fix: update docs and improve multipart support

README.md

@@ -69,24 +69,26 @@ import 'package:http_interceptor/http_interceptor.dart';
 
 In order to implement `http_interceptor` you need to implement the `InterceptorContract` and create your own interceptor. This abstract class has two methods: `interceptRequest`, which triggers before the http request is called; and `interceptResponse`, which triggers after the request is called, it has a response attached to it which the corresponding to said request. You could use this to do logging, adding headers, error handling, or many other cool stuff. It is important to note that after you proccess the request/response objects you need to return them so that `http` can continue the execute.
 
+`interceptRequest` and `interceptResponse` use `FutureOr` syntax, which makes it easier to support both synchronous and asynchronous behaviors.
+
 - Logging with interceptor:
 
 ```dart
 class LoggerInterceptor extends InterceptorContract {
   @override
-  Future<BaseRequest> interceptRequest({
+  BaseRequest interceptRequest({
     required BaseRequest request,
-  }) async {
+  }) {
     print('----- Request -----');
     print(request.toString());
     print(request.headers.toString());
     return request;
   }
 
   @override
-  Future<BaseResponse> interceptResponse({
+  BaseResponse interceptResponse({
     required BaseResponse response,
-  }) async {
+  }) {
     log('----- Response -----');
     log('Code: ${response.statusCode}');
     if (response is Response) {
@@ -102,7 +104,7 @@ class LoggerInterceptor extends InterceptorContract {
 ```dart
 class WeatherApiInterceptor implements InterceptorContract {
   @override
-  Future<BaseRequest> interceptRequest({required BaseRequest request}) async {
+  FutureOr<BaseRequest> interceptRequest({required BaseRequest request}) async {
     try {
       request.url.queryParameters['appid'] = OPEN_WEATHER_API_KEY;
       request.url.queryParameters['units'] = 'metric';
@@ -114,7 +116,10 @@ class WeatherApiInterceptor implements InterceptorContract {
   }
 
   @override
-  Future<BaseResponse> interceptResponse({required BaseResponse response}) async => response;
+  BaseResponse interceptResponse({
+  required BaseResponse response,
+  }) =>
+      response;
 }
 ```
 
@@ -123,15 +128,15 @@ class WeatherApiInterceptor implements InterceptorContract {
 ```dart
 class MultipartRequestInterceptor implements InterceptorContract {
   @override
-  Future<BaseRequest> interceptRequest({required BaseRequest request}) async {
+  FutureOr<BaseRequest> interceptRequest({required BaseRequest request}) async {
     if(request is MultipartRequest){
       request.fields['app_version'] = await PackageInfo.fromPlatform().version;
     }
     return request;
   }
 
   @override
-  Future<BaseResponse> interceptResponse({required BaseResponse response}) async {
+  FutureOr<BaseResponse> interceptResponse({required BaseResponse response}) async {
     if(response is StreamedResponse){
       response.stream.asBroadcastStream().listen((data){
         print(data);

example/lib/common.dart

@@ -4,9 +4,9 @@ import 'package:http_interceptor/http_interceptor.dart';
 
 class LoggerInterceptor extends InterceptorContract {
   @override
-  Future<BaseRequest> interceptRequest({
+  BaseRequest interceptRequest({
     required BaseRequest request,
-  }) async {
+  }) {
     log('----- Request -----');
     log(request.toString());
     log(request.headers.toString());
@@ -15,9 +15,9 @@ class LoggerInterceptor extends InterceptorContract {
   }
 
   @override
-  Future<BaseResponse> interceptResponse({
+  BaseResponse interceptResponse({
     required BaseResponse response,
-  }) async {
+  }) {
     log('----- Response -----');
     log('Code: ${response.statusCode}');
     log('Response type: ${response.runtimeType}');

example/lib/multipart_app.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:developer';
 import 'dart:io';
 import 'dart:typed_data';
@@ -171,8 +172,8 @@ class RemoveBgApiInterceptor extends InterceptorContract {
   }
 
   @override
-  Future<BaseResponse> interceptResponse({
+  BaseResponse interceptResponse({
     required BaseResponse response,
-  }) async =>
+  }) =>
       response;
 }

example/lib/weather_app.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:convert';
 import 'dart:developer';
 import 'dart:io';
@@ -267,15 +268,15 @@ class WeatherRepository {
   //   var parsedWeather;
   //   try {
   //     var response = await InterceptedHttp.build(
-  //             interceptors: [WeatherApiInterceptor()])
-  //         .get("$baseUrl/weather", params: {'id': "$id"});
+  //       interceptors: [WeatherApiInterceptor()],
+  //     ).get('$baseUrl/weather', params: {'id': '$id'});
   //     if (response.statusCode == 200) {
   //       parsedWeather = json.decode(response.body);
   //     } else {
-  //       throw Exception("Error while fetching. \n ${response.body}");
+  //       throw Exception('Error while fetching. \n ${response.body}');
   //     }
   //   } catch (e) {
-  //     log(e);
+  //     log(e.toString());
   //   }
   //   return parsedWeather;
   // }
@@ -326,8 +327,9 @@ class WeatherApiInterceptor extends InterceptorContract {
   }
 
   @override
-  Future<BaseResponse> interceptResponse(
-          {required BaseResponse response}) async =>
+  BaseResponse interceptResponse({
+    required BaseResponse response,
+  }) =>
       response;
 }
 

lib/extensions/multipart_request.dart

@@ -14,16 +14,27 @@ extension MultipartRequestCopyWith on MultipartRequest {
     bool? followRedirects,
     int? maxRedirects,
     bool? persistentConnection,
-  }) =>
-      MultipartRequest(
-        method?.asString ?? this.method,
-        url ?? this.url,
-      )
-        ..headers.addAll(headers ?? this.headers)
-        ..fields.addAll(fields ?? this.fields)
-        ..files.addAll(files ?? this.files)
-        ..followRedirects = followRedirects ?? this.followRedirects
-        ..maxRedirects = maxRedirects ?? this.maxRedirects
-        ..persistentConnection =
-            persistentConnection ?? this.persistentConnection;
+  }) {
+    var clonedRequest =
+        MultipartRequest(method?.asString ?? this.method, url ?? this.url)
+          ..headers.addAll(headers ?? this.headers)
+          ..fields.addAll(fields ?? this.fields);
+
+    for (var file in this.files) {
+      clonedRequest.files.add(MultipartFile(
+        file.field,
+        file.finalize(),
+        file.length,
+        filename: file.filename,
+        contentType: file.contentType,
+      ));
+    }
+
+    this.persistentConnection =
+        persistentConnection ?? this.persistentConnection;
+    this.followRedirects = followRedirects ?? this.followRedirects;
+    this.maxRedirects = maxRedirects ?? this.maxRedirects;
+
+    return clonedRequest;
+  }
 }

lib/extensions/streamed_request.dart

@@ -14,25 +14,27 @@ extension StreamedRequestCopyWith on StreamedRequest {
     int? maxRedirects,
     bool? persistentConnection,
   }) {
-    final req = StreamedRequest(
-      method?.asString ?? this.method,
-      url ?? this.url,
-    )
-      ..headers.addAll(headers ?? this.headers)
-      ..followRedirects = followRedirects ?? this.followRedirects
-      ..maxRedirects = maxRedirects ?? this.maxRedirects
-      ..persistentConnection =
-          persistentConnection ?? this.persistentConnection;
+    // Create a new StreamedRequest with the same method and URL
+    var clonedRequest =
+        StreamedRequest(method?.asString ?? this.method, url ?? this.url)
+          ..headers.addAll(headers ?? this.headers);
 
-    if (stream != null) {
-      stream.listen((data) {
-        req.sink.add(data);
-      });
-      finalize().listen((data) {
-        req.sink.add(data);
-      });
-    }
+    // Use a broadcast stream to allow multiple listeners
+    var broadcastStream =
+        stream?.asBroadcastStream() ?? finalize().asBroadcastStream();
 
-    return req;
+    // Pipe the broadcast stream into the cloned request's sink
+    broadcastStream.listen((data) {
+      clonedRequest.sink.add(data);
+    }, onDone: () {
+      clonedRequest.sink.close();
+    });
+
+    this.persistentConnection =
+        persistentConnection ?? this.persistentConnection;
+    this.followRedirects = followRedirects ?? this.followRedirects;
+    this.maxRedirects = maxRedirects ?? this.maxRedirects;
+
+    return clonedRequest;
   }
 }

lib/http/intercepted_client.dart

@@ -219,7 +219,13 @@ class InterceptedClient extends BaseClient {
 
     final interceptedResponse = await _interceptResponse(response);
 
-    return interceptedResponse as StreamedResponse;
+    if (interceptedResponse is StreamedResponse) {
+      return interceptedResponse;
+    }
+
+    throw ClientException(
+      'Expected `StreamedResponse`, got ${interceptedResponse.runtimeType}.',
+    );
   }
 
   Future<BaseResponse> _sendUnstreamed({

lib/models/interceptor_contract.dart

@@ -14,13 +14,13 @@ import 'package:http/http.dart';
 ///```dart
 /// class LoggingInterceptor implements InterceptorContract {
 ///  @override
-///  Future<BaseRequest> interceptRequest({required BaseRequest request}) async {
+///  FutureOr<BaseRequest> interceptRequest({required BaseRequest request}) async {
 ///    print(request.toString());
 ///    return data;
 ///  }
 ///
 ///  @override
-///  Future<BaseResponse> interceptResponse({required BaseResponse response}) async {
+///  FutureOr<BaseResponse> interceptResponse({required BaseResponse response}) async {
 ///      print(response.toString());
 ///      return data;
 ///  }