From cce42102182382b601c88a839e41fa16d92f5c2b Mon Sep 17 00:00:00 2001
From: Jerome Haltom <jhaltom@alethic.solutions>
Date: Fri, 13 Dec 2024 13:21:12 -0600
Subject: [PATCH] Add an object test. Add a basic runtime test which generates
 byte code. These probably need to be sorted more.

---
 src/IKVM.Tests/Java/java/lang/ObjectTests.cs | 11 ++-
 src/IKVM.Tests/Runtime/RuntimeTests.cs       | 94 ++++++++++++++++++++
 2 files changed, 103 insertions(+), 2 deletions(-)
 create mode 100644 src/IKVM.Tests/Runtime/RuntimeTests.cs

diff --git a/src/IKVM.Tests/Java/java/lang/ObjectTests.cs b/src/IKVM.Tests/Java/java/lang/ObjectTests.cs
index 97a7c7ca61..0d3cc90d2d 100644
--- a/src/IKVM.Tests/Java/java/lang/ObjectTests.cs
+++ b/src/IKVM.Tests/Java/java/lang/ObjectTests.cs
@@ -1,4 +1,6 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using FluentAssertions;
+
+using Microsoft.VisualStudio.TestTools.UnitTesting;
 
 namespace IKVM.Tests.Java.java.lang
 {
@@ -7,7 +9,12 @@ namespace IKVM.Tests.Java.java.lang
     public class ObjectTests
     {
 
-
+        [TestMethod]
+        public void CanCreateObject()
+        {
+            var o = new global::java.lang.Object();
+            o.Should().BeOfType<global::java.lang.Object>();
+        }
 
     }
 
diff --git a/src/IKVM.Tests/Runtime/RuntimeTests.cs b/src/IKVM.Tests/Runtime/RuntimeTests.cs
new file mode 100644
index 0000000000..e41a4076ba
--- /dev/null
+++ b/src/IKVM.Tests/Runtime/RuntimeTests.cs
@@ -0,0 +1,94 @@
+using System;
+
+using FluentAssertions;
+
+using IKVM.ByteCode;
+using IKVM.ByteCode.Buffers;
+using IKVM.ByteCode.Encoding;
+
+using java.lang;
+
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace IKVM.Tests.Runtime
+{
+
+    [TestClass]
+    public class RuntimeTests
+    {
+
+        /// <summary>
+        /// Simple <see cref="ClassLoader"/> implementation that loads a class from a builder.
+        /// </summary>
+        class ByteArrayClassLoader : ClassLoader
+        {
+
+            /// <summary>
+            /// Loads the specified <see cref="ClassFileBuilder"/> as a class.
+            /// </summary>
+            /// <param name="clazz"></param>
+            /// <param name="name"></param>
+            /// <returns></returns>
+            public Class Load(ClassFileBuilder clazz, string name)
+            {
+                var clazzBuffer = new BlobBuilder();
+                clazz.Serialize(clazzBuffer);
+                return defineClass(name, clazzBuffer.ToArray(), 0, clazzBuffer.Count);
+            }
+
+        }
+
+        /// <summary>
+        /// Adds a method and code.
+        /// </summary>
+        /// <param name="clazz"></param>
+        /// <param name="flags"></param>
+        /// <param name="name"></param>
+        /// <param name="signature"></param>
+        /// <param name="code"></param>
+        /// <param name="maxStack"></param>
+        /// <param name="maxLocals"></param>
+        void AddMethod(ClassFileBuilder clazz, AccessFlag flags, string name, string signature, Action<CodeBuilder> code, ushort maxStack, ushort maxLocals)
+        {
+            var attributes = new AttributeTableBuilder(clazz.Constants);
+            var buffer = new BlobBuilder();
+            code(new CodeBuilder(buffer));
+            attributes.Code(maxStack, maxLocals, buffer, e => { }, null);
+            clazz.AddMethod(flags, name, signature, attributes);
+        }
+
+        /// <summary>
+        /// Adds a default constrctor.
+        /// </summary>
+        /// <param name="clazz"></param>
+        void AddDefaultConstructor(ClassFileBuilder clazz)
+        {
+            AddMethod(clazz, AccessFlag.Public, "<init>", "()V", c => c
+                .Aload0()
+                .InvokeSpecial(clazz.Constants.GetOrAddMethodref(clazz.Constants.GetOrAddClass("java/lang/Object"), clazz.Constants.GetOrAddNameAndType("<init>", "()V")))
+                .Return(), 1, 1);
+        }
+
+        [TestMethod]
+        public void NewDupInvokeSpecialAReturn()
+        {
+            var builder = new ClassFileBuilder(52, AccessFlag.Public, "Test", "java/lang/Object");
+            AddDefaultConstructor(builder);
+            AddMethod(builder, AccessFlag.Public | AccessFlag.Static, "CreateObject", "()Ljava/lang/Object;", c => c
+                .New(builder.Constants.GetOrAddClass("java/lang/Object"))
+                .Dup()
+                .InvokeSpecial(builder.Constants.GetOrAddMethodref(builder.Constants.GetOrAddClass("java/lang/Object"), builder.Constants.GetOrAddNameAndType("<init>", "()V")))
+                .Areturn(), 2, 0);
+
+            var cldr = new ByteArrayClassLoader();
+            var clazz = cldr.Load(builder, "Test");
+
+            var instance = clazz.newInstance();
+            var method = clazz.getMethod("CreateObject", []);
+            var result = method.invoke(instance, []);
+            result.Should().BeOfType<global::java.lang.Object>();
+        }
+
+    }
+
+}