user = req.user as UserProfile;
   if (typeof req.body !== 'object' || req.body === null || Array.isArray(req.body)) {
@@ -376,7 +377,7 @@ router.put('/profile/preferences', async (req: Request, res: Response, next: Nex
   }
 });
 
-router.get('/me/dietary-restrictions', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/me/dietary-restrictions', async (req, res, next) => {
   logger.debug(`[ROUTE] GET /api/users/me/dietary-restrictions - ENTER`);
   const user = req.user as UserProfile;
   try {
@@ -388,7 +389,7 @@ router.get('/me/dietary-restrictions', async (req: Request, res: Response, next:
   }
 });
 
-router.put('/me/dietary-restrictions', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/me/dietary-restrictions', async (req, res, next) => {
   logger.debug(`[ROUTE] PUT /api/users/me/dietary-restrictions - ENTER`);
   const user = req.user as UserProfile;
   const { restrictionIds } = req.body;
@@ -401,7 +402,7 @@ router.put('/me/dietary-restrictions', async (req: Request, res: Response, next:
   }
 });
 
-router.get('/me/appliances', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/me/appliances', async (req, res, next) => {
   logger.debug(`[ROUTE] GET /api/users/me/appliances - ENTER`);
   const user = req.user as UserProfile;
   try {
@@ -413,7 +414,7 @@ router.get('/me/appliances', async (req: Request, res: Response, next: NextFunct
   }
 });
 
-router.put('/me/appliances', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/me/appliances', async (req, res, next) => {
   logger.debug(`[ROUTE] PUT /api/users/me/appliances - ENTER`);
   const user = req.user as UserProfile;
   const { applianceIds } = req.body;
@@ -430,7 +431,7 @@ router.put('/me/appliances', async (req: Request, res: Response, next: NextFunct
  * GET /api/users/addresses/:addressId - Get a specific address by its ID.
  * This is protected to ensure a user can only fetch their own address details.
  */
-router.get('/addresses/:addressId', async (req: Request, res: Response, next: NextFunction) => {
+router.get('/addresses/:addressId', async (req, res, next) => {
     const user = req.user as UserProfile;
     const addressId = parseInt(req.params.addressId, 10);
 
@@ -453,7 +454,7 @@ router.get('/addresses/:addressId', async (req: Request, res: Response, next: Ne
 /**
  * PUT /api/users/profile/address - Create or update the user's primary address.
  */
-router.put('/profile/address', async (req: Request, res: Response, next: NextFunction) => {
+router.put('/profile/address', async (req, res, next) => {
     const user = req.user as UserProfile;
     const addressData = req.body as Partial<Address>;
 

src/services/db/connection.test.ts

@@ -25,8 +25,6 @@ describe('DB Connection Service', () => {
     
     if (typeof pg.Pool === 'function') {
       try {
-        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-        // @ts-ignore
         const instance = new pg.Pool();
         console.log('[DEBUG] connection.test.ts: new pg.Pool() SUCCESS. Instance:', Object.keys(instance));
       } catch (e) {

src/services/express.d.ts

@@ -0,0 +1,20 @@
+// src/types/express.d.ts
+import { Request, Response, NextFunction, RequestHandler } from 'express';
+
+/**
+ * Defines a more accurate type for asynchronous Express route handlers.
+ * Standard `RequestHandler` requires `next` to be present, which is often unused
+ * in modern async/await handlers, leading to linting errors. This type makes `next` optional.
+ *
+ * It also allows for more specific typing of the request body, query, and params.
+ */
+export type AsyncRequestHandler<
+  P = Record<string, string>,
+  ResBody = any,
+  ReqBody = any,
+  ReqQuery = qs.ParsedQs
+> = (
+  req: Request<P, ResBody, ReqBody, ReqQuery>,
+  res: Response<ResBody>,
+  next?: NextFunction
+) => Promise<void | unknown>;

src/types/express.d.ts

@@ -0,0 +1,20 @@
+// src/types/express.d.ts
+import { Request, Response, NextFunction, RequestHandler } from 'express';
+
+/**
+ * Defines a more accurate type for asynchronous Express route handlers.
+ * Standard `RequestHandler` requires `next` to be present, which is often unused
+ * in modern async/await handlers, leading to linting errors. This type makes `next` optional.
+ *
+ * It also allows for more specific typing of the request body, query, and params.
+ */
+export type AsyncRequestHandler<
+  P = Record<string, string>,
+  ResBody = any,
+  ReqBody = any,
+  ReqQuery = qs.ParsedQs
+> = (
+  req: Request<P, ResBody, ReqBody, ReqQuery>,
+  res: Response<ResBody>,
+  next?: NextFunction
+) => Promise<void | unknown>;

tsconfig.json

@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     "target": "ES2022",
+    "typeRoots": ["./node_modules/@types", "./src/types"],
     "experimentalDecorators": true,
     "useDefineForClassFields": false,
     "module": "ESNext",