Make AgentError implement std::error::Error

Signed-off-by: Wiktor Kwapisiewicz <[email protected]>

src/error.rs

@@ -19,3 +19,15 @@ impl From<io::Error> for AgentError {
         AgentError::IO(e)
     }
 }
+
+impl std::fmt::Display for AgentError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            AgentError::User => write!(f, "Agent: User error"),
+            AgentError::Proto(proto) => write!(f, "Agent: Protocol error: {}", proto),
+            AgentError::IO(error) => write!(f, "Agent: I/O error: {}", error),
+        }
+    }
+}
+
+impl std::error::Error for AgentError {}