water-management-system/test/water_data_model_test.dart

import 'package:flutter_test/flutter_test.dart';
import 'package:water_management_system/models/water_data_model.dart';

void main() {
  group('WaterDataModel', () {
    test('should create model with all fields', () {
      final model = WaterDataModel(
        deviceId: 'D001', deviceName: 'Test Station', area: 'East',
        pressure: 0.35, flowRate: 120.5, temperature: 22.0,
        status: 'normal', updateTime: DateTime(2026, 6, 17, 16, 0),
        batteryLevel: 95.0, location: '116.3,39.9',
      );
      expect(model.deviceId, 'D001');
      expect(model.pressure, 0.35);
      expect(model.status, 'normal');
    });

    test('fromJson should parse JSON correctly', () {
      final model = WaterDataModel.fromJson({
        'device_id': 'D002', 'device_name': 'Station B', 'area': 'West',
        'pressure': 0.42, 'flow_rate': 150.0, 'status': 'warning',
        'update_time': '2026-06-17T15:30:00', 'battery_level': 78.0,
      });
      expect(model.deviceId, 'D002');
      expect(model.pressure, 0.42);
      expect(model.status, 'warning');
    });

    test('fromJson should handle missing fields', () {
      final model = WaterDataModel.fromJson({});
      expect(model.deviceId, '');
      expect(model.pressure, 0.0);
      expect(model.status, 'unknown');
    });

    test('toJson should serialize all fields', () {
      final model = WaterDataModel(
        deviceId: 'D003', deviceName: 'C', area: 'S',
        pressure: 0.28, flowRate: 85.0, temperature: 21.0,
        status: 'error', updateTime: DateTime(2026, 6, 17),
        batteryLevel: 45.0, location: '116.2',
      );
      final json = model.toJson();
      expect(json['device_id'], 'D003');
      expect(json['status'], 'error');
    });

    test('needsWarning should be true for warning/error', () {
      expect(WaterDataModel.fromJson({'status': 'warning'}).needsWarning, true);
      expect(WaterDataModel.fromJson({'status': 'error'}).needsWarning, true);
      expect(WaterDataModel.fromJson({'status': 'normal'}).needsWarning, false);
    });

    test('copyWith should update specified fields', () {
      final orig = WaterDataModel.fromJson({'device_id': '1', 'pressure': 0.35});
      final updated = orig.copyWith(pressure: 0.40);
      expect(updated.pressure, 0.40);
      expect(updated.deviceId, '1');
    });
  });
}