From 4e8ae60b3cdb7b346cc1f9034fd3eab240c98141 Mon Sep 17 00:00:00 2001
From: Denis Nutiu <denis.nutiu@gmail.com>
Date: Fri, 13 Dec 2024 15:12:29 +0200
Subject: [PATCH] add unit tests for load, store memory, bcd convert, add to
 index

---
 src/emulator.rs    | 72 ++++++++++++++++++++++++++++++++++++++++++++++
 src/instruction.rs |  4 +--
 2 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/src/emulator.rs b/src/emulator.rs
index 7af3380..94847a2 100644
--- a/src/emulator.rs
+++ b/src/emulator.rs
@@ -854,4 +854,76 @@ mod tests {
 
         assert_eq!(emulator.sound_timer, 0xEE);
     }
+
+    #[test]
+    fn test_execute_add_to_index() {
+        let mut emulator = Emulator::new(TerminalDisplay::new(), TerminalSound, NoInput);
+        emulator.registers[0xA] = 0xEE;
+
+        emulator
+            .execute_instruction(Instruction::new([0xFA, 0x1E]))
+            .expect("Failed to execute");
+
+        assert_eq!(emulator.index_register, 0xEE);
+    }
+
+    #[test]
+    fn test_execute_get_font_character() {
+        let mut emulator = Emulator::new(TerminalDisplay::new(), TerminalSound, NoInput);
+        emulator.registers[0xA] = 0xEE;
+
+        emulator
+            .execute_instruction(Instruction::new([0xFA, 0x29]))
+            .expect("Failed to execute");
+
+        assert_eq!(emulator.index_register, 0x136);
+    }
+
+    #[test]
+    fn test_execute_bcd_convert() {
+        let mut emulator = Emulator::new(TerminalDisplay::new(), TerminalSound, NoInput);
+        emulator.registers[0xA] = 0xFE;
+
+        emulator
+            .execute_instruction(Instruction::new([0xFA, 0x33]))
+            .expect("Failed to execute");
+
+        assert_eq!(emulator.memory[emulator.index_register as usize], 2);
+        assert_eq!(emulator.memory[emulator.index_register as usize + 1], 5);
+        assert_eq!(emulator.memory[emulator.index_register as usize + 2], 4);
+    }
+
+    #[test]
+    fn test_execute_store_memory() {
+        let mut emulator = Emulator::new(TerminalDisplay::new(), TerminalSound, NoInput);
+        emulator.index_register = 0x20;
+        for i in 0..0xF {
+            emulator.registers[i] = (0xF + i) as u8;
+        }
+
+        emulator
+            .execute_instruction(Instruction::new([0xFF, 0x55]))
+            .expect("Failed to execute");
+
+        for i in 0..0xF {
+            assert_eq!(emulator.memory[(emulator.index_register + i) as usize], (0xF + i) as u8);
+        }
+    }
+
+    #[test]
+    fn test_execute_load_memory() {
+        let mut emulator = Emulator::new(TerminalDisplay::new(), TerminalSound, NoInput);
+        emulator.index_register = 0x20;
+        for i in 0..0xF {
+            emulator.memory[(emulator.index_register + i) as usize] = (0xF + i) as u8;
+        }
+
+        emulator
+            .execute_instruction(Instruction::new([0xFF, 0x65]))
+            .expect("Failed to execute");
+
+        for i in 0..0xF {
+            assert_eq!(emulator.registers[i], (0xF + i) as u8);
+        }
+    }
 }
diff --git a/src/instruction.rs b/src/instruction.rs
index 4b06bd7..e573a7b 100644
--- a/src/instruction.rs
+++ b/src/instruction.rs
@@ -611,7 +611,7 @@ mod tests {
     }
 
     #[test]
-    fn test_instruction_load_memory() {
+    fn test_instruction_store_memory() {
         let instruction = Instruction::new([0xFA, 0x55]);
         assert_eq!(
             instruction.processor_instruction,
@@ -620,7 +620,7 @@ mod tests {
     }
 
     #[test]
-    fn test_instruction_store_memory() {
+    fn test_instruction_load_memory() {
         let instruction = Instruction::new([0xFA, 0x65]);
         assert_eq!(
             instruction.processor_instruction,