Added OrRm8R8Handler for decoding OR r/m8, r8 instruction (opcode 0x08)

X86DisassemblerTests/OrRm8R8HandlerTests.cs

@@ -0,0 +1,72 @@
+namespace X86DisassemblerTests;
+
+using System;
+using Xunit;
+using X86Disassembler.X86;
+using X86Disassembler.X86.Handlers.Or;
+
+/// <summary>
+/// Tests for OR r/m8, r8 instruction handler
+/// </summary>
+public class OrRm8R8HandlerTests
+{
+    /// <summary>
+    /// Tests the OrRm8R8Handler for decoding OR [mem], reg8 instruction
+    /// </summary>
+    [Fact]
+    public void OrRm8R8Handler_DecodesOrMemReg8_Correctly()
+    {
+        // Arrange
+        // OR [ebx+ecx*4+0x41], al (08 44 8B 41)
+        byte[] codeBuffer = new byte[] { 0x08, 0x44, 0x8B, 0x41 };
+        var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+        
+        // Act
+        var instruction = decoder.DecodeInstruction();
+        
+        // Assert
+        Assert.NotNull(instruction);
+        Assert.Equal("or", instruction.Mnemonic);
+        Assert.Equal("byte ptr [ebx+ecx*4+0x41], al", instruction.Operands);
+    }
+    
+    /// <summary>
+    /// Tests the OrRm8R8Handler for decoding OR reg8, reg8 instruction
+    /// </summary>
+    [Fact]
+    public void OrRm8R8Handler_DecodesOrRegReg8_Correctly()
+    {
+        // Arrange
+        // OR bl, ch (08 EB)
+        byte[] codeBuffer = new byte[] { 0x08, 0xEB };
+        var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+        
+        // Act
+        var instruction = decoder.DecodeInstruction();
+        
+        // Assert
+        Assert.NotNull(instruction);
+        Assert.Equal("or", instruction.Mnemonic);
+        Assert.Equal("bl, ch", instruction.Operands);
+    }
+    
+    /// <summary>
+    /// Tests the OrRm8R8Handler for handling insufficient bytes
+    /// </summary>
+    [Fact]
+    public void OrRm8R8Handler_HandlesInsufficientBytes_Gracefully()
+    {
+        // Arrange
+        // OR ?? (08) - missing ModR/M byte
+        byte[] codeBuffer = new byte[] { 0x08 };
+        var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+        
+        // Act
+        var instruction = decoder.DecodeInstruction();
+        
+        // Assert
+        Assert.NotNull(instruction);
+        Assert.Equal("or", instruction.Mnemonic);
+        Assert.Equal("??", instruction.Operands);
+    }
+}