Host tests for using host-runtime contract

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

@@ -5,10 +5,7 @@
     <OutputType>Exe</OutputType>
     <RuntimeFrameworkVersion>$(MNAVersion)</RuntimeFrameworkVersion>
     <DefineConstants Condition="'$(OS)' == 'Windows_NT'">WINDOWS;$(DefineConstants)</DefineConstants>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
 
-  <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="$(NewtonsoftJsonVersion)" />
-  </ItemGroup>
-
 </Project>

src/installer/tests/Assets/TestProjects/HostApiInvokerApp/HostRuntimeContract.cs

@@ -0,0 +1,82 @@
+// 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.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace HostApiInvokerApp
+{
+    public static unsafe class HostRuntimeContract
+    {
+        internal struct host_runtime_contract
+        {
+            public void* context;
+            public IntPtr bundle_probe;
+            public IntPtr pinvoke_override;
+            public delegate* unmanaged[Stdcall]<byte*, byte*, nint, void*, nint> get_runtime_property;
+        }
+
+        private static host_runtime_contract GetContract()
+        {
+            string contractString = (string)AppContext.GetData("HOST_RUNTIME_CONTRACT");
+            if (string.IsNullOrEmpty(contractString))
+                throw new Exception("HOST_RUNTIME_CONTRACT not found");
+
+            host_runtime_contract* contract = (host_runtime_contract*)Convert.ToUInt64(contractString, 16);
+            return *contract;
+        }
+
+        private static void Test_get_runtime_property(string[] args)
+        {
+            host_runtime_contract contract = GetContract();
+
+            foreach (string name in args)
+            {
+                string value = GetProperty(name, contract);
+                Console.WriteLine($"{nameof(host_runtime_contract.get_runtime_property)}: {name} = {(value == null ? "<none>" : value)}");
+            }
+
+            static string GetProperty(string name, host_runtime_contract contract)
+            {
+                Span<byte> nameSpan = stackalloc byte[Encoding.UTF8.GetMaxByteCount(name.Length)];
+                byte* namePtr = (byte*)Unsafe.AsPointer(ref MemoryMarshal.GetReference(nameSpan));
+                int nameLen = Encoding.UTF8.GetBytes(name, nameSpan);
+                nameSpan[nameLen] = 0;
+
+                nint len = 256;
+                byte* buffer = stackalloc byte[(int)len];
+                nint lenActual = contract.get_runtime_property(namePtr, buffer, len, contract.context);
+                if (lenActual <= 0)
+                {
+                    Console.WriteLine($"No value for {name} - {nameof(host_runtime_contract.get_runtime_property)} returned {lenActual}");
+                    return null;
+                }
+
+                if (lenActual <= len)
+                    return Encoding.UTF8.GetString(buffer, (int)lenActual);
+
+                len = lenActual;
+                byte* expandedBuffer = stackalloc byte[(int)len];
+                lenActual = contract.get_runtime_property(namePtr, expandedBuffer, len, contract.context);
+                return Encoding.UTF8.GetString(expandedBuffer, (int)lenActual);
+            }
+        }
+
+        public static bool RunTest(string apiToTest, string[] args)
+        {
+            switch (apiToTest)
+            {
+                case $"{nameof(host_runtime_contract)}.{nameof(host_runtime_contract.get_runtime_property)}":
+                    Test_get_runtime_property(args);
+                    break;
+                default:
+                    return false;
+            }
+
+            return true;
+        }
+    }
+
+}

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

@@ -31,16 +31,13 @@ public static void MainCore(string[] args)
             Console.WriteLine("Hello World!");
             Console.WriteLine(string.Join(Environment.NewLine, args));
 
-            // A small operation involving NewtonSoft.Json to ensure the assembly is loaded properly
-            var t = typeof(Newtonsoft.Json.JsonReader);
-
             // Enable tracing so that test assertion failures are easier to diagnose.
             Environment.SetEnvironmentVariable("COREHOST_TRACE", "1");
 
             // If requested, test multilevel lookup using fake Global SDK directories:
             //     1. using a fake ProgramFiles location
             //     2. using a fake SDK Self-Registered location
-            // Note that this has to be set here and not in the calling test process because 
+            // Note that this has to be set here and not in the calling test process because
             // %ProgramFiles% gets reset on process creation.
             string testMultilevelLookupProgramFiles = Environment.GetEnvironmentVariable("TEST_MULTILEVEL_LOOKUP_PROGRAM_FILES");
             string testMultilevelLookupSelfRegistered = Environment.GetEnvironmentVariable("TEST_MULTILEVEL_LOOKUP_SELF_REGISTERED");
@@ -65,17 +62,15 @@ public static void MainCore(string[] args)
 
             string apiToTest = args[0];
             if (HostFXR.RunTest(apiToTest, args))
-            {
                 return;
-            }
-            else if (HostPolicy.RunTest(apiToTest, args))
-            {
+
+            if (HostPolicy.RunTest(apiToTest, args))
                 return;
-            }
-            else
-            {
-                throw new ArgumentException($"Invalid API to test passed as args[0]): {apiToTest}");
-            }
+
+            if (HostRuntimeContract.RunTest(apiToTest, args))
+                return;
+
+            throw new ArgumentException($"Invalid API to test passed as args[0]): {apiToTest}");
         }
     }
 }

src/installer/tests/HostActivation.Tests/NativeHostApis.cs

@@ -473,6 +473,21 @@ public void Hostpolicy_corehost_set_error_writer_test()
                 .Should().Pass();
         }
 
+        [Fact]
+        public void HostRuntimeContract_get_runtime_property()
+        {
+            var fixture = sharedTestState.HostApiInvokerAppFixture;
+
+            fixture.BuiltDotnet.Exec(fixture.TestProject.AppDll, "host_runtime_contract.get_runtime_property", "APP_CONTEXT_BASE_DIRECTORY", "ENTRY_ASSEMBLY_NAME", "DOES_NOT_EXIST")
+                .CaptureStdOut()
+                .CaptureStdErr()
+                .Execute()
+                .Should().Pass()
+                .And.HaveStdOutContaining($"APP_CONTEXT_BASE_DIRECTORY = {Path.GetDirectoryName(fixture.TestProject.AppDll)}")
+                .And.HaveStdOutContaining($"ENTRY_ASSEMBLY_NAME = {fixture.TestProject.AssemblyName}")
+                .And.HaveStdOutContaining($"DOES_NOT_EXIST = <none>");
+        }
+
         public class SharedTestState : IDisposable
         {
             public TestProjectFixture HostApiInvokerAppFixture { get; }