Reduce test projects and remove usage of Newtonsoft.Json in StartupHo…

…ok tests (#84652)

src/installer/tests/Assets/TestProjects/PortableApp/PortableApp.csproj

@@ -6,8 +6,4 @@
     <RuntimeFrameworkVersion>$(MNAVersion)</RuntimeFrameworkVersion>
   </PropertyGroup>
 
-  <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="$(NewtonsoftJsonVersion)" />
-  </ItemGroup>
-
 </Project>

src/installer/tests/Assets/TestProjects/PortableApp/Program.cs

@@ -2,7 +2,9 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Runtime.Loader;
 
 namespace PortableApp
 {
@@ -14,9 +16,15 @@ public static void Main(string[] args)
             Console.WriteLine(string.Join(Environment.NewLine, args));
             Console.WriteLine(RuntimeInformation.FrameworkDescription);
 
-            // A small operation involving NewtonSoft.Json to ensure the assembly is loaded properly
-            var t = typeof(Newtonsoft.Json.JsonReader);
-            System.Diagnostics.Trace.WriteLine(t);
+            if (args.Length == 0)
+                return;
+
+            if (args[0] == "load_shared_library")
+            {
+                var asm = AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName("SharedLibrary"));
+                FieldInfo field = asm.GetType("SharedLibrary.SharedType").GetField("Value");
+                Console.WriteLine($"SharedLibrary.SharedType.Value={field.GetValue(null)}");
+            }
         }
     }
 }

src/installer/tests/Assets/TestProjects/StartupHookWithAssemblyResolver/StartupHookWithAssemblyResolver.cs

@@ -4,29 +4,42 @@
 using System;
 using System.IO;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using System.Runtime.Loader;
 
 internal class StartupHook
 {
     public static void Initialize()
     {
-        AssemblyLoadContext.Default.Resolving += SharedHostPolicy.SharedAssemblyResolver.Resolve;
+        Console.WriteLine($"Hello from startup hook in {(typeof(StartupHook).Assembly.GetName().Name)}!");
+
+        bool addResolver = Environment.GetEnvironmentVariable("TEST_STARTUPHOOK_ADD_RESOLVER") == true.ToString();
+        if (addResolver)
+        {
+            AssemblyLoadContext.Default.Resolving += OnResolving;
+        }
+
+        bool useDependency = Environment.GetEnvironmentVariable("TEST_STARTUPHOOK_USE_DEPENDENCY") == true.ToString();
+        if (useDependency)
+        {
+            UseDependency();
+        }
     }
-}
 
-namespace SharedHostPolicy
-{
-    public class SharedAssemblyResolver
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static void UseDependency()
     {
-        public static Assembly Resolve(AssemblyLoadContext context, AssemblyName assemblyName)
-        {
-            if (assemblyName.Name == "SharedLibrary")
-            {
-                string startupHookDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
-                string sharedLibrary = Path.GetFullPath(Path.Combine(startupHookDirectory, "SharedLibrary.dll"));
-                return AssemblyLoadContext.Default.LoadFromAssemblyPath(sharedLibrary);
-            }
+        Console.WriteLine($"SharedLibrary.Value: {SharedLibrary.SharedType.Value}");
+    }
+
+    private static Assembly OnResolving(AssemblyLoadContext context, AssemblyName assemblyName)
+    {
+        if (assemblyName.Name != "SharedLibrary")
             return null;
-        }
+
+        Console.WriteLine($"Resolving {assemblyName.Name} in startup hook");
+        string startupHookDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
+        string sharedLibrary = Path.GetFullPath(Path.Combine(startupHookDirectory, "SharedLibrary.dll"));
+        return AssemblyLoadContext.Default.LoadFromAssemblyPath(sharedLibrary);
     }
 }