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.

Author: bolinfest

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.
+            }
         }
     }
 }

codex-rs/exec/src/event_processor.rs

@@ -12,6 +12,7 @@ use codex_core::protocol::McpToolCallBeginEvent;
 use codex_core::protocol::McpToolCallEndEvent;
 use codex_core::protocol::PatchApplyBeginEvent;
 use codex_core::protocol::PatchApplyEndEvent;
+use codex_core::protocol::SessionConfiguredEvent;
 use owo_colors::OwoColorize;
 use owo_colors::Style;
 use shlex::try_join;
@@ -180,8 +181,6 @@ impl EventProcessor {
                 }
                 println!("{}", truncated_output.style(self.dimmed));
             }
-
-            // Handle MCP tool calls (e.g. calling external functions via MCP).
             EventMsg::McpToolCallBegin(McpToolCallBeginEvent {
                 call_id,
                 server,
@@ -372,8 +371,12 @@ impl EventProcessor {
             EventMsg::ApplyPatchApprovalRequest(_) => {
                 // Should we exit?
             }
-            _ => {
-                // Ignore event.
+            EventMsg::AgentReasoning(agent_reasoning_event) => {
+                println!("thinking: {}", agent_reasoning_event.text);
+            }
+            EventMsg::SessionConfigured(session_configured_event) => {
+                let SessionConfiguredEvent { session_id, model } = session_configured_event;
+                println!("session {session_id} with model {model}");
             }
         }
     }

codex-rs/mcp-server/src/codex_tool_runner.rs

@@ -157,7 +157,23 @@ pub async fn run_codex_tool_session(
                     EventMsg::SessionConfigured(_) => {
                         tracing::error!("unexpected SessionConfigured event");
                     }
-                    _ => {}
+                    EventMsg::Error(_)
+                    | EventMsg::TaskStarted
+                    | EventMsg::AgentReasoning(_)
+                    | EventMsg::McpToolCallBegin(_)
+                    | EventMsg::McpToolCallEnd(_)
+                    | EventMsg::ExecCommandBegin(_)
+                    | EventMsg::ExecCommandEnd(_)
+                    | EventMsg::BackgroundEvent(_)
+                    | EventMsg::PatchApplyBegin(_)
+                    | EventMsg::PatchApplyEnd(_) => {
+                        // For now, we do not do anything extra for these
+                        // events. Note that
+                        // send(codex_event_to_notification(&event)) above has
+                        // already dispatched these events as notifications,
+                        // though we may want to do give different treatment to
+                        // individual events in the future.
+                    }
                 }
             }
             Err(e) => {