Improved tests

src/board/mod.rs

@@ -550,6 +550,32 @@ mod tests {
         assert_eq!(info.vid_pid(), "2341:0043");
     }
 
+    #[test]
+    fn test_vid_pid_case_insensitive() {
+        let info = PortInfo {
+            port_name: "COM3".to_string(),
+            protocol: "Serial Port (USB)".to_string(),
+            board_name: "Unknown".to_string(),
+            fqbn: String::new(),
+            vid: "0x2341".to_string(),
+            pid: "0x0043".to_string(),
+            serial_number: String::new(),
+        };
+        // vid_pid() should normalize to lowercase
+        assert_eq!(info.vid_pid(), "2341:0043");
+
+        let upper = PortInfo {
+            port_name: "COM3".to_string(),
+            protocol: "Serial Port (USB)".to_string(),
+            board_name: "Unknown".to_string(),
+            fqbn: String::new(),
+            vid: "0x1A86".to_string(),
+            pid: "0x7523".to_string(),
+            serial_number: String::new(),
+        };
+        assert_eq!(upper.vid_pid(), "1a86:7523");
+    }
+
     #[test]
     fn test_is_usb_from_vid_pid() {
         let info = PortInfo {