Fix Vercel serverless deployment: Convert ES modules to CommonJS

package.json

@@ -32,12 +32,12 @@
     "server": "cd server && npm run dev",
     "dev": "concurrently -n \"CLIENT,SERVER\" -c \"bgBlue.bold,bgMagenta.bold\" \"npm run client\" \"npm run server\"",
     "prepare": "husky",
-    "lint": "cd client && npx eslint src --ext .ts,.tsx && cd ../server && npx eslint src --ext .js && cd ..",
-    "lint:fix": "cd client && npx eslint src --ext .ts,.tsx --fix && cd ../server && npx eslint src --ext .js --fix && cd ..",
-    "format": "prettier --write \"client/src/**/*.{ts,tsx,js,jsx,css,html}\" \"server/**/*.js\" \"*.{json,md,yml,yaml}\"",
-    "format:check": "prettier --check \"client/src/**/*.{ts,tsx,js,jsx,css,html}\" \"server/**/*.js\" \"*.{json,md,yml,yaml}\"",
+    "lint": "cd client && npx eslint src --ext .ts,.tsx && cd ../server && npx eslint src --ext .ts && cd ..",
+    "lint:fix": "cd client && npx eslint src --ext .ts,.tsx --fix && cd ../server && npx eslint src --ext .ts --fix && cd ..",
+    "format": "prettier --write \"client/src/**/*.{ts,tsx,js,jsx,css,html}\" \"server/**/*.ts\" \"*.{json,md,yml,yaml}\"",
+    "format:check": "prettier --check \"client/src/**/*.{ts,tsx,js,jsx,css,html}\" \"server/**/*.ts\" \"*.{json,md,yml,yaml}\"",
     "format:client": "prettier --write \"client/src/**/*.{ts,tsx,js,jsx,css,html}\"",
-    "format:server": "prettier --write \"server/**/*.js\"",
+    "format:server": "prettier --write \"server/**/*.ts\"",
     "format:docs": "prettier --write \"*.{json,md,yml,yaml}\"",
     "precommit-check": "npm run lint && npm run format:check",
     "docker:up": "docker-compose up -d",
@@ -74,7 +74,7 @@
       "prettier --write",
       "eslint --config client/eslint.config.js --fix"
     ],
-    "server/**/*.js": [
+    "server/**/*.ts": [
       "prettier --write",
       "eslint --fix"
     ],

server/DEPLOYMENT.md

@@ -0,0 +1,236 @@
+# 🚀 Vercel Deployment Guide for TypeScript Backend
+
+## Pre-Deployment Checklist
+
+✅ **TypeScript Compilation**: `npm run build` succeeds with 0 errors
+✅ **Entry Point**: `index.ts` exports Express app (no listen in production)
+✅ **Vercel Config**: `vercel.json` properly configured
+✅ **Dependencies**: All @types packages installed
+✅ **Environment Variables**: All required vars documented
+
+## Environment Variables Required
+
+Set these in Vercel Dashboard → Settings → Environment Variables:
+
+### Required Variables
+```
+PORT=8000
+NODE_ENV=production
+MONGODB_URL=<your-mongodb-connection-string>
+JWT_SECRET_ACCESS_KEY=<your-secure-access-key>
+JWT_SECRET_REFRESH_KEY=<your-secure-refresh-key>
+JWT_ACCESS_EXPIRES_IN=15m
+JWT_REFRESH_EXPIRES_IN=7d
+```
+
+### Optional Variables (with defaults)
+```
+SERVER_ENV=production
+VITE_SERVER_DOMAIN=<your-server-url>
+VITE_CLIENT_DOMAIN=<your-client-url>
+CLOUDINARY_CLOUD_NAME=<your-cloudinary-name>
+CLOUDINARY_API_KEY=<your-cloudinary-key>
+CLOUDINARY_API_SECRET=<your-cloudinary-secret>
+ADMIN_EMAIL=<admin-email>
+RESEND_API_KEY=<resend-api-key>
+```
+
+## Vercel Configuration
+
+**File**: `server/vercel.json`
+```json
+{
+  "version": 2,
+  "builds": [
+    {
+      "src": "dist/index.js",
+      "use": "@vercel/node"
+    }
+  ],
+  "routes": [
+    {
+      "src": "/(.*)",
+      "dest": "dist/index.js"
+    }
+  ]
+}
+```
+
+**Note**: The configuration points to the compiled `dist/index.js` file. Vercel will automatically run `npm run build` before deployment to compile TypeScript to JavaScript.
+
+## Build Settings in Vercel
+
+1. **Framework Preset**: Other
+2. **Root Directory**: `server`
+3. **Build Command**: `npm run build` (auto-detected from package.json)
+4. **Output Directory**: Leave empty (dist is part of the build)
+5. **Install Command**: `npm install`
+6. **Node Version**: 18.x or higher
+
+**Important**: 
+- Vercel will automatically run `npm run build` which compiles TypeScript to the `dist/` folder
+- The serverless function serves the compiled JavaScript from `dist/index.js`
+- TypeScript is compiled to CommonJS for compatibility with Vercel's Node.js runtime
+
+## Deployment Steps
+
+### Option 1: Vercel CLI
+
+```bash
+# Install Vercel CLI
+npm i -g vercel
+
+# Login to Vercel
+vercel login
+
+# Deploy
+cd server
+vercel --prod
+```
+
+### Option 2: Git Integration
+
+1. Push to GitHub/GitLab/Bitbucket
+2. Import project in Vercel
+3. Set root directory to `server`
+4. Configure environment variables
+5. Deploy
+
+## Post-Deployment Verification
+
+### 1. Check Health Endpoint
+```bash
+curl https://your-domain.vercel.app
+# Expected: {"status":"success","message":"Backend is running..."}
+```
+
+### 2. Check Monitor Endpoint
+```bash
+curl https://your-domain.vercel.app/monitor/health
+# Expected: {"status":"healthy","uptime":<seconds>,"database":"connected"}
+```
+
+### 3. Test API Endpoints
+```bash
+# Test authentication
+curl -X POST https://your-domain.vercel.app/api/auth/signup \
+  -H "Content-Type: application/json" \
+  -d '{"fullname":"Test User","email":"test@example.com","password":"Test123"}'
+```
+
+## Troubleshooting
+
+### Build Fails
+
+**Problem**: TypeScript compilation errors
+**Solution**:
+```bash
+cd server
+npm run build
+# Fix any errors shown
+```
+
+### Module Not Found
+
+**Problem**: Missing dependencies
+**Solution**:
+```bash
+npm install
+npm run build
+```
+
+### Database Connection Fails
+
+**Problem**: MongoDB connection string incorrect
+**Solution**: 
+- Verify MONGODB_URL in environment variables
+- Ensure MongoDB Atlas allows Vercel IPs
+- Check connection string format
+
+### JWT Errors
+
+**Problem**: Token verification fails
+**Solution**:
+- Verify JWT_SECRET_ACCESS_KEY is set
+- Ensure JWT_SECRET_REFRESH_KEY is set
+- Check token expiration settings
+
+### CORS Issues
+
+**Problem**: Frontend can't connect
+**Solution**:
+- Set VITE_CLIENT_DOMAIN in environment
+- Verify CORS configuration in server.ts
+- Check allowed origins
+
+## Monitoring
+
+### Vercel Dashboard
+- View logs in Vercel Dashboard → Deployments → Logs
+- Monitor function invocations
+- Check error rates
+
+### Application Logs
+The backend uses Winston logging:
+- Errors logged to console (viewable in Vercel)
+- HTTP requests logged with Morgan
+
+## Performance Tips
+
+### Cold Starts
+- First request after inactivity may be slow (~3-5s)
+- Subsequent requests are fast (<100ms)
+- Consider Vercel Pro for reduced cold starts
+
+### Database Connection
+- MongoDB connection is cached globally
+- Reused across function invocations
+- No connection pool exhaustion
+
+### Rate Limiting
+- Auth endpoints: Limited per IP
+- General endpoints: Limited per IP
+- Configured in middlewares
+
+## Scaling
+
+Vercel automatically scales based on:
+- Request volume
+- Geographic distribution
+- Time of day
+
+No manual scaling configuration needed.
+
+## Security Checklist
+
+✅ Environment variables in Vercel (not committed)
+✅ HTTPS enforced by Vercel
+✅ Rate limiting enabled
+✅ Input sanitization active
+✅ JWT authentication configured
+✅ Helmet security headers enabled
+✅ HPP protection enabled
+
+## Cost Considerations
+
+**Vercel Hobby Plan** (Free):
+- 100GB bandwidth
+- 100 function invocations per day
+- 10s max execution time
+- Good for development/testing
+
+**Vercel Pro Plan** ($20/month):
+- 1TB bandwidth
+- Unlimited function invocations
+- 60s max execution time
+- Production ready
+
+## Support
+
+- Vercel Documentation: https://vercel.com/docs
+- Vercel Support: https://vercel.com/support
+- GitHub Issues: https://github.com/Code-A2Z/code-a2z/issues
+
+---
+
+✅ **Ready for Production Deployment!**