Implement request response messaging

nats-client/src/chat_message.rs

@@ -26,6 +26,13 @@ impl TryFrom<Vec<u8>> for ChatMessage {
     }
 }
 
+impl From<ChatMessage> for Vec<u8> {
+    fn from(value: ChatMessage) -> Self {
+        let json_string_utf8 = serde_json::to_string(&value).expect("Cannot serialize message");
+        json_string_utf8.into_bytes()
+    }
+}
+
 #[derive(Debug)]
 pub enum NatsParsingError {
     // Message was no string at all
@@ -41,7 +48,7 @@ impl Display for NatsParsingError {
         let message = match self {
             NatsParsingError::NoValidUtf8 => "NATS message was no valid UTF-8 string.",
             NatsParsingError::CannotDeserializeJson => {
-                "NATS message is not a valid / expected json."
+                "NATS message is not a json of expected structure."
             }
         };
         writeln!(f, "{}", message)