made some basic structure changes and made some tests too

package.json

@@ -4,12 +4,11 @@
   "description": "A basic Express application with PostgreSQL integration.",
   "main": "app.js",
   "scripts": {
-    "start": "node app.js",
     "dev": "nodemon app.js",
     "lint": "eslint .",
     "lint:fix": "eslint . --fix",
-    "format": "prettier --config prettier.config.js --write .",
-    "migrate": "node-pg-migrate"
+    "migrate": "node-pg-migrate",
+    "test": "jest --forceExit"
   },
   "type": "module",
   "keywords": [
@@ -34,6 +33,9 @@
     "pg": "^8.20.0"
   },
   "devDependencies": {
+    "@babel/core": "^7.29.0",
+    "@babel/preset-env": "^7.29.5",
+    "babel-jest": "^30.4.1",
     "eslint": "^10.3.0",
     "eslint-config-prettier": "^10.1.8",
     "eslint-plugin-import": "^2.32.0",
@@ -41,6 +43,7 @@
     "jest": "^29.0.0",
     "node-pg-migrate": "^8.0.4",
     "nodemon": "^3.0.0",
-    "prettier": "^3.8.3"
+    "prettier": "^3.8.3",
+    "supertest": "^7.2.2"
   }
 }