Debug proxy as external tool

src/Components/Blazor.sln

@@ -103,6 +103,10 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Authentication.Msal", "Auth
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.Authentication.WebAssembly.Msal", "WebAssembly\Authentication.Msal\src\Microsoft.Authentication.WebAssembly.Msal.csproj", "{2F105FA7-74DA-4855-9D8E-818DEE1F8D43}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "DebugProxy", "DebugProxy", "{96DE9B14-D81F-422E-A33A-728BFB9C153A}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.AspNetCore.Components.WebAssembly.DebugProxy", "WebAssembly\DebugProxy\src\Microsoft.AspNetCore.Components.WebAssembly.DebugProxy.csproj", "{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -521,6 +525,18 @@ Global
 		{2F105FA7-74DA-4855-9D8E-818DEE1F8D43}.Release|x64.Build.0 = Release|Any CPU
 		{2F105FA7-74DA-4855-9D8E-818DEE1F8D43}.Release|x86.ActiveCfg = Release|Any CPU
 		{2F105FA7-74DA-4855-9D8E-818DEE1F8D43}.Release|x86.Build.0 = Release|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Debug|x64.Build.0 = Debug|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Debug|x86.Build.0 = Debug|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Release|x64.ActiveCfg = Release|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Release|x64.Build.0 = Release|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Release|x86.ActiveCfg = Release|Any CPU
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -573,6 +589,8 @@ Global
 		{EAF50654-98ED-44BB-A120-0436EC0CD3E0} = {CBD2BB24-3EC3-4950-ABE4-8C521D258DCD}
 		{E4D756A7-A934-4D7F-BC6E-7B95FE4098AB} = {B29FB58D-FAE5-405E-9695-BCF93582BE9A}
 		{2F105FA7-74DA-4855-9D8E-818DEE1F8D43} = {E4D756A7-A934-4D7F-BC6E-7B95FE4098AB}
+		{96DE9B14-D81F-422E-A33A-728BFB9C153A} = {B29FB58D-FAE5-405E-9695-BCF93582BE9A}
+		{8BB1A8BE-F002-40A2-9B8E-439284B21C1C} = {96DE9B14-D81F-422E-A33A-728BFB9C153A}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {27A36094-AA50-4FFD-ADE6-C055E391F741}

src/Components/WebAssembly/DebugProxy/src/DebugProxyOptions.cs

@@ -0,0 +1,10 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace Microsoft.AspNetCore.Components.WebAssembly.DebugProxy
+{
+    public class DebugProxyOptions
+    {
+        public string BrowserHost { get; set; }
+    }
+}

src/Components/WebAssembly/DebugProxy/src/Microsoft.AspNetCore.Components.WebAssembly.DebugProxy.csproj

@@ -0,0 +1,26 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
+    <OutputType>Exe</OutputType>
+    <PackageId>Microsoft.AspNetCore.Components.WebAssembly.DebugProxy</PackageId>
+    <IsShippingPackage>true</IsShippingPackage>
+    <HasReferenceAssembly>false</HasReferenceAssembly>
+    <Description>Debug proxy for use when building Blazor applications.</Description>
+    <!-- Set this to false because assemblies should not reference this assembly directly, (except for tests, of course). -->
+    <IsProjectReferenceProvider>false</IsProjectReferenceProvider>
+
+    <!-- This is so that we add the FrameworkReference to Microsoft.AspNetCore.App -->
+    <UseLatestAspNetCoreReference>true</UseLatestAspNetCoreReference>
+    <MicrosoftAspNetCoreAppVersion>3.1.0</MicrosoftAspNetCoreAppVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Reference Include="Microsoft.Extensions.CommandLineUtils.Sources" />
+
+    <!-- Dependencies of ws-proxy sources -->
+    <Reference Include="Newtonsoft.Json" />
+    <Reference Include="Mono.Cecil" />
+  </ItemGroup>
+
+</Project>

src/Components/WebAssembly/Server/src/MonoDebugProxy/ws-proxy/DevToolsProxy.cs → src/Components/WebAssembly/DebugProxy/src/MonoDebugProxy/ws-proxy/DevToolsProxy.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Linq;
 using System.Threading.Tasks;
 using Newtonsoft.Json.Linq;

src/Components/WebAssembly/DebugProxy/src/Program.cs

@@ -0,0 +1,91 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Diagnostics;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.CommandLineUtils;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace Microsoft.AspNetCore.Components.WebAssembly.DebugProxy
+{
+    public class Program
+    {
+        static int Main(string[] args)
+        {
+            var app = new CommandLineApplication(throwOnUnexpectedArg: false)
+            {
+                Name = "webassembly-debugproxy"
+            };
+            app.HelpOption("-?|-h|--help");
+
+            var browserHostOption = new CommandOption("-b|--browser-host", CommandOptionType.SingleValue)
+            {
+                Description = "Host on which the browser is listening for debug connections. Example: http://localhost:9300"
+            };
+
+            var ownerPidOption = new CommandOption("-op|--owner-pid", CommandOptionType.SingleValue)
+            {
+                Description = "ID of the owner process. The debug proxy will shut down if this process exits."
+            };
+
+            app.Options.Add(browserHostOption);
+            app.Options.Add(ownerPidOption);
+
+            app.OnExecute(() =>
+            {
+                var host = Host.CreateDefaultBuilder(args)
+                    .ConfigureAppConfiguration((hostingContext, config) =>
+                    {
+                        config.AddCommandLine(args);
+                    })
+                    .ConfigureWebHostDefaults(webBuilder =>
+                    {
+                        webBuilder.UseStartup<Startup>();
+
+                        // By default we bind to a dyamic port
+                        // This can be overridden using an option like "--urls http://localhost:9500"
+                        webBuilder.UseUrls("http://127.0.0.1:0");
+                    })
+                    .ConfigureServices(serviceCollection =>
+                    {
+                        serviceCollection.AddSingleton(new DebugProxyOptions
+                        {
+                            BrowserHost = browserHostOption.HasValue()
+                                ? browserHostOption.Value()
+                                : "http://127.0.0.1:9222",
+                        });
+                    })
+                    .Build();
+
+                if (ownerPidOption.HasValue())
+                {
+                    var ownerProcess = Process.GetProcessById(int.Parse(ownerPidOption.Value()));
+                    ownerProcess.EnableRaisingEvents = true;
+                    ownerProcess.Exited += async (sender, eventArgs) =>
+                    {
+                        Console.WriteLine("Exiting because parent process has exited");
+                        await host.StopAsync();
+                    };
+                }
+
+                host.Run();
+
+                return 0;
+            });
+
+            try
+            {
+                return app.Execute(args);
+            }
+            catch (CommandParsingException cex)
+            {
+                app.Error.WriteLine(cex.Message);
+                app.ShowHelp();
+                return 1;
+            }
+        }
+    }
+}

src/Components/WebAssembly/DebugProxy/src/Startup.cs

@@ -0,0 +1,45 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Net;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using WebAssembly.Net.Debugging;
+
+namespace Microsoft.AspNetCore.Components.WebAssembly.DebugProxy
+{
+    public class Startup
+    {
+        public void Configure(IApplicationBuilder app, DebugProxyOptions debugProxyOptions)
+        {
+            app.UseDeveloperExceptionPage();
+            app.UseWebSockets();
+            app.UseRouting();
+
+            app.UseEndpoints(endpoints =>
+            {
+                // At the homepage, we check whether we can uniquely identify the target tab
+                //  - If yes, we redirect directly to the debug tools, proxying to that tab
+                //  - If no, we present a list of available tabs for the user to pick from
+                endpoints.MapGet("/", new TargetPickerUi(debugProxyOptions).Display);
+
+                // At this URL, we wire up the actual WebAssembly proxy
+                endpoints.MapGet("/ws-proxy", async (context) =>
+                {
+                    if (!context.WebSockets.IsWebSocketRequest)
+                    {
+                        context.Response.StatusCode = (int)HttpStatusCode.BadRequest;
+                        return;
+                    }
+
+                    var loggerFactory = context.RequestServices.GetRequiredService<ILoggerFactory>();
+                    var browserUri = new Uri(context.Request.Query["browser"]);
+                    var ideSocket = await context.WebSockets.AcceptWebSocketAsync();
+                    await new MonoProxy(loggerFactory).Run(browserUri, ideSocket);
+                });
+            });
+        }
+    }
+}