Add msg! helper macro for generating types impl Encode

Author: robertwayne

rust/bufferfish/src/lib.rs

@@ -7,6 +7,41 @@ pub use bufferfish_derive::{Decode, Encode};
 #[cfg(feature = "derive")]
 pub use compiler::generate;
 
+/// Helper macro for defining packets with reduced boilerplate.
+///
+/// # Examples
+///
+/// ```rust
+/// # use bufferfish::packet;
+/// # enum ClientEventId { HeartbeatAck, ChatMessage }
+/// // Empty packet
+/// packet!(HeartbeatAckPacket, ClientEventId::HeartbeatAck);
+///
+/// // Packet with fields
+/// packet!(SendChatMessagePacket, ClientEventId::ChatMessage, {
+///     pub content: String,
+/// });
+/// ```
+#[cfg(feature = "derive")]
+#[macro_export]
+macro_rules! msg {
+    // Empty message
+    ($name:ident, $id:expr) => {
+        #[derive(Debug, Encode)]
+        #[bufferfish($id)]
+        pub struct $name;
+    };
+
+    // Message with fields
+    ($name:ident, $id:expr, { $($field:vis $field_name:ident: $field_type:ty),* $(,)? }) => {
+        #[derive(Debug, Encode)]
+        #[bufferfish($id)]
+        pub struct $name {
+            $($field $field_name: $field_type,)*
+        }
+    };
+}
+
 #[cfg(feature = "derive")]
 #[cfg(test)]
 mod tests {
@@ -342,16 +377,6 @@ mod tests {
         assert_eq!(bf.read_i128().unwrap(), i128::MIN);
     }
 
-    #[test]
-    fn test_read_reset() {
-        let mut bf = Bufferfish::new();
-        bf.write_u8(0).unwrap();
-        bf.read_u8().unwrap();
-        bf.write_u8(255).unwrap();
-
-        assert_eq!(bf.read_u8().unwrap(), 0);
-    }
-
     #[test]
     fn test_bufferfish_overflow() {
         let mut bf = Bufferfish::new();
@@ -1021,6 +1046,6 @@ mod tests {
         bf.reset();
 
         assert_eq!(bf.len(), 0);
-        assert_eq!(bf.as_ref(), &[]);
+        assert_eq!(bf.as_ref(), &[] as &[u8]);
     }
 }