Add new test ReflectionAddNewMethod

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewMethod/ReflectionAddNewMethod.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+
+
+namespace System.Reflection.Metadata.ApplyUpdate.Test
+{
+    public class ReflectionAddNewMethod
+    {
+        public string ExistingMethod(string u, double f)
+	{
+            return u + f.ToString();;
+        }
+
+    }
+}

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewMethod/ReflectionAddNewMethod_v1.cs

@@ -0,0 +1,21 @@
+// 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 CancellationToken = System.Threading.CancellationToken;
+
+namespace System.Reflection.Metadata.ApplyUpdate.Test
+{
+    public class ReflectionAddNewMethod
+    {
+        public string ExistingMethod(string u, double f)
+	{
+            return u + f.ToString();;
+        }
+
+	public double AddedNewMethod(char c, float h, string w, CancellationToken ct = default, [CallerMemberName] string callerName = "")
+	{
+	    return ((double)Convert.ToInt32(c)) + h;
+	}
+    }
+}

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewMethod/System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewMethod.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <RootNamespace>System.Runtime.Loader.Tests</RootNamespace>
+    <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
+    <TestRuntime>true</TestRuntime>
+    <DeltaScript>deltascript.json</DeltaScript>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="ReflectionAddNewMethod.cs" />
+  </ItemGroup>
+</Project>

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewMethod/deltascript.json

@@ -0,0 +1,6 @@
+{
+    "changes": [
+        {"document": "ReflectionAddNewMethod.cs", "update": "ReflectionAddNewMethod_v1.cs"},
+    ]
+}
+

src/libraries/System.Runtime.Loader/tests/ApplyUpdateTest.cs

@@ -629,5 +629,52 @@ public static void TestReflectionAddNewType()
                 System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewType.ZExistingClass.ExistingMethod ();
             });
         }
+
+        [ConditionalFact(typeof(ApplyUpdateUtil), nameof(ApplyUpdateUtil.IsSupported))]
+        public static void TestReflectionAddNewMethod()
+        {
+            ApplyUpdateUtil.TestCase(static () =>
+            {
+		var ty = typeof(System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewMethod);
+                var assm = ty.Assembly;
+
+                var allMethods = ty.GetMethods();
+
+		foreach (var m in allMethods) {
+		    Console.WriteLine ($"method: {m.Name}");
+		}
+		const int objectMethods = 4;
+		Assert.Equal (objectMethods + 1, allMethods.Length);
+
+                ApplyUpdateUtil.ApplyUpdate(assm);
+
+		allMethods = ty.GetMethods();
+		Assert.Equal (objectMethods + 2, allMethods.Length);
+
+		var mi = ty.GetMethod ("AddedNewMethod");
+
+		Assert.NotNull (mi);
+
+		var retParm = mi.ReturnParameter;
+		Assert.NotNull (retParm);
+		Console.WriteLine ($"return parm: {retParm}");
+		var retCas = retParm.GetCustomAttributes();
+		foreach (var rca in retCas) {
+		    Console.WriteLine ($" - ca: {rca}");
+		}
+
+		var parms = mi.GetParameters();
+
+		foreach (var parm in parms) {
+		    Console.WriteLine ($"parm: {parm}");
+		    var cas = parm.GetCustomAttributes();
+		    foreach (var ca in cas) {
+			Console.WriteLine ($" - ca: {ca}");
+		    }
+		}
+
+		Assert.Equal (5, parms.Length);
+	    });
+	} 
     }
 }

src/libraries/System.Runtime.Loader/tests/System.Runtime.Loader.Tests.csproj

@@ -62,6 +62,7 @@
     <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda\System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda.csproj" />
     <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.StaticLambdaRegression\System.Reflection.Metadata.ApplyUpdate.Test.StaticLambdaRegression.csproj" />
     <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewType\System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewType.csproj" />
+    <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewMethod\System.Reflection.Metadata.ApplyUpdate.Test.ReflectionAddNewMethod.csproj" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetOS)' == 'Browser'">
     <WasmFilesToIncludeFromPublishDir Include="$(AssemblyName).dll" />