rust-protocol: Implement a simple unit test.

common/rust-protocol/src/lib.rs

 //! base station and all sensor/display nodes.
 #![no_std]
 
+#[cfg(test)]
+extern crate std;
+
 use core::convert::TryInto;
 
 use crc16::{State, KERMIT};
 use xxtea_nostd::{decrypt, encrypt};
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Packet {
     GetSalt,
     Salt(u64),
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Report {
     pub count: u8,
     pub values: [Value; 8],
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct GetValues {
     pub count: u8,
     pub location: Location,
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Values {
     pub count: u8,
     pub location: Location,
     }
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub enum Location {
     Livingroom,
     Bathroom,
     Balcony,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub enum Value {
     Invalid,
     Time(u64),
     }
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub enum ValueType {
     Time,
     Temperature,
     InvalidLocation,
     TooShort,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::println;
+
+    #[test]
+    fn test_identity() {
+        let packets = [Packet::GetSalt, Packet::Salt(0x12345678abcdef12)];
+
+        let key = [
+            0x12, 0x34, 0x56, 0x78, 0xab, 0xcd, 0xef, 0x12, 0x12, 0x34, 0x56, 0x78, 0xab, 0xcd,
+            0xef, 0x12,
+        ];
+
+        for packet in packets.iter() {
+            let mut encoded = [0u8; 32];
+            packet.encode_and_encrypt(&key, 0x1234123412341234, &mut encoded);
+            assert_eq!(encoded[0], 0x34);
+            assert_eq!(encoded[7], 0x12);
+            let decoded = Packet::decrypt_and_decode(&key, &mut encoded).unwrap();
+            // TODO: Compare encoded and decoded.
+        }
+    }
+}