Fixed immediate value formatting in Group1 instruction handlers

X86DisassemblerTests/InstructionTests/AndInstructionTests.cs

@@ -0,0 +1,93 @@
+using X86Disassembler.X86;
+
+namespace X86DisassemblerTests.InstructionTests;
+
+/// <summary>
+/// Tests for AND instruction handlers
+/// </summary>
+public class AndInstructionTests
+{
+    /// <summary>
+    /// Tests the AndImmWithRm32Handler for decoding AND r/m32, imm32 instruction
+    /// </summary>
+    [Fact]
+    public void AndImmWithRm32Handler_DecodesAndRm32Imm32_Correctly()
+    {
+        // Arrange
+        // AND EAX, 0x12345678 (81 E0 78 56 34 12) - ModR/M byte E0 = 11 100 000 (mod=3, reg=4, rm=0)
+        // mod=3 means direct register addressing, reg=4 is the AND opcode extension, rm=0 is EAX
+        byte[] codeBuffer = new byte[] { 0x81, 0xE0, 0x78, 0x56, 0x34, 0x12 };
+        var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+        
+        // Act
+        var instruction = decoder.DecodeInstruction();
+        
+        // Assert
+        Assert.NotNull(instruction);
+        Assert.Equal("and", instruction.Mnemonic);
+        Assert.Equal("eax, 0x12345678", instruction.Operands);
+    }
+    
+    /// <summary>
+    /// Tests the AndImmWithRm32SignExtendedHandler for decoding AND r/m32, imm8 instruction
+    /// </summary>
+    [Fact]
+    public void AndImmWithRm32SignExtendedHandler_DecodesAndRm32Imm8_Correctly()
+    {
+        // Arrange
+        // AND EAX, 0x42 (83 E0 42) - ModR/M byte E0 = 11 100 000 (mod=3, reg=4, rm=0)
+        // mod=3 means direct register addressing, reg=4 is the AND opcode extension, rm=0 is EAX
+        byte[] codeBuffer = new byte[] { 0x83, 0xE0, 0x42 };
+        var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+        
+        // Act
+        var instruction = decoder.DecodeInstruction();
+        
+        // Assert
+        Assert.NotNull(instruction);
+        Assert.Equal("and", instruction.Mnemonic);
+        Assert.Equal("eax, 0x00000042", instruction.Operands);
+    }
+    
+    /// <summary>
+    /// Tests the AND r32, r/m32 instruction
+    /// </summary>
+    [Fact]
+    public void And_DecodesAndR32Rm32_Correctly()
+    {
+        // Arrange
+        // AND EAX, ECX (23 C1) - ModR/M byte C1 = 11 000 001 (mod=3, reg=0, rm=1)
+        // mod=3 means direct register addressing, reg=0 is EAX, rm=1 is ECX
+        byte[] codeBuffer = new byte[] { 0x23, 0xC1 };
+        var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+        
+        // Act
+        var instruction = decoder.DecodeInstruction();
+        
+        // Assert
+        Assert.NotNull(instruction);
+        Assert.Equal("and", instruction.Mnemonic);
+        Assert.Equal("eax, ecx", instruction.Operands);
+    }
+    
+    /// <summary>
+    /// Tests the AND r/m32, r32 instruction
+    /// </summary>
+    [Fact]
+    public void And_DecodesAndRm32R32_Correctly()
+    {
+        // Arrange
+        // AND ECX, EAX (21 C1) - ModR/M byte C1 = 11 000 001 (mod=3, reg=0, rm=1)
+        // mod=3 means direct register addressing, reg=0 is EAX, rm=1 is ECX
+        byte[] codeBuffer = new byte[] { 0x21, 0xC1 };
+        var decoder = new InstructionDecoder(codeBuffer, codeBuffer.Length);
+        
+        // Act
+        var instruction = decoder.DecodeInstruction();
+        
+        // Assert
+        Assert.NotNull(instruction);
+        Assert.Equal("and", instruction.Mnemonic);
+        Assert.Equal("ecx, eax", instruction.Operands);
+    }
+}