[ Service ] Fix dart:developer service extensions, add getSupportedProtocols

Brings package:vm_service test suite pass rate up to ~93%

Change-Id: I108a24e1acf37eb69c9de25a2f7334eb4c56dbe6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/487600
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>

pkg/dart_runtime_service/lib/dart_runtime_service.dart

@@ -6,6 +6,11 @@ export 'src/clients.dart';
 export 'src/dart_runtime_service.dart';
 export 'src/dart_runtime_service_backend.dart';
 export 'src/dart_runtime_service_options.dart';
+export 'src/dart_runtime_service_rpcs.dart'
+    show
+        RpcHandlerWithNoParameters,
+        RpcHandlerWithParameters,
+        ServiceRpcHandler;
 export 'src/event_streams.dart';
 export 'src/exceptions.dart';
 export 'src/expression_evaluator.dart';

pkg/dart_runtime_service/lib/src/clients.dart

@@ -76,10 +76,11 @@ base class Client {
 
   @mustCallSuper
   void registerRpcHandlers() {
-    _internalRpcs.registerRpcsWithPeer(_clientPeer);
-    backend.registerRpcs(_clientPeer);
-    _internalRpcs.registerServiceExtensionForwarder(_clientPeer);
-    backend.registerFallbacks(_clientPeer);
+    _internalRpcs
+      ..addBackendRpcs(backend: backend)
+      ..registerRpcsWithPeer(_clientPeer)
+      ..registerServiceExtensionForwarder(_clientPeer)
+      ..registerBackendFallbacks(_clientPeer);
   }
 
   /// Attempts to register a [service] to be provided by this client.

pkg/dart_runtime_service/lib/src/dart_runtime_service_backend.dart

@@ -2,10 +2,12 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc;
+import 'dart:collection';
+
 import 'package:meta/meta.dart';
 
 import 'dart_runtime_service.dart';
+import 'dart_runtime_service_rpcs.dart';
 import 'event_streams.dart';
 import 'expression_evaluator.dart';
 import 'isolate_manager.dart';
@@ -72,14 +74,14 @@ abstract class DartRuntimeServiceBackend<IM extends IsolateManager> {
   /// more clients listening to [streamId].
   void onStreamCancel({required String streamId}) {}
 
-  /// Invoked by the [DartRuntimeService] to register handlers for the RPCs
-  /// provided by the backend.
-  void registerRpcs(json_rpc.Peer clientPeer);
+  /// RPCs to be registered with the [DartRuntimeService].
+  UnmodifiableListView<ServiceRpcHandler> get rpcs =>
+      UnmodifiableListView(const []);
 
-  /// Invoked by the [DartRuntimeService] to register fallback handlers
-  /// provided by the backend.
+  /// Fallbacks to be registered with the [DartRuntimeService].
   ///
   /// Backend fallbacks are executed after incoming RPC requests fail to match
   /// any registered RPCs or service extensions provided by other clients.
-  void registerFallbacks(json_rpc.Peer clientPeer);
+  UnmodifiableListView<RpcHandlerWithParameters> get fallbacks =>
+      UnmodifiableListView(const []);
 }

pkg/dart_runtime_service/lib/src/dart_runtime_service_rpcs.dart

@@ -11,6 +11,7 @@ import 'package:vm_service/vm_service.dart';
 
 import 'clients.dart';
 import 'dart_runtime_service.dart';
+import 'dart_runtime_service_backend.dart';
 import 'event_streams.dart';
 import 'expression_evaluator.dart';
 import 'rpc_exceptions.dart';
@@ -20,6 +21,8 @@ typedef RpcHandlerWithNoParameters = FutureOr<RpcResponse> Function();
 typedef RpcHandlerWithParameters =
     FutureOr<RpcResponse> Function(json_rpc.Parameters);
 
+typedef ServiceRpcHandler = (String, Function?);
+
 /// Manages requests made to platform-agnostic RPCs provided by
 /// [DartRuntimeService] by a single [Client].
 final class DartRuntimeServiceRpcs {
@@ -49,7 +52,7 @@ final class DartRuntimeServiceRpcs {
   // Parameters for streamListen
   static const _kStreamId = 'streamId';
 
-  late final _commonRpcs = <(String, Function?)>[
+  late final _commonRpcs = <ServiceRpcHandler>[
     ('getClientName', getClientName),
     ('registerService', registerService),
     ('setClientName', setClientName),
@@ -59,9 +62,22 @@ final class DartRuntimeServiceRpcs {
     ('evaluateInFrame', expressionEvaluator?.evaluateInFrame),
   ];
 
-  /// Registers the set of platform-agnostic RPCs for use by [client].
+  final _backendRpcs = <ServiceRpcHandler>[];
+  final _backendFallbacks = <RpcHandlerWithParameters>[];
+
+  void addBackendRpcs({required DartRuntimeServiceBackend backend}) {
+    _backendRpcs.addAll(backend.rpcs);
+    _backendFallbacks.addAll(backend.fallbacks);
+  }
+
+  void addBackendFallbacks({
+    required List<RpcHandlerWithParameters> fallbacks,
+  }) => _backendFallbacks.addAll(fallbacks);
+
+  /// Registers the set of platform-agnostic and backend RPCs for use by
+  /// [client].
   void registerRpcsWithPeer(json_rpc.Peer clientPeer) {
-    for (final (method, callback) in _commonRpcs) {
+    for (final (method, callback) in [..._commonRpcs, ..._backendRpcs]) {
       if (callback == null) continue;
       if (callback is! RpcHandlerWithNoParameters &&
           callback is! RpcHandlerWithParameters) {
@@ -92,6 +108,12 @@ final class DartRuntimeServiceRpcs {
     clientPeer.registerFallback(serviceExtensionForwarderFallback);
   }
 
+  void registerBackendFallbacks(json_rpc.Peer clientPeer) {
+    for (final fallback in _backendFallbacks) {
+      clientPeer.registerFallback(fallback);
+    }
+  }
+
   /// Attempts to [parse] [parameters] into an instance of [T].
   ///
   /// If [parameters] can't be parsed, a [json_rpc.RpcException] is thrown

pkg/dart_runtime_service/test/utils/mocks.dart

@@ -2,8 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:collection';
+
 import 'package:dart_runtime_service/dart_runtime_service.dart';
-import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc;
 import 'package:test/fake.dart';
 
 /// Fake implementation of [DartRuntimeServiceBackend] that throws when
@@ -32,10 +33,12 @@ base class FakeDartRuntimeServiceBackend extends Fake
   }) async {}
 
   @override
-  void registerRpcs(json_rpc.Peer clientPeer) {}
+  UnmodifiableListView<ServiceRpcHandler> get rpcs =>
+      UnmodifiableListView(const []);
 
   @override
-  void registerFallbacks(json_rpc.Peer clientPeer) {}
+  UnmodifiableListView<RpcHandlerWithParameters> get fallbacks =>
+      UnmodifiableListView(const []);
 
   @override
   DartRuntimeService get frontend => throw UnimplementedError();

pkg/dart_runtime_service_vm/lib/dart_runtime_service_vm.dart

@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
 import 'dart:isolate';
@@ -13,6 +14,7 @@ import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc;
 import 'package:logging/logging.dart';
 import 'package:stream_channel/stream_channel.dart';
 
+import 'src/dart_runtime_service_vm_rpcs.dart';
 import 'src/native_bindings.dart';
 import 'src/vm_expression_evaluator.dart';
 import 'src/vm_isolate_manager.dart';
@@ -73,6 +75,20 @@ class DartRuntimeServiceVMBackend
   @override
   late final VmExpressionEvaluator expressionEvaluator;
 
+  final _vmServiceRpcs = DartRuntimeServiceVmRpcs();
+
+  @override
+  UnmodifiableListView<ServiceRpcHandler> get rpcs =>
+      UnmodifiableListView(_vmServiceRpcs.rpcs);
+
+  @override
+  UnmodifiableListView<RpcHandlerWithParameters>
+  get fallbacks => UnmodifiableListView([
+    // If the registered Dart RPC handlers can't handle a request, forward it
+    // it to the native VM service implementation for processing.
+    sendToRuntime,
+  ]);
+
   @override
   Future<void> initialize() async {
     _logger.info('Initializing...');
@@ -148,18 +164,6 @@ class DartRuntimeServiceVMBackend
     _nativeBindings.streamCancel(streamId: streamId);
   }
 
-  @override
-  void registerRpcs(json_rpc.Peer clientPeer) {
-    // The VM service handles its service requests in service.cc.
-  }
-
-  @override
-  void registerFallbacks(json_rpc.Peer clientPeer) {
-    // If the registered Dart RPC handlers can't handle a request, forward it
-    // it to the native VM service implementation for processing.
-    clientPeer.registerFallback(sendToRuntime);
-  }
-
   /// Sends service requests to the Dart VM runtime for processing.
   Future<RpcResponse> sendToRuntime(json_rpc.Parameters request) async {
     final method = request.method;

pkg/dart_runtime_service_vm/lib/src/dart_runtime_service_vm_rpcs.dart

@@ -0,0 +1,46 @@
+// Copyright (c) 2026, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:collection';
+
+import 'package:dart_runtime_service/dart_runtime_service.dart';
+import 'package:logging/logging.dart';
+import 'package:vm_service/vm_service.dart';
+
+import 'native_bindings.dart';
+
+/// Implementations of RPCs specific to the VM service that are not handled
+/// in runtime/vm/service.cc.
+final class DartRuntimeServiceVmRpcs {
+  final _logger = Logger('$DartRuntimeServiceVmRpcs');
+  final _nativeBindings = NativeBindings();
+
+  late final rpcs = UnmodifiableListView<ServiceRpcHandler>([
+    ('getSupportedProtocols', getSupportedProtocols),
+  ]);
+
+  /// Returns the list of protocols implemented by the service.
+  ///
+  /// VM service middleware like DDS should intercept this RPC and add their
+  /// own information to the response.
+  Future<RpcResponse> getSupportedProtocols() async {
+    final version = Version.parse(
+      await _nativeBindings.sendToVM(method: 'getVersion', params: const {}),
+    );
+    if (version == null) {
+      _logger.warning('Unable to retrieve version for getSupportedProtocols.');
+      RpcException.internalError.throwException();
+    }
+
+    return ProtocolList(
+      protocols: [
+        Protocol(
+          protocolName: 'VM Service',
+          major: version.major,
+          minor: version.minor,
+        ),
+      ],
+    ).toJson();
+  }
+}

pkg/dart_runtime_service_vm/lib/src/native_bindings.dart

@@ -133,10 +133,16 @@ class NativeBindings {
     const kData = 'data';
 
     final Object? converted;
-    if (value case [final Uint8List utf8String]) {
+    if (value case final String string) {
+      converted = json.decode(string);
+    } else if (value case [final Uint8List utf8String]) {
       converted = jsonUtf8Decoder.decode(utf8String);
     } else {
-      RpcException.internalError.throwException();
+      RpcException.internalError.throwException(
+        data: {
+          'details': 'Unknown response type (${value.runtimeType}: $value)',
+        },
+      );
     }
     if (converted case {kResult: final Map<String, Object?> result}) {
       return result;