fix(cart): rename enum variant and enable MBC3 w/ battery

src/cartridge.rs

@@ -61,8 +61,9 @@ impl Cartridge {
             MbcKind::Mbc2(hw) => Box::new(Mbc2::new(hw, rom_cap)),
             MbcKind::Mbc3(hw @ Mbc3Hardware::Rtc) => Box::new(Mbc3::new(hw, ram_cap)),
             MbcKind::Mbc3(hw @ Mbc3Hardware::RtcBatteryRam) => Box::new(Mbc3::new(hw, ram_cap)),
-            MbcKind::Mbc4(hw @ Mbc5Hardware::None) => Box::new(Mbc5::new(hw, ram_cap, rom_cap)),
-            MbcKind::Mbc4(hw @ Mbc5Hardware::BatteryRam) => {
+            MbcKind::Mbc3(hw @ Mbc3Hardware::BatteryRam) => Box::new(Mbc3::new(hw, ram_cap)),
+            MbcKind::Mbc5(hw @ Mbc5Hardware::None) => Box::new(Mbc5::new(hw, ram_cap, rom_cap)),
+            MbcKind::Mbc5(hw @ Mbc5Hardware::BatteryRam) => {
                 Box::new(Mbc5::new(hw, ram_cap, rom_cap))
             }
             kind => todo!("ROMS with {:?} are currently unsupported", kind),
@@ -70,21 +71,23 @@ impl Cartridge {
     }
 
     fn detect_title(title_mem: &[u8; ROM_TITLE_MAX_SIZE]) -> Option<String> {
+        use std::str::from_utf8;
+
         const ALT_TITLE_LEN: usize = ROM_MANUFACTURER_START - ROM_TITLE_START;
 
-        // byte slice we have here is purposely not null terminated
+        // ascii byte slie does not have a null-terminator
         let ascii = match title_mem.iter().position(|b| *b == 0x00) {
-            Some(end) => &title_mem[0..end],
-            None => &title_mem[0..ROM_TITLE_MAX_SIZE],
+            Some(end) => &title_mem[..end],
+            None => &title_mem[..ROM_TITLE_MAX_SIZE],
         };
 
-        match std::str::from_utf8(ascii).ok() {
-            None => match std::str::from_utf8(&title_mem[0..ALT_TITLE_LEN]).ok() {
+        match from_utf8(ascii).map(str::trim).ok() {
+            None => match from_utf8(&title_mem[..ALT_TITLE_LEN]).map(str::trim).ok() {
                 Some("") | None => None,
-                Some(title) => Some(String::from(title.trim())),
+                Some(title) => Some(String::from(title)),
             },
             Some("") => None,
-            Some(title) => Some(String::from(title.trim())),
+            Some(title) => Some(String::from(title)),
         }
     }
 
@@ -105,12 +108,12 @@ impl Cartridge {
             0x11 => Mbc3(Mbc3Hardware::None),
             0x12 => Mbc3(Mbc3Hardware::Ram),
             0x13 => Mbc3(Mbc3Hardware::BatteryRam),
-            0x19 => Mbc4(Mbc5Hardware::None),
-            0x1A => Mbc4(Mbc5Hardware::Ram),
-            0x1B => Mbc4(Mbc5Hardware::BatteryRam),
-            0x1C => Mbc4(Mbc5Hardware::Rumble),
-            0x1D => Mbc4(Mbc5Hardware::RumbleRam),
-            0x1E => Mbc4(Mbc5Hardware::RumbleBatteryRam),
+            0x19 => Mbc5(Mbc5Hardware::None),
+            0x1A => Mbc5(Mbc5Hardware::Ram),
+            0x1B => Mbc5(Mbc5Hardware::BatteryRam),
+            0x1C => Mbc5(Mbc5Hardware::Rumble),
+            0x1D => Mbc5(Mbc5Hardware::RumbleRam),
+            0x1E => Mbc5(Mbc5Hardware::RumbleBatteryRam),
             id => unimplemented!("MBC with code {:#04X} is unsupported", id),
         }
     }
@@ -746,7 +749,7 @@ enum MbcKind {
     Mbc1(Mbc1Hardware),
     Mbc2(Mbc2Hardware),
     Mbc3(Mbc3Hardware),
-    Mbc4(Mbc5Hardware),
+    Mbc5(Mbc5Hardware),
 }
 
 #[derive(Debug, Clone, Copy)]
@@ -950,4 +953,14 @@ mod tests {
             Cartridge::detect_title(&title)
         );
     }
+
+    #[test]
+    fn all_whitespace_title() {
+        let title = [
+            0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+            0x00, 0x00,
+        ];
+
+        assert_eq!(None, Cartridge::detect_title(&title));
+    }
 }