TL;DR

final isProd = bool.fromEnvironment('dart.vm.product');

config文件示例 (config.dart)

class _Config {
  final isProd = bool.fromEnvironment('dart.vm.product');

  String get appName => isProd ? 'App' : 'App (Debug)';

  String get apiBaseUrl => isProd
      ? 'https://example.com/v1'
      : 'https://dev.example.com/v1';
}

final config = _Config();