chore: handle all cases for EventMsg (#936)

For now, this removes the `#[non_exhaustive]` directive on `EventMsg` so
that we are forced to handle all `EventMsg` by default. (We may revisit
this if/when we publish `core/` as a `lib` crate.) For now, it is
helpful to have this as a forcing function because we have effectively
two UIs (`tui` and `exec`) and usually when we add a new variant to
`EventMsg`, we want to be sure that we update both.

codex-rs/core/src/protocol.rs

@@ -298,7 +298,6 @@ pub struct Event {
 }
 
 /// Response event from the agent
-#[non_exhaustive]
 #[derive(Debug, Clone, Deserialize, Serialize)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum EventMsg {

codex-rs/core/tests/live_agent.rs

@@ -99,7 +99,9 @@ async fn live_streaming_and_prev_id_reset() {
             EventMsg::Error(ErrorEvent { message }) => {
                 panic!("agent reported error in task1: {message}")
             }
-            _ => (),
+            _ => {
+                // Ignore other events.
+            }
         }
     }
 
@@ -135,7 +137,9 @@ async fn live_streaming_and_prev_id_reset() {
             EventMsg::Error(ErrorEvent { message }) => {
                 panic!("agent reported error in task2: {message}")
             }
-            _ => (),
+            _ => {
+                // Ignore other events.
+            }
         }
     }
 
@@ -201,7 +205,9 @@ async fn live_shell_function_call() {
             EventMsg::Error(codex_core::protocol::ErrorEvent { message }) => {
                 panic!("agent error during shell test: {message}")
             }
-            _ => (),
+            _ => {
+                // Ignore other events.
+            }
         }
     }
 

codex-rs/core/tests/previous_response_id.rs

@@ -155,7 +155,9 @@ async fn keeps_previous_response_id_between_tasks() {
             EventMsg::Error(ErrorEvent { message }) => {
                 panic!("unexpected error: {message}")
             }
-            _ => (),
+            _ => {
+                // Ignore other events.
+            }
         }
     }
 }