From b663c54bda358110df2f7bcc53cf3b0310ab0285 Mon Sep 17 00:00:00 2001
From: "Eric P. Nusbaum" <eric@enusbaum.com>
Date: Sat, 15 Jul 2023 18:29:14 -0400
Subject: [PATCH] Unit Tests for CPU `NEG` Opcode

---
 MBBSEmu.Tests/CPU/NEG_Tests.cs | 58 ++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 MBBSEmu.Tests/CPU/NEG_Tests.cs

diff --git a/MBBSEmu.Tests/CPU/NEG_Tests.cs b/MBBSEmu.Tests/CPU/NEG_Tests.cs
new file mode 100644
index 00000000..336dd894
--- /dev/null
+++ b/MBBSEmu.Tests/CPU/NEG_Tests.cs
@@ -0,0 +1,58 @@
+using Iced.Intel;
+using Xunit;
+using static Iced.Intel.AssemblerRegisters;
+
+namespace MBBSEmu.Tests.CPU
+{
+    public class NEG_Tests : CpuTestBase
+    {
+        //Unit Tests using xUnit to perform testing of the NEG opcode in CPUCore
+        [Theory]
+        [InlineData(0x00, 0x00, false, false)]
+        [InlineData(0x01, 0xFF, true, true)]
+        [InlineData(0x7F, 0x81, true, true)]
+        [InlineData(0x80, 0x80, true, true)]
+        [InlineData(0xFF, 0x01, false, true)]
+        [InlineData(0x81, 0x7F, false, true)]
+        public void NEG_8_Register_Test(byte input, byte expectedValue, bool expectedSF, bool expectedCF)
+        {
+            Reset();
+            mbbsEmuCpuRegisters.AL = input;
+
+            var instructions = new Assembler(16);
+            instructions.neg(al);
+            CreateCodeSegment(instructions);
+
+            mbbsEmuCpuCore.Tick();
+
+            Assert.Equal(expectedValue, mbbsEmuCpuRegisters.AL);
+            Assert.Equal(expectedSF, mbbsEmuCpuRegisters.SignFlag);
+            Assert.Equal(expectedCF, mbbsEmuCpuRegisters.CarryFlag);
+        }
+
+        //16bit Register Unit Tests for NEG
+        [Theory]
+        [InlineData(0x0000, 0x0000, false, false)]
+        [InlineData(0x0001, 0xFFFF, true, true)]
+        [InlineData(0x7FFF, 0x8001, true, true)]
+        [InlineData(0x8000, 0x8000, true, true)]
+        [InlineData(0xFFFF, 0x0001, false, true)]
+        [InlineData(0x8001, 0x7FFF, false, true)]
+        public void NEG_16_Register_Test(ushort input, ushort expectedValue, bool expectedSF, bool expectedCF)
+        {
+            Reset();
+            mbbsEmuCpuRegisters.AX = input;
+
+            var instructions = new Assembler(16);
+            instructions.neg(ax);
+            CreateCodeSegment(instructions);
+
+            mbbsEmuCpuCore.Tick();
+
+            Assert.Equal(expectedValue, mbbsEmuCpuRegisters.AX);
+            Assert.Equal(expectedSF, mbbsEmuCpuRegisters.SignFlag);
+            Assert.Equal(expectedCF, mbbsEmuCpuRegisters.CarryFlag);
+        }
+
+    }
+}