chopper_http_utils.dart

import 'package:async/async.dart';
import 'package:chopper/chopper.dart' as chopper;
import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:http/http.dart';

abstract class RequestCopier {
  const RequestCopier._();

  factory RequestCopier({
    required BaseRequest original,
  }) = _RequestCopierImpl;

  BaseRequest copyRequest({
    int? contentLength,
    bool? followRedirects,
    Map<String, String>? headers,
    int? maxRedirects,
    bool? persistentConnection,
  });
}

class _RequestCopierImpl extends RequestCopier {
  _RequestCopierImpl({required this.original})
      : splitter = StreamSplitter(original.finalize()),
        super._();

  final BaseRequest original;
  final StreamSplitter<List<int>> splitter;

  @override
  BaseRequest copyRequest({
    Object? contentLength = freezed,
    bool? followRedirects,
    Map<String, String>? headers,
    int? maxRedirects,
    bool? persistentConnection,
  }) {
    final request = StreamedRequest(original.method, original.url)
      ..contentLength = contentLength == freezed
          ? original.contentLength
          : contentLength as int?
      ..followRedirects = followRedirects ?? original.followRedirects
      ..headers.addAll(headers ?? original.headers)
      ..maxRedirects = maxRedirects ?? original.maxRedirects
      ..persistentConnection =
          persistentConnection ?? original.persistentConnection;

    splitter.split().listen(
          request.sink.add,
          onError: request.sink.addError,
          onDone: request.sink.close,
          cancelOnError: true,
        );

    return request;
  }
}

class HttpException implements Exception {
  const HttpException({
    this.uri,
    required this.statusCode,
    required this.body,
  });

  factory HttpException.fromChopper(chopper.Response<Object?> response) {
    final body = response.bodyString;
    return HttpException(
      uri: response.base.request?.url,
      statusCode: response.statusCode,
      body: body.isEmpty ? null : body,
    );
  }

  static void ensureSuccess(chopper.Response<Object?> response) {
    if (!response.isSuccessful) {
      throw HttpException.fromChopper(response);
    }
  }

  final Uri? uri;
  final int statusCode;
  final String? body;

  @override
  String toString() {
    return 'HttpException: Error $statusCode${uri == null ? '' : ' from $uri'}'
        '${body == null ? '' : ':\n$body'}';
  }
}