refactored function into connectDB()

mongodb.js

-const { MongoClient, Db } = require('mongodb');
-const url = 'mongodb://localhost:27017/todo';
+const mongoose = require('mongoose');
 
-async function createCollections() {
-  	try {
-		const client = new MongoClient(url);
-		await client.connect();
+// Function to connect to MongoDB using Mongoose and create collections
+async function connectDB() {
+  try {
+    // Connect using the MongoDB URI from environment variables
+    const conn = await mongoose.connect("mongodb://127.0.0.1:27017");
+    console.log(`MongoDB connected: ${conn.connection.host}`);
 
-		// Check if the "todo" database exists and create it if not
-		const db = client.db('todo');
-		await db.createCollection('users'); // Check if collection "users" exists and create it if it doesn't exist
-		await db.createCollection('todos'); // Check if collection "todos" exists and create it if it doesn't exist
-		await db.createCollection('global'); // Check if collection "global" exists and create it if it doesn't exist
+    // Get the database object from the connection
+    const db = conn.connection.db;
 
-		console.log('Collections created successfully!');
-		await client.close();
-	} catch (error) {
-		console.error('Error creating collections:', error);
-	}
+    // Check if the collections exist and create them if not
+    await db.createCollection('users');
+    await db.createCollection('todos');
+    await db.createCollection('global');
+
+    console.log('Collections created successfully!');
+  } catch (err) {
+    console.error(`Error: ${err.message}`);
+    process.exit(1); // Exit the process with failure if the connection or collection creation fails
+  }
 }
 
-createCollections();
+module.exports = connectDB;
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