⚡️ Improve multiple timeout tests (#2142)

- Further try #2140, using `drip` to control the overall response
duration.
- Make cancellation calls only after the response stream has been
obtained to keep the call sequence.
- Using the non-routable URL (10.0.0.0) to mock connection timeouts.

### New Pull Request Checklist

- [x] I have read the
[Documentation](https://pub.dev/documentation/dio/latest/)
- [x] I have searched for a similar pull request in the
[project](https://github.com/cfug/dio/pulls) and found none
- [x] I have updated this branch with the latest `main` branch to avoid
conflicts (via merge from master or rebase)
- [x] I have added the required tests to prove the fix/feature I'm
adding
- [ ] I have updated the documentation (if necessary)
- [x] I have run the tests without failures
- [ ] I have updated the `CHANGELOG.md` in the corresponding package

dio/test/stacktrace_test.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 
 import 'package:dio/dio.dart';
 import 'package:dio/io.dart';
+import 'package:dio_test/util.dart';
 import 'package:mockito/mockito.dart';
 import 'package:test/test.dart';
 
@@ -60,8 +61,8 @@ void main() async {
         await HttpOverrides.runWithHttpOverrides(() async {
           final timeout = Duration(milliseconds: 10);
           final dio = Dio()
-            ..options.connectTimeout = timeout
-            ..options.baseUrl = 'https://does.not.exist';
+            ..options.baseUrl = nonRoutableUrl
+            ..options.connectTimeout = timeout;
 
           when(httpClientMock.openUrl('GET', any)).thenAnswer(
             (_) async {

dio/test/timeout_test.dart

@@ -2,6 +2,7 @@ import 'dart:io';
 
 import 'package:dio/dio.dart';
 import 'package:dio/io.dart';
+import 'package:dio_test/util.dart';
 import 'package:test/test.dart';
 
 void main() {
@@ -17,7 +18,7 @@ void main() {
       test('update between calls', () async {
         final client = HttpClient();
         final dio = Dio()
-          ..options.baseUrl = 'https://httpbun.com'
+          ..options.baseUrl = nonRoutableUrl
           ..httpClientAdapter = IOHttpClientAdapter(
             createHttpClient: () => client,
           );

dio_test/lib/src/test/download_stream_tests.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'dart:io';
 
 import 'package:dio/dio.dart';
@@ -49,16 +50,24 @@ void downloadStreamTests(
     test('cancels request', () async {
       final cancelToken = CancelToken();
 
-      Future.delayed(const Duration(milliseconds: 10), () {
+      final res = await dio.get<ResponseBody>(
+        '/drip',
+        queryParameters: {'duration': '5', 'delay': '0'},
+        options: Options(responseType: ResponseType.stream),
+        cancelToken: cancelToken,
+      );
+
+      Future.delayed(const Duration(seconds: 2), () {
         cancelToken.cancel();
       });
 
+      final completer = Completer();
+      res.data!.stream.listen((event) {}, onError: (e, s) {
+        completer.completeError(e, s);
+      });
+
       await expectLater(
-        dio.get(
-          '/bytes/10000',
-          options: Options(responseType: ResponseType.stream),
-          cancelToken: cancelToken,
-        ),
+        completer.future,
         throwsDioException(
           DioExceptionType.cancel,
           stackTraceContains: 'test/download_stream_tests.dart',
@@ -76,8 +85,9 @@ void downloadStreamTests(
 
       await expectLater(
         dio.download(
-          '/bytes/5000',
+          '/drip',
           path,
+          queryParameters: {'duration': '5', 'delay': '0'},
           cancelToken: cancelToken,
         ),
         throwsDioException(

dio_test/lib/src/test/timeout_tests.dart

@@ -4,6 +4,8 @@ import 'package:dio/dio.dart';
 import 'package:dio_test/src/matcher.dart';
 import 'package:test/test.dart';
 
+import '../utils.dart';
+
 void timeoutTests(
   Dio Function() create,
 ) {
@@ -15,10 +17,10 @@ void timeoutTests(
 
   group('Timeout exception of', () {
     group('connectTimeout', () {
-      test('with response', () async {
+      test('throws', () async {
         dio.options.connectTimeout = Duration(milliseconds: 3);
         await expectLater(
-          dio.get('/'),
+          dio.get(nonRoutableUrl),
           throwsDioException(
             DioExceptionType.connectionTimeout,
             messageContains: dio.options.connectTimeout.toString(),
@@ -98,7 +100,7 @@ void timeoutTests(
     );
     dio.options.connectTimeout = Duration(milliseconds: 10);
     await expectLater(
-      dio.get('/drip-lines?delay=1'),
+      dio.get(nonRoutableUrl),
       throwsDioException(
         DioExceptionType.connectionTimeout,
         messageContains: '0:00:00.010000',

dio_test/lib/src/utils.dart

@@ -1,3 +1,5 @@
 const kIsWeb = bool.hasEnvironment('dart.library.js_util')
     ? bool.fromEnvironment('dart.library.js_util')
     : identical(0, 0.0);
+
+const nonRoutableUrl = 'http://10.0.0.0';