init dart api server with mysql connection

bin/mess_api.dart

@@ -0,0 +1,51 @@
+import 'dart:io';
+import 'package:mysql1/mysql1.dart';
+import 'package:mess_api/config.dart';
+
+Future<void> testDbConnection() async {
+    final settings = ConnectionSettings(
+        host: DBConfig.dbHost,
+        port: DBConfig.dbPort,
+        user: DBConfig.dbUser,
+        password: DBConfig.dbPassword,
+        db: DBConfig.dbName,
+    );
+
+    final conn = await MySqlConnection.connect(settings);
+
+    final results = await conn.query(
+        'SELECT test_number FROM test_table LIMIT 1',
+    );
+
+    if (results.isEmpty) {
+        throw Exception('DB CONNECT FAIL: no data');
+    }
+
+    final value = results.first['test_number'];
+
+    if (value != 777) {
+        throw Exception('DB CONNECT FAIL: value=$value');
+    }
+
+    print('DB CONNECT OK (777)');
+
+    await conn.close();
+}
+
+void main() async {
+    await testDbConnection();
+
+    final server = await HttpServer.bind(
+        InternetAddress.anyIPv4,
+        AppConfig.port,
+    );
+
+    print('API server running on http://localhost:${AppConfig.port}');
+
+    await for (HttpRequest request in server) {
+        request.response
+            ..statusCode = HttpStatus.ok
+            ..write('ok')
+            ..close();
+    }
+}