[#7] refactor: move mongoose connection logic into seperate util file

backend/user-service/src/common/mongodb.util.ts

@@ -0,0 +1,12 @@
+import { connect } from 'mongoose'
+import logger from './logger.util'
+
+export default async (connectionString: string): Promise<void> => {
+    await connect(connectionString)
+        .then(() => {
+            logger.info(`[Init] Connected to database`)
+        })
+        .catch((error: Error) => {
+            logger.error(`[Init] Failed to connect to database: ${error.message}`)
+        })
+}

backend/user-service/src/server.ts

@@ -1,25 +1,19 @@
 import 'dotenv/config'
 import http, { Server } from 'http'
-import { connect } from 'mongoose'
 import logger from './common/logger.util'
+import connectToDatabase from './common/mongodb.util'
 import index from './index'
 
 const port: string = process.env.PORT ?? '3000'
-const dbUrl: string | undefined = process.env.DB_URL
-if (!dbUrl) {
-    logger.error(`[Init] DB_URL is not set`)
-}
-
 const server: Server = http.createServer(index)
-
-connect(dbUrl!)
-    .then(() => {
-        logger.info(`[Init] Connected to MongoDB`)
-    })
-    .catch((error: Error) => {
-        logger.error(`[Init] ${error.message}`)
-    })
-
 server.listen(port, async () => {
     logger.info(`[Init] Server is listening on port ${port}`)
 })
+
+const connectionString: string | undefined = process.env.DB_URL
+if (!connectionString) {
+    logger.error(`[Init] DB_URL is not set`)
+    process.exit(1)
+}
+
+connectToDatabase(connectionString)