Adding Microsoft.AspNetCore.EnsureJsonTrimmability host configuration

sdk.sln

@@ -411,6 +411,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.DotNet.GenAPI", "
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.DotNet.GenAPI.Task", "src\GenAPI\Microsoft.DotNet.GenAPI.Task\Microsoft.DotNet.GenAPI.Task.csproj", "{C419AE2D-D318-49EB-8ECA-6A5DC13FE4EA}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.NET.Sdk.Web.Tests", "src\Tests\Microsoft.NET.Sdk.Web.Tests\Microsoft.NET.Sdk.Web.Tests.csproj", "{B8A61A5C-A9A4-45C5-97E3-CB368358682F}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -793,6 +795,10 @@ Global
 		{C419AE2D-D318-49EB-8ECA-6A5DC13FE4EA}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{C419AE2D-D318-49EB-8ECA-6A5DC13FE4EA}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C419AE2D-D318-49EB-8ECA-6A5DC13FE4EA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B8A61A5C-A9A4-45C5-97E3-CB368358682F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B8A61A5C-A9A4-45C5-97E3-CB368358682F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B8A61A5C-A9A4-45C5-97E3-CB368358682F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B8A61A5C-A9A4-45C5-97E3-CB368358682F}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -937,6 +943,7 @@ Global
 		{E2BC296E-2660-4692-B471-F6FCD4C19F6E} = {580D1AE7-AA8F-4912-8B76-105594E00B3B}
 		{5F74AD67-A4AD-4660-A63C-844DAAF354C4} = {95D8B040-FD7F-4C86-8E47-341AF630EDA9}
 		{C419AE2D-D318-49EB-8ECA-6A5DC13FE4EA} = {95D8B040-FD7F-4C86-8E47-341AF630EDA9}
+		{B8A61A5C-A9A4-45C5-97E3-CB368358682F} = {580D1AE7-AA8F-4912-8B76-105594E00B3B}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {FB8F26CE-4DE6-433F-B32A-79183020BBD6}

src/Tests/Microsoft.NET.Sdk.Web.Tests/Microsoft.NET.Sdk.Web.Tests.csproj

@@ -0,0 +1,31 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <EnableDefaultItems>false</EnableDefaultItems>
+    <OutDirName>Tests\$(MSBuildProjectName)</OutDirName>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <TargetFramework>$(SdkTargetFramework)</TargetFramework>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <PackageId>testSdkWeb</PackageId>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="**\*.cs" Exclude="$(GlobalExclude)" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="FluentAssertions.Json" Version="$(FluentAssertionsJsonVersion)" />
+    <PackageReference Include="System.Reflection.MetadataLoadContext" Version="$(SystemReflectionMetadataLoadContextVersion)" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Microsoft.NET.TestFramework\Microsoft.NET.TestFramework.csproj" />
+    <ProjectReference Include="..\..\..\src\WebSdk\Web\Tasks\Microsoft.NET.Sdk.Web.Tasks.csproj" />
+  </ItemGroup>
+
+</Project>

src/Tests/Microsoft.NET.Sdk.Web.Tests/PublishTests.cs

@@ -0,0 +1,103 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Collections.Generic;
+using System.IO;
+using System.Text.Json.Nodes;
+using FluentAssertions;
+using Microsoft.NET.TestFramework;
+using Microsoft.NET.TestFramework.Assertions;
+using Microsoft.NET.TestFramework.Commands;
+using Microsoft.NET.TestFramework.ProjectConstruction;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Microsoft.NET.Sdk.Web.Tests
+{
+    public class PublishTests : SdkTest
+    {
+        public PublishTests(ITestOutputHelper log) : base(log)
+        {
+        }
+
+        [Theory()]
+        [MemberData(nameof(SupportedTfms))]
+        public void TrimmingOptions_Are_Defaulted_Correctly_On_Trimmed_Apps(string targetFramework)
+        {
+            var projectName = "HelloWorld";
+            var rid = EnvironmentInfo.GetCompatibleRid(targetFramework);
+
+            var testProject = CreateTestProjectForILLinkTesting(targetFramework, projectName);
+            testProject.AdditionalProperties["PublishTrimmed"] = "true";
+
+            var testAsset = _testAssetsManager.CreateTestProject(testProject, identifier: projectName + targetFramework);
+
+            var publishCommand = new PublishCommand(Log, Path.Combine(testAsset.TestRoot, testProject.Name));
+            publishCommand.Execute($"/p:RuntimeIdentifier={rid}").Should().Pass();
+
+            string outputDirectory = publishCommand.GetOutputDirectory(targetFramework: targetFramework, runtimeIdentifier: rid).FullName;
+            string runtimeConfigFile = Path.Combine(outputDirectory, $"{projectName}.runtimeconfig.json");
+            string runtimeConfigContents = File.ReadAllText(runtimeConfigFile);
+
+            JsonNode runtimeConfig = JsonNode.Parse(runtimeConfigContents);
+            JsonNode configProperties = runtimeConfig["runtimeOptions"]["configProperties"];
+
+            configProperties["Microsoft.AspNetCore.EnsureJsonTrimmability"].GetValue<bool>()
+                    .Should().BeTrue();
+        }
+
+        [Theory()]
+        [MemberData(nameof(SupportedTfms))]
+        public void TrimmingOptions_Are_Defaulted_Correctly_On_Aot_Apps(string targetFramework)
+        {
+            var projectName = "HelloWorld";
+            var rid = EnvironmentInfo.GetCompatibleRid(targetFramework);
+
+            var testProject = CreateTestProjectForILLinkTesting(targetFramework, projectName);
+            testProject.AdditionalProperties["PublishAOT"] = "true";
+
+            var testAsset = _testAssetsManager.CreateTestProject(testProject, identifier: projectName + targetFramework);
+            var publishCommand = new PublishCommand(Log, Path.Combine(testAsset.TestRoot, testProject.Name));
+            publishCommand.Execute($"/p:RuntimeIdentifier={rid}").Should().Pass();
+
+            string outputDirectory = publishCommand.GetIntermediateDirectory(targetFramework: targetFramework, runtimeIdentifier: rid).FullName;
+            string responseFile = Path.Combine(outputDirectory, "native", $"{projectName}.ilc.rsp");
+            var responseFileContents = File.ReadLines(responseFile);
+
+            responseFileContents.Should().Contain("--feature:Microsoft.AspNetCore.EnsureJsonTrimmability=true");
+        }
+
+        public static IEnumerable<object[]> SupportedTfms { get; } = new List<object[]>
+        {
+#if NET8_0
+            new object[] { ToolsetInfo.CurrentTargetFramework }
+#else
+#error If building for a newer TFM, please update the values above
+#endif
+        };
+
+        private TestProject CreateTestProjectForILLinkTesting(
+            string targetFramework,
+            string projectName)
+        {
+            var testProject = new TestProject()
+            {
+                Name = projectName,
+                TargetFrameworks = targetFramework,
+                IsExe = true,
+                ProjectSdk = "Microsoft.NET.Sdk.Web"
+            };
+
+            testProject.SourceFiles[$"Program.cs"] = """
+                using Microsoft.AspNetCore.Builder;
+                using Microsoft.Extensions.Hosting;
+
+                var builder = WebApplication.CreateBuilder();
+                var app = builder.Build();
+                app.Start();
+                """;
+
+            return testProject;
+        }
+    }
+}

src/WebSdk/ProjectSystem/Targets/Microsoft.NET.Sdk.Web.ProjectSystem.targets

@@ -46,6 +46,12 @@ Copyright (c) .NET Foundation. All rights reserved.
     <EnableUnsafeBinaryFormatterSerialization Condition="'$(EnableUnsafeBinaryFormatterSerialization)' == ''">false</EnableUnsafeBinaryFormatterSerialization>
   </PropertyGroup>
 
+
+  <PropertyGroup Condition="'$(PublishTrimmed)' == 'true' Or '$(PublishAot)' == 'true'">
+    <!-- Runtime feature defaults to trim unnecessary code -->
+    <EnsureAspNetCoreJsonTrimmability Condition="'$(EnsureAspNetCoreJsonTrimmability)' == ''">true</EnsureAspNetCoreJsonTrimmability>
+  </PropertyGroup>
+
   <!--
     Newer versions of Visual Studio ship the designtime related properties in a targets file and all future design time only elements should be added there. If that file does not
     exist, it falls back to the default set of values defined here.

src/WebSdk/Web/Sdk/Sdk.targets

@@ -30,4 +30,18 @@ Copyright (c) .NET Foundation. All rights reserved.
 
   <Import Sdk="Microsoft.NET.Sdk.Publish" Project="Sdk.targets" />
 
+  <!--
+  ============================================================
+    DefaultRuntimeHostConfigurationOptions
+  Defaults @(RuntimeHostConfigurationOption) items based on MSBuild properties.
+  ============================================================
+  -->
+
+  <ItemGroup>
+    <RuntimeHostConfigurationOption Include="Microsoft.AspNetCore.EnsureJsonTrimmability"
+                                    Condition="'$(EnsureAspNetCoreJsonTrimmability)' != ''"
+                                    Value="$(EnsureAspNetCoreJsonTrimmability)"
+                                    Trim="true" />
+  </ItemGroup>
+
 </Project>