Make BundlerConsistencyTests stop building/copying self-contained project unnecessarily (#91829)

`BundlerConsistencyTests` were building a self-contained project and copying it for each test case. They are targeting the `Bundler` API and don't actual need a full app - just validation of how things get bundled and added to the manifest.
- Add a `HelloWorld` project for as a pre-built test asset for host tests
- Make `BundlerConsistencyTests` use a pre-built app and shared framework files instead of building/copying a self-contained project
- Move the one test `TestWithAdditionalContentAfterBundleMetadata` that actually runs the bundled app into `BundleAndRun`

Author: elinor-fung

eng/Subsets.props

@@ -489,6 +489,7 @@
   <!-- Host.pretest subset (consumes live built libraries assets so needs to come after libraries) -->
   <ItemGroup Condition="$(_subset.Contains('+host.pretest+'))">
     <ProjectToBuild Include="$(InstallerProjectRoot)tests\Assets\Projects\AppWithSubDirs\AppWithSubDirs.csproj" Category="host" />
+    <ProjectToBuild Include="$(InstallerProjectRoot)tests\Assets\Projects\HelloWorld\HelloWorld.csproj" Category="host" />
   </ItemGroup>
 
   <!-- Host.tests subset (consumes live built libraries assets so needs to come after libraries) -->

src/installer/tests/Assets/Projects/HelloWorld/HelloWorld.csproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
+    <OutputType>Exe</OutputType>
+  </PropertyGroup>
+
+</Project>

src/installer/tests/Assets/Projects/HelloWorld/Program.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.InteropServices;
+
+namespace HelloWorld
+{
+    public static class Program
+    {
+        public static void Main(string[] args)
+        {
+            Console.WriteLine("Hello World!");
+            Console.WriteLine(string.Join(Environment.NewLine, args));
+            Console.WriteLine(RuntimeInformation.FrameworkDescription);
+        }
+    }
+}

src/installer/tests/Microsoft.NET.HostModel.Tests/Microsoft.NET.HostModel.Bundle.Tests/BundleAndRun.cs

@@ -8,6 +8,7 @@
 using Microsoft.DotNet.CoreSetup.Test;
 using BundleTests.Helpers;
 using System.Runtime.InteropServices;
+using System.Text;
 
 namespace Microsoft.NET.HostModel.Tests
 {
@@ -120,6 +121,27 @@ public void TestWithRelativePathsDirSeparator()
             BundleRun(fixture, publishDir);
         }
 
+        [Fact]
+        public void TestWithAdditionalContentAfterBundleMetadata()
+        {
+            var fixture = sharedTestState.TestFixture.Copy();
+            string singleFile = BundleHelper.BundleApp(fixture);
+
+            using (var file = File.OpenWrite(singleFile))
+            {
+                file.Position = file.Length;
+                var blob = Encoding.UTF8.GetBytes("Mock signature at the end of the bundle");
+                file.Write(blob, 0, blob.Length);
+            }
+
+            Command.Create(singleFile)
+                .CaptureStdErr()
+                .CaptureStdOut()
+                .Execute()
+                .Should().Pass()
+                .And.HaveStdOutContaining("Hello World!");
+        }
+
         public class SharedTestState : IDisposable
         {
             public TestProjectFixture TestFixture { get; set; }

src/installer/tests/Microsoft.NET.HostModel.Tests/Microsoft.NET.HostModel.Bundle.Tests/BundlerConsistencyTests.cs

@@ -42,7 +42,7 @@ public static class AppHost
         public static class CoreClr
         {
             public static string FileName = GetSharedLibraryFileNameForCurrentPlatform("coreclr");
-            public static string FilePath = Path.Combine(RepoDirectoriesProvider.Default.HostArtifacts, FileName);
+            public static string FilePath = Path.Combine(new DotNetCli(RepoDirectoriesProvider.Default.BuiltDotnet).GreatestVersionSharedFxPath, FileName);
 
             public static string MockName = GetSharedLibraryFileNameForCurrentPlatform("mockcoreclr");
             public static string MockPath = Path.Combine(RepoDirectoriesProvider.Default.HostTestArtifacts, MockName);

src/installer/tests/TestUtils/Binaries.cs

@@ -60,6 +60,19 @@ private static SingleFileTestApp Create(string appName, bool selfContained)
             };
         }
 
+        public static IReadOnlyList<FileSpec> GetRuntimeFilesToBundle()
+        {
+            var runtimeAssemblies = Binaries.GetRuntimeFiles().Assemblies;
+            List<FileSpec> fileSpecs = new List<FileSpec>();
+            foreach (var asset in runtimeAssemblies)
+            {
+                fileSpecs.Add(new FileSpec(asset, Path.GetFileName(asset)));
+            }
+
+            fileSpecs.Sort((a, b) => string.CompareOrdinal(a.BundleRelativePath, b.BundleRelativePath));
+            return fileSpecs;
+        }
+
         public string Bundle(BundleOptions options, Version? bundleVersion = null)
         {
             string bundleDirectory = SharedFramework.CalculateUniqueTestDirectory(Path.Combine(Location, "bundle"));
@@ -81,11 +94,7 @@ public string Bundle(BundleOptions options, Version? bundleVersion = null)
             // If this is a self-contained app, add the runtime assemblies to the bundle
             if (selfContained)
             {
-                var runtimeAssemblies = Binaries.GetRuntimeFiles().Assemblies;
-                foreach (var asset in runtimeAssemblies)
-                {
-                    fileSpecs.Add(new FileSpec(asset, Path.GetFileName(asset)));
-                }
+                fileSpecs.AddRange(GetRuntimeFilesToBundle());
             }
 
             // Sort the file specs to keep the bundle construction deterministic.

src/installer/tests/TestUtils/SingleFileTestApp.cs

@@ -50,6 +50,15 @@ public static TestApp CreateEmpty(string name)
             };
         }
 
+        public static TestApp CreateFromBuiltAssets(string appName)
+        {
+            TestApp app = CreateEmpty(appName);
+            TestArtifact.CopyRecursive(
+                Path.Combine(RepoDirectoriesProvider.Default.TestAssetsOutput, appName),
+                app.Location);
+            return app;
+        }
+
         public void PopulateFrameworkDependent(string fxName, string fxVersion, Action<NetCoreAppBuilder> customizer = null)
         {
             var builder = NetCoreAppBuilder.PortableForNETCoreApp(this);