Ability to run E2E tests on WebAssembly multithreaded runtime

src/Components/test/E2ETest/Infrastructure/ServerFixtures/BlazorWasmTestAppFixture.cs

@@ -9,6 +9,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
+using TestServer;
 using DevHostServerProgram = Microsoft.AspNetCore.Components.WebAssembly.DevServer.Server.Program;
 
 namespace Microsoft.AspNetCore.Components.E2ETest.Infrastructure.ServerFixtures;
@@ -60,6 +61,11 @@ protected override IHost CreateWebHost()
             args.Add(Environment);
         }
 
+        if (WebAssemblyTestHelper.MultithreadingIsEnabled())
+        {
+            args.Add("--apply-cop-headers");
+        }
+
         return DevHostServerProgram.BuildWebHost(args.ToArray());
     }
 

src/Components/test/testassets/Components.TestServer/AuthenticationStartup.cs

@@ -52,6 +52,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         // Mount the server-side Blazor app on /subdir
         app.Map("/subdir", app =>
         {
+            WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
             app.UseBlazorFrameworkFiles();
             app.UseStaticFiles();
 

src/Components/test/testassets/Components.TestServer/ClientStartup.cs

@@ -34,6 +34,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         app.Map("/subdir", app =>
         {
             // Add it before to ensure it takes priority over files in wwwroot
+            WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
             app.UseBlazorFrameworkFiles();
             app.UseStaticFiles();
 

src/Components/test/testassets/Components.TestServer/CorsStartup.cs

@@ -49,6 +49,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         // Mount the server-side Blazor app on /subdir
         app.Map("/subdir", app =>
         {
+            WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
             app.UseBlazorFrameworkFiles();
             app.UseStaticFiles();
 

src/Components/test/testassets/Components.TestServer/HotReloadStartup.cs

@@ -33,6 +33,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
             app.UseDeveloperExceptionPage();
         }
 
+        WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
         app.UseBlazorFrameworkFiles();
         app.UseStaticFiles();
         app.UseRouting();

src/Components/test/testassets/Components.TestServer/InternationalizationStartup.cs

@@ -34,6 +34,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         // Mount the server-side Blazor app on /subdir
         app.Map("/subdir", app =>
         {
+            WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
             app.UseBlazorFrameworkFiles();
             app.UseStaticFiles();
 

src/Components/test/testassets/Components.TestServer/MultipleComponents.cs

@@ -39,6 +39,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
 
         app.Map("/Client/multiple-components", app =>
         {
+            WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
             app.UseBlazorFrameworkFiles();
             app.UseStaticFiles();
             app.UseRouting();

src/Components/test/testassets/Components.TestServer/Program.cs

@@ -54,14 +54,21 @@ private static (IHost host, string basePath) CreateDevServerHost(string[] args)
         var contentRoot = typeof(Program).Assembly.GetCustomAttributes<AssemblyMetadataAttribute>()
             .Single(a => a.Key == "Microsoft.AspNetCore.InternalTesting.BasicTestApp.ContentRoot")
             .Value;
+        var finalArgs = new List<string>();
+        finalArgs.AddRange(args);
+        finalArgs.AddRange(
+        [
+            "--contentroot", contentRoot,
+            "--pathbase", "/subdir",
+            "--applicationpath", typeof(BasicTestApp.Program).Assembly.Location,
+        ]);
 
-        var finalArgs = args.Concat(new[]
+        if (WebAssemblyTestHelper.MultithreadingIsEnabled())
         {
-                "--contentroot", contentRoot,
-                "--pathbase", "/subdir",
-                "--applicationpath", typeof(BasicTestApp.Program).Assembly.Location,
-            }).ToArray();
-        var host = DevServerProgram.BuildWebHost(finalArgs);
+            finalArgs.Add("--apply-cop-headers");
+        }
+
+        var host = DevServerProgram.BuildWebHost(finalArgs.ToArray());
         return (host, "/subdir");
     }
 

src/Components/test/testassets/Components.TestServer/RazorComponentEndpointsStartup.cs

@@ -57,6 +57,8 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
 
         app.Map("/subdir", app =>
         {
+            WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
+
             if (!env.IsDevelopment())
             {
                 app.UseExceptionHandler("/Error", createScopeForErrors: true);

src/Components/test/testassets/Components.TestServer/SaveState.cs

@@ -37,6 +37,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
             app.UseDeveloperExceptionPage();
         }
 
+        WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
         app.UseBlazorFrameworkFiles();
         app.UseStaticFiles();
         app.UseRouting();

src/Components/test/testassets/Components.TestServer/StartupWithMapFallbackToClientSideBlazor.cs

@@ -33,6 +33,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         // The client-side files middleware needs to be here because the base href in hardcoded to /subdir/
         app.Map("/subdir", subApp =>
         {
+            WebAssemblyTestHelper.ServeCoopHeadersIfWebAssemblyThreadingEnabled(app);
             subApp.UseBlazorFrameworkFiles();
             subApp.UseStaticFiles();
 

src/Components/test/testassets/Components.TestServer/WebAssemblyTestHelper.cs

@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Reflection;
+
+namespace TestServer;
+
+public static class WebAssemblyTestHelper
+{
+    public static bool MultithreadingIsEnabled()
+    {
+        var entrypointAssembly = Assembly.GetExecutingAssembly();
+        var attribute = entrypointAssembly.GetCustomAttributes<AssemblyMetadataAttribute>()
+            .FirstOrDefault(x => x.Key.Equals("Microsoft.AspNetCore.InternalTesting.RunWebAssemblyE2ETestsWithMultithreading", StringComparison.Ordinal));
+        return attribute is not null && bool.Parse(attribute.Value);
+    }
+
+    public static void ServeCoopHeadersIfWebAssemblyThreadingEnabled(IApplicationBuilder app)
+    {
+        if (MultithreadingIsEnabled())
+        {
+            app.Use(async (ctx, next) =>
+            {
+                // Browser multi-threaded runtime requires cross-origin policy headers to enable SharedArrayBuffer.
+                ctx.Response.Headers.Append("Cross-Origin-Embedder-Policy", "require-corp");
+                ctx.Response.Headers.Append("Cross-Origin-Opener-Policy", "same-origin");
+                await next(ctx);
+            });
+        }
+    }
+}

src/Components/test/testassets/Directory.Build.props

@@ -3,5 +3,20 @@
 
   <PropertyGroup>
     <EnableTypeScriptNuGetTarget>true</EnableTypeScriptNuGetTarget>
+
+    <!--
+      This controls whether the WebAssembly E2E tests run with the multithreaded runtime or not.
+      It also implicitly sets an assembly metadata attribute so the test servers will serve the COOP
+      headers if and only if this flag is set. Note that until https://github.com/dotnet/runtime/issues/98502
+      is fixed, you will have to delete artifacts\obj directories after changing this flag.
+    -->
+    <!--<WasmEnableThreads>true</WasmEnableThreads>-->
   </PropertyGroup>
+
+  <ItemGroup>
+    <AssemblyAttribute Include="System.Reflection.AssemblyMetadataAttribute" Condition="'$(WasmEnableThreads)' == 'true'">
+      <_Parameter1>Microsoft.AspNetCore.InternalTesting.RunWebAssemblyE2ETestsWithMultithreading</_Parameter1>
+      <_Parameter2>true</_Parameter2>
+    </AssemblyAttribute>
+  </ItemGroup>
 </Project>