Clean up code

nats-client/src/chat_message.rs

@@ -0,0 +1,49 @@
+use core::fmt;
+use std::{error::Error, fmt::Display};
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+pub struct ChatMessage {
+    pub author: String,
+    pub message: String,
+}
+
+impl Display for ChatMessage {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Message from {}: {}", self.author, self.message)
+    }
+}
+
+impl TryFrom<Vec<u8>> for ChatMessage {
+    type Error = NatsParsingError;
+
+    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
+        let as_string = &String::from_utf8(value).map_err(|_| NatsParsingError::NoValidUtf8)?;
+        let to_return =
+            serde_json::from_str(as_string).map_err(|_| NatsParsingError::CannotDeserializeJson)?;
+        Ok(to_return)
+    }
+}
+
+#[derive(Debug)]
+pub enum NatsParsingError {
+    // Message was no string at all
+    NoValidUtf8,
+    // Message could be invalid json or json not matching the struct you want to deserialize
+    CannotDeserializeJson,
+}
+
+impl Error for NatsParsingError {}
+
+impl Display for NatsParsingError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let message = match self {
+            NatsParsingError::NoValidUtf8 => "NATS message was no valid UTF-8 string.",
+            NatsParsingError::CannotDeserializeJson => {
+                "NATS message is not a valid / expected json."
+            }
+        };
+        writeln!(f, "{}", message)
+    }
+}