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Switched from raw promises to async/await.
Outlined error handling function to reduce amount of nested code.
Added comment about the new file intent.

server.js

@@ -79,7 +79,6 @@ const config = require('nconf')
 
 // DB
 const DB = require('./server/db.js');
-// FIXME: consider implementing error hanlding for a Promise returned by connect
 DB.connect(config);
 
 //Account Middleware

server/db.js

@@ -1,3 +1,10 @@
+// The main purpose of this file is to provide an interface for database
+// connection. Even though the code is quite simple and basically a tiny
+// wrapper around mongoose package, it works as single point where
+// database setup/config is performed and the interface provided here can be
+// reused by both the main application and all tests which require database
+// connection.
+
 const Mongoose = require('mongoose');
 
 const getMongoDBURL = (config)=>{
@@ -6,29 +13,22 @@ const getMongoDBURL = (config)=>{
            'mongodb://localhost/homebrewery';
 };
 
-const disconnect = ()=>{
-	return Mongoose.close();
+const handleConnectionError = (error)=>{
+	if(error) {
+		console.error('Could not connect to a Mongo database: \n');
+		console.error(error);
+		console.error('\nIf you are running locally, make sure mongodb.exe is running and DB URL is configured properly');
+		process.exit(1); // non-zero exit code to indicate an error
+	}
 };
 
-const connect = (config)=>{
-	const resolver = (resolve, reject)=>{
-		Mongoose.connect(getMongoDBURL(config),
-			{ retryWrites: false },
-			(error)=>{
-				if(error) {
-					console.error('Could not connect to a Mongo Database.');
-					console.log(error);
-					console.error('If you are running locally, make sure mongodb.exe is running.');
-					// FIXME: do we need to pass 'error' to 'reject'?
-					return reject();
-				}
+const disconnect = async ()=>{
+	return await Mongoose.disconnect();
+};
 
-				return resolve();
-			});
-
-	};
-
-	return new Promise(resolver);
+const connect = async (config)=>{
+	return await Mongoose.connect(getMongoDBURL(config),
+		{ retryWrites: false }, handleConnectionError);
 };
 
 module.exports = {