♻️ Move cancelable operation into the core

dio/lib/src/adapters/io_adapter.dart

@@ -2,8 +2,6 @@ import 'dart:async';
 import 'dart:io';
 import 'dart:typed_data';
 
-import 'package:async/async.dart';
-
 import '../adapter.dart';
 import '../dio_exception.dart';
 import '../options.dart';
@@ -70,14 +68,7 @@ class IOHttpClientAdapter implements HttpClientAdapter {
         "Can't establish connection after the adapter was closed.",
       );
     }
-    final operation = CancelableOperation.fromFuture(
-      _fetch(options, requestStream, cancelFuture),
-    );
-    final wr = WeakReference<CancelableOperation<ResponseBody>>(operation);
-    cancelFuture?.whenComplete(() {
-      wr.target?.cancel();
-    });
-    return operation.value;
+    return _fetch(options, requestStream, cancelFuture);
   }
 
   Future<ResponseBody> _fetch(

dio/lib/src/dio_mixin.dart

@@ -4,6 +4,7 @@ import 'dart:convert';
 import 'dart:math' as math;
 import 'dart:typed_data';
 
+import 'package:async/async.dart';
 import 'package:meta/meta.dart';
 
 import 'adapter.dart';
@@ -524,11 +525,18 @@ abstract class DioMixin implements Dio {
     final cancelToken = reqOpt.cancelToken;
     try {
       final stream = await _transformData(reqOpt);
-      final responseBody = await httpClientAdapter.fetch(
-        reqOpt,
-        stream,
-        cancelToken?.whenCancel,
+      final operation = CancelableOperation.fromFuture(
+        httpClientAdapter.fetch(
+          reqOpt,
+          stream,
+          cancelToken?.whenCancel,
+        ),
       );
+      final operationWeakReference = WeakReference(operation);
+      cancelToken?.whenCancel.whenComplete(() {
+        operationWeakReference.target?.cancel();
+      });
+      final responseBody = await operation.value;
       final headers = Headers.fromMap(
         responseBody.headers,
         preserveHeaderCase: reqOpt.preserveHeaderCase,

dio/pubspec.yaml

@@ -20,7 +20,7 @@ environment:
   sdk: '>=2.18.0 <4.0.0'
 
 dependencies:
-  async: ^2.11.0
+  async: ^2.8.2
   http_parser: ^4.0.0
   meta: ^1.5.0
   path: ^1.8.0

plugins/http2_adapter/lib/src/http2_adapter.dart

@@ -3,7 +3,6 @@ import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
 
-import 'package:async/async.dart';
 import 'package:dio/dio.dart';
 import 'package:dio/io.dart';
 import 'package:http2/http2.dart';
@@ -49,14 +48,7 @@ class Http2Adapter implements HttpClientAdapter {
   ) {
     // Recursive fetching.
     final redirects = <RedirectRecord>[];
-    final operation = CancelableOperation.fromFuture(
-      _fetch(options, requestStream, cancelFuture, redirects),
-    );
-    final wr = WeakReference<CancelableOperation<ResponseBody>>(operation);
-    cancelFuture?.whenComplete(() {
-      wr.target?.cancel();
-    });
-    return operation.value;
+    return _fetch(options, requestStream, cancelFuture, redirects);
   }
 
   Future<ResponseBody> _fetch(

plugins/http2_adapter/pubspec.yaml

@@ -15,7 +15,6 @@ environment:
   sdk: ">=3.0.0 <4.0.0"
 
 dependencies:
-  async: ^2.11.0
   dio: ^5.2.0
   http2: ^2.1.0
   meta: ^1.9.1