[flutter_tool] Timeout the Azure bot detector http request (#53217)

packages/flutter_tools/lib/src/base/bot_detector.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
+
 import 'package:meta/meta.dart';
 import 'package:platform/platform.dart';
 
@@ -95,12 +97,14 @@ class AzureDetector {
     if (_isRunningOnAzure != null) {
       return _isRunningOnAzure;
     }
+    const Duration connectionTimeout = Duration(milliseconds: 250);
+    const Duration requestTimeout = Duration(seconds: 1);
     final HttpClient client = _httpClientFactory()
-      ..connectionTimeout = const Duration(milliseconds: 250);
+      ..connectionTimeout = connectionTimeout;
     try {
       final HttpClientRequest request = await client.getUrl(
         Uri.parse(_serviceUrl),
-      );
+      ).timeout(requestTimeout);
       request.headers.add('Metadata', true);
       await request.close();
     } on SocketException {
@@ -111,6 +115,10 @@ class AzureDetector {
       // If the connection gets set up, but encounters an error condition, it
       // still means we're on Azure.
       return _isRunningOnAzure = true;
+    } on TimeoutException {
+      // The HttpClient connected to a host, but it did not respond in a timely
+      // fashion. Assume we are not on a bot.
+      return _isRunningOnAzure = false;
     }
     // We got a response. We're running on Azure.
     return _isRunningOnAzure = true;

packages/flutter_tools/test/general.shard/base/bot_detector_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
+
 import 'package:file/memory.dart';
 import 'package:flutter_tools/src/base/bot_detector.dart';
 import 'package:flutter_tools/src/base/io.dart';
@@ -9,6 +11,7 @@ import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/persistent_tool_state.dart';
 import 'package:mockito/mockito.dart';
 import 'package:platform/platform.dart';
+import 'package:quiver/testing/async.dart';
 
 import '../../src/common.dart';
 import '../../src/mocks.dart';
@@ -132,6 +135,19 @@ void main() {
       expect(await azureDetector.isRunningOnAzure, isFalse);
     });
 
+    testWithoutContext('isRunningOnAzure returns false when the http request times out', () {
+      FakeAsync().run((FakeAsync time) async {
+        when(mockHttpClient.getUrl(any)).thenAnswer((_) {
+          final Completer<HttpClientRequest> completer = Completer<HttpClientRequest>();
+          return completer.future;  // Never completed to test timeout behavior.
+        });
+        final Future<bool> onBot = azureDetector.isRunningOnAzure;
+        time.elapse(const Duration(seconds: 2));
+
+        expect(await onBot, isFalse);
+      });
+    });
+
     testWithoutContext('isRunningOnAzure returns true when azure metadata is reachable', () async {
       when(mockHttpClient.getUrl(any)).thenAnswer((_) {
         return Future<HttpClientRequest>.value(mockHttpClientRequest);