test: add proto and end-to-end transfer tests

crates/pfs-tftp-proto/src/packet.rs

@@ -363,8 +363,31 @@ mod tests {
     #[test]
     fn rejects_data_larger_than_512() {
         let mut bytes = vec![0, 3, 0, 1];
-        bytes.extend(std::iter::repeat(0x61).take(BLOCK_SIZE + 1));
+        bytes.extend(std::iter::repeat_n(0x61, BLOCK_SIZE + 1));
         let err = Packet::decode(&bytes).unwrap_err();
         assert!(matches!(err, DecodeError::OversizeData(513)));
     }
+
+    #[allow(clippy::unwrap_used)]
+    #[test]
+    fn mode_is_case_insensitive() {
+        let req = Packet::decode(b"\0\x01file\0NeTaScIi\0").unwrap();
+        assert!(matches!(
+            req,
+            Packet::Rrq(Request {
+                mode: Mode::NetAscii,
+                ..
+            })
+        ));
+    }
+
+    #[allow(clippy::unwrap_used)]
+    #[test]
+    fn error_roundtrip() {
+        let pkt = Packet::Error {
+            code: ErrorCode::AccessViolation,
+            message: "nope".to_string(),
+        };
+        assert_eq!(Packet::decode(&pkt.encode()).unwrap(), pkt);
+    }
 }