Modify healthcheck and server on-close to close database connection

backend/src/services/DatabaseService.ts

@@ -1,16 +1,32 @@
 import mongoose from 'mongoose';
 import { getLogger } from '../utils/logger';
-import { initDatabaseHelper } from '../helpers/database';
+import { 
+  initDatabaseHelper,
+  closeDatabaseHelper
+} from '../helpers/database';
 
 /**
  * Class to handle database actions
  */
 class DatabaseService {
+  /**
+   * Initialize database connection
+   * @param {Object} obj
+   * @param {String} obj.mongoURL - mongo connection string
+   * @returns 
+   */
   static async initDatabase(MONGO_URL: string) {
     return await initDatabaseHelper({
       mongoURL: MONGO_URL
     });
   }
+  
+  /**
+   * Close database conection
+  */
+  static async closeDatabase() {
+    return await closeDatabaseHelper();
+  }
 }
 
 export default DatabaseService;