Allow for setting custom DDS port

Related to flutter/flutter#159157

Author: bkonyi

dwds/lib/dart_web_debug_service.dart

@@ -128,6 +128,7 @@ class Dwds {
       debugSettings.expressionCompiler,
       injected,
       debugSettings.spawnDds,
+      debugSettings.ddsPort,
       debugSettings.launchDevToolsInNewWindow,
     );
 

dwds/lib/src/config/tool_configuration.dart

@@ -61,6 +61,7 @@ class DebugSettings {
   final bool useSseForDebugBackend;
   final bool useSseForInjectedClient;
   final bool spawnDds;
+  final int? ddsPort;
   final bool enableDevToolsLaunch;
   final bool launchDevToolsInNewWindow;
   final bool emitDebugEvents;
@@ -75,6 +76,7 @@ class DebugSettings {
     this.useSseForDebugBackend = true,
     this.useSseForInjectedClient = true,
     this.spawnDds = true,
+    this.ddsPort,
     this.enableDevToolsLaunch = true,
     this.launchDevToolsInNewWindow = true,
     this.emitDebugEvents = true,

dwds/lib/src/handlers/dev_handler.dart

@@ -66,6 +66,7 @@ class DevHandler {
   final bool _useSseForDebugProxy;
   final bool _useSseForInjectedClient;
   final bool _spawnDds;
+  final int? _ddsPort;
   final bool _launchDevToolsInNewWindow;
   final ExpressionCompiler? _expressionCompiler;
   final DwdsInjector _injected;
@@ -90,6 +91,7 @@ class DevHandler {
     this._expressionCompiler,
     this._injected,
     this._spawnDds,
+    this._ddsPort,
     this._launchDevToolsInNewWindow,
   ) {
     _subs.add(buildResults.listen(_emitBuildResults));
@@ -215,6 +217,7 @@ class DevHandler {
       useSse: false,
       expressionCompiler: _expressionCompiler,
       spawnDds: _spawnDds,
+      ddsPort: _ddsPort,
     );
   }
 
@@ -645,6 +648,7 @@ class DevHandler {
         useSse: _useSseForDebugProxy,
         expressionCompiler: _expressionCompiler,
         spawnDds: _spawnDds,
+        ddsPort: _ddsPort,
       );
       appServices = await _createAppDebugServices(
         debugService,

dwds/lib/src/services/debug_service.dart

@@ -137,6 +137,7 @@ class DebugService {
   final HttpServer _server;
   final bool _useSse;
   final bool _spawnDds;
+  final int? _ddsPort;
   final UrlEncoder? _urlEncoder;
   DartDevelopmentServiceLauncher? _dds;
 
@@ -154,6 +155,7 @@ class DebugService {
     this._server,
     this._useSse,
     this._spawnDds,
+    this._ddsPort,
     this._urlEncoder,
   );
 
@@ -175,7 +177,7 @@ class DebugService {
       serviceUri: Uri(
         scheme: 'http',
         host: hostname,
-        port: 0,
+        port: _ddsPort ?? 0,
       ),
     );
     return _dds!;
@@ -231,6 +233,7 @@ class DebugService {
     void Function(Map<String, Object>)? onRequest,
     void Function(Map<String, Object?>)? onResponse,
     bool spawnDds = true,
+    int? ddsPort,
     bool useSse = false,
     ExpressionCompiler? expressionCompiler,
   }) async {
@@ -299,6 +302,7 @@ class DebugService {
       server,
       useSse,
       spawnDds,
+      ddsPort,
       urlEncoder,
     );
   }

dwds/test/dds_port_test.dart

@@ -0,0 +1,43 @@
+// Copyright (c) 2019, 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.
+
+@TestOn('vm')
+@Timeout(Duration(minutes: 2))
+library;
+
+import 'dart:io';
+
+import 'package:test/test.dart';
+import 'package:test_common/test_sdk_configuration.dart';
+
+import 'fixtures/context.dart';
+import 'fixtures/project.dart';
+import 'fixtures/utilities.dart';
+
+void main() {
+  late final TestSdkConfigurationProvider provider;
+
+  setUp(() {
+    provider = TestSdkConfigurationProvider();
+  });
+
+  tearDown(() {
+    provider.dispose();
+  });
+
+  test('DWDS starts DDS with a specified port', () async {
+    final context = TestContext(TestProject.test, provider);
+
+    final server = await HttpServer.bind(InternetAddress.loopbackIPv4, 0);
+    final expectedPort = server.port;
+    await server.close();
+
+    await context.setUp(
+      debugSettings: TestDebugSettings.noDevTools().copyWith(
+        ddsPort: expectedPort,
+      ),
+    );
+    expect(Uri.parse(context.debugConnection.ddsUri!).port, expectedPort);
+  });
+}

dwds/test/fixtures/utilities.dart

@@ -125,6 +125,7 @@ class TestDebugSettings extends DebugSettings {
     required super.useSseForDebugProxy,
     required super.useSseForInjectedClient,
     required super.spawnDds,
+    required super.ddsPort,
     required super.enableDevToolsLaunch,
     required super.launchDevToolsInNewWindow,
     required super.emitDebugEvents,
@@ -138,6 +139,7 @@ class TestDebugSettings extends DebugSettings {
     bool? enableDebugExtension,
     bool? useSse,
     bool? spawnDds,
+    int? ddsPort,
     bool? enableDevToolsLaunch,
     bool? launchDevToolsInNewWindow,
     bool? emitDebugEvents,
@@ -152,6 +154,7 @@ class TestDebugSettings extends DebugSettings {
       useSseForDebugBackend: useSse ?? useSseForDebugBackend,
       useSseForInjectedClient: useSse ?? useSseForInjectedClient,
       spawnDds: spawnDds ?? this.spawnDds,
+      ddsPort: ddsPort ?? this.ddsPort,
       enableDevToolsLaunch: enableDevToolsLaunch ?? this.enableDevToolsLaunch,
       launchDevToolsInNewWindow:
           launchDevToolsInNewWindow ?? this.launchDevToolsInNewWindow,