[ DWDS ] Write to WebkitDebugger.onClose if the debugger connection closes and the attempts to reconnect fail (#2785)

The Flutter tool expects DebugConnection.onDone to complete if the user exits the browser and the debugger connection closes.

After receiving notification of a closed connection, WebkitDebugger tries to reconnect to the debugger.  If these attempts fail, WebkitDebugger will now write to its onClose stream so that DebugConnection will know to signal onDone.

See flutter/flutter#182897

Author: jason-simmons

dwds/CHANGELOG.md

@@ -12,6 +12,7 @@
 - Fix serialization of `HotRestartRequest` in `AppConnection`.
 - Split integration tests across DDC module systems.
 - Split additional tests across DDC module systems.
+- Fix issue where `DebugConnection` did not complete `onDone` if `WebkitDebugger` fails to reconnect to the debugger after the connection closes.
 
 ## 27.0.0
 - Remove `package:built_value`, `package:built_value_generator`, and `package:built_collection` dependencies.

dwds/lib/src/debugging/webkit_debugger.dart

@@ -69,13 +69,7 @@ class WebkitDebugger implements RemoteDebugger {
       await sub.cancel();
       if (_closed != null) {
         // The connection closing is expected.
-        _onClosedController.add(connection);
-        await Future.wait([
-          for (final controller in _controllers) controller.close(),
-          for (final MapEntry(value: (:controller, transformer: _))
-              in _eventStreams.entries)
-            controller.close(),
-        ]);
+        await _shutdown(connection);
         return;
       }
       var retry = false;
@@ -94,7 +88,11 @@ class WebkitDebugger implements RemoteDebugger {
           retryCount++;
         }
       } while (retry && retryCount <= maxAttempts);
-      _initialize();
+      if (retryCount > maxAttempts) {
+        await _shutdown(connection);
+      } else {
+        _initialize();
+      }
     });
 
     final runtime = _wipDebugger.connection.runtime;
@@ -125,6 +123,16 @@ class WebkitDebugger implements RemoteDebugger {
       ]);
   }
 
+  Future<void> _shutdown(WipConnection connection) async {
+    _onClosedController.add(connection);
+    await Future.wait([
+      for (final controller in _controllers) controller.close(),
+      for (final MapEntry(value: (:controller, transformer: _))
+          in _eventStreams.entries)
+        controller.close(),
+    ]);
+  }
+
   @override
   Stream<ConsoleAPIEvent> get onConsoleAPICalled =>
       _onConsoleAPICalledController.stream;