// plain dart file, requires package:shelf
import 'package:shelf/shelf.dart';
import 'package:shelf/shelf_io.dart' as io;

void main() async {
  final handler = (Request request) {
    if (request.url.path == 'missing') {
      // The backend correctly returns 404 with a specific JSON error
      return Response.notFound(
        '{"error": "Custom backend error message"}',
        headers: {'content-type': 'application/json'},
      );
    }
    return Response.ok('ok');
  };

  var server = await io.serve(handler, 'localhost', 8080);
  print('Backend listening on port ${server.port}');
}

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

void main() {
  runApp(const MaterialApp(home: ProxyTest()));
}

class ProxyTest extends StatelessWidget {
  const ProxyTest({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ElevatedButton(
          child: const Text("Fetch 404 Endpoint"),
          onPressed: () async {
            // Requesting the proxied route
            final response = await http.get(Uri.parse('/api/missing'));
            
            print('--- DEBUG INFO ---');
            print('Status Code: ${response.statusCode}');
            print('Content-Type: ${response.headers['content-type']}');
            print('Body: ${response.body}');
          },
        ),
      ),
    );
  }
}