disallow empty messeges

src/main.rs

@@ -104,9 +104,17 @@ async fn start_client(addr: &str) -> Result<(), Box<dyn Error>> {
     loop {
         let mut input = String::new();
         reader.read_line(&mut input).await?;
-        stream.write_all(input.trim().as_bytes()).await?;
+
+        let trimmed_input = input.trim();
+
+        if trimmed_input.is_empty() {
+            println!("Empty message. Please enter a non-empty message.");
+            continue;
+        }
+
+        stream.write_all(trimmed_input.as_bytes()).await?;
 
         // Print sent message
-        println!("Sent message from {}: {}", username.trim(), input.trim());
+        println!("Sent message from {}: {}", username.trim(), trimmed_input);
     }
 }