test: Add tests for all control instructions and base CPU implementation

1 files changed, 87 insertions, 0 deletions

diff --git a/Q1.tests/Core/ChipTests.cs b/Q1.tests/Core/ChipTests.cs
new file mode 100644
index 0000000..2b0d20f
--- /dev/null
+++ b/Q1.tests/Core/ChipTests.cs
@@ -0,0 +1,87 @@
+namespace Q1.tests.Core;
+
+using core.Arch;
+using core.Arch.Constants;
+
+[TestFixture]
+public class ChipTests : ChipTestBase
+{
+    [TestCase(ChipRegisters.AX)]
+    [TestCase(ChipRegisters.DX)]
+    [TestCase(ChipRegisters.LX)]
+    public void Register_ShouldRoundTrip(u8 register)
+    {
+        var chip = this.CreateChip();
+
+        u16 value = (u16) (register * 0x1111); // unique value for each register
+        chip.SetRegister(register, value);
+        u16 readValue = chip.GetRegister(register);
+
+        Assert.That(readValue, Is.EqualTo(value), $"Register {register:X2} should round trip");
+    }
+
+    [Test]
+    public void PushPop_ShouldRoundTrip()
+    {
+        var chip = this.CreateChip();
+
+        u16 value = 0xABCD;
+        chip.Push(value);
+        u16 poppedValue = chip.Pop();
+
+        Assert.That(poppedValue, Is.EqualTo(value), "Popped value should match pushed value");
+    }
+
+    [Test]
+    public void StackOverflow_ShouldThrow()
+    {
+        var chip = this.CreateChip();
+
+        // Fill the stack to its limit
+        for (int i = 0; i < ChipLayout.STACK_COUNT; i++)
+            chip.Push((u16) i);
+
+        // Next push should cause overflow
+        Assert.Throws<InvalidOperationException>(() => chip.Push(0xFFFF), "Expected stack overflow to throw");
+    }
+
+    [Test]
+    public void StackUnderflow_ShouldThrow()
+    {
+        var chip = this.CreateChip();
+        
+        // Attempt to pop from an empty stack
+        Assert.Throws<InvalidOperationException>(() => chip.Pop(), "Expected stack underflow to throw");
+    }
+    
+    [Test]
+    public void InvalidRegisterAccess_ShouldThrow()
+    {
+        var chip = this.CreateChip();
+        
+        // Attempt to access an invalid register index
+        Assert.Throws<InvalidOperationException>(() => chip.GetRegister(0xFF), "Expected invalid register access to throw");
+        Assert.Throws<InvalidOperationException>(() => chip.SetRegister(0xFF, 0x1234), "Expected invalid register access to throw");
+    }
+    
+    [Test]
+    public void InterruptHandling_ShouldJumpToInterruptVector()
+    {
+        var chip = this.CreateChip();
+
+        var originalPc = chip.Pc;
+        
+        // Set up an interrupt vector at 0xFFFE
+        u16 interruptHandlerAddress = 0x1234;
+        chip.RegisterInterruptHandler(8, interruptHandlerAddress); // Register handler for interrupt 8
+        
+        // Trigger the interrupt
+        chip.Interrupt(8);
+        
+        Assert.Multiple(() =>
+        {
+            Assert.That(chip.Pc, Is.EqualTo(interruptHandlerAddress), "PC should jump to interrupt handler address");
+            Assert.That(chip.Pop(), Is.EqualTo(originalPc), "PC should be pushed onto the stack during interrupt");
+        });
+    }
+}
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