don't error on dropped connections

src/main.rs

@@ -21,7 +21,7 @@ use tokio::{
     sync::Mutex,
     time::sleep,
 };
-use tracing::{error, info, instrument, warn, Level};
+use tracing::{debug, error, info, instrument, warn, Level};
 use tracing_subscriber::fmt::time::FormatTime;
 
 use crate::packets::PacketKind;
@@ -247,7 +247,14 @@ async fn connection_handler(
 
     let error = match res {
         Err(_) => Some("internal server error".to_owned()),
-        Ok(Err(err)) => Some(err.to_string()),
+        Ok(Err(err)) => match err.downcast_ref::<std::io::Error>() {
+            Some(io_error) if io_error.kind() == std::io::ErrorKind::UnexpectedEof => {
+                debug!(%addr, "Client dropped their connection");
+                // don't print an error on dropped connections
+                None
+            }
+            _ => Some(err.to_string()),
+        },
         Ok(Ok(())) => None,
     };
 
@@ -264,6 +271,7 @@ async fn connection_handler(
             length: packet.data.len().try_into().unwrap(), // this will never fail, as we just truncated the vector
         };
 
+        // Attempt to notify the client of the failure
         let (_, mut writer) = stream.split();
         _ = packet.send(&mut writer).await;
     }