From 5290a9d61ed0ce56277890b0277c1193d4d32770 Mon Sep 17 00:00:00 2001
From: Sam M W <you@example.com>
Date: Tue, 18 Oct 2022 13:35:17 +0100
Subject: [PATCH] zeropage wraparound test

---
 src/instruction.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/instruction.rs b/src/instruction.rs
index 042c50e..d328dbf 100644
--- a/src/instruction.rs
+++ b/src/instruction.rs
@@ -768,3 +768,20 @@ pub static OPCODES: [Option<(Instruction, AddressingMode)>; 256] = [
     /*0xFF*/
     None,
 ];
+
+#[cfg(test)]
+mod tests {
+
+    #[test]
+    fn zeropage_wrap_around() {
+        use crate::instruction::AddressingMode;
+        use crate::instruction::CPU;
+        use crate::instruction::OpInput;
+
+        let mut cpu = CPU::new();
+        cpu.registers.index_x = 9;
+
+        assert!(matches!(AddressingMode::ZeroPageX.process(&cpu, &[10]), OpInput::UseAddress(19)));
+        assert!(matches!(AddressingMode::ZeroPageX.process(&cpu, &[250]), OpInput::UseAddress(3)));
+    }
+}