Use Shift+Left to edit queued messages in tmux (#15480)

## Summary
- use Shift+Left to edit the most recent queued message when running
under tmux
- mirror the same binding change in the app-server TUI
- add tmux-specific tests and snapshot coverage for the rendered
queued-message hint

## Testing
- just fmt
- cargo test -p codex-tui
- cargo test -p codex-tui-app-server
- just argument-comment-lint -p codex-tui -p codex-tui-app-server

Co-authored-by: Codex <noreply@openai.com>

codex-rs/tui/src/bottom_pane/pending_input_preview.rs

@@ -176,6 +176,21 @@ mod tests {
         assert_snapshot!("render_one_message", format!("{buf:?}"));
     }
 
+    #[test]
+    fn render_one_message_with_shift_left_binding() {
+        let mut queue = PendingInputPreview::new();
+        queue.queued_messages.push("Hello, world!".to_string());
+        queue.set_edit_binding(key_hint::shift(KeyCode::Left));
+        let width = 40;
+        let height = queue.desired_height(width);
+        let mut buf = Buffer::empty(Rect::new(0, 0, width, height));
+        queue.render(Rect::new(0, 0, width, height), &mut buf);
+        assert_snapshot!(
+            "render_one_message_with_shift_left_binding",
+            format!("{buf:?}")
+        );
+    }
+
     #[test]
     fn render_two_messages() {
         let mut queue = PendingInputPreview::new();

codex-rs/tui/src/bottom_pane/snapshots/codex_tui__bottom_pane__pending_input_preview__tests__render_one_message_with_shift_left_binding.snap

@@ -0,0 +1,21 @@
+---
+source: tui/src/bottom_pane/pending_input_preview.rs
+expression: "format!(\"{buf:?}\")"
+---
+Buffer {
+    area: Rect { x: 0, y: 0, width: 40, height: 3 },
+    content: [
+        "• Queued follow-up messages             ",
+        "  ↳ Hello, world!                       ",
+        "    shift + ← edit last queued message  ",
+    ],
+    styles: [
+        x: 0, y: 0, fg: Reset, bg: Reset, underline: Reset, modifier: DIM,
+        x: 2, y: 0, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
+        x: 0, y: 1, fg: Reset, bg: Reset, underline: Reset, modifier: DIM,
+        x: 4, y: 1, fg: Reset, bg: Reset, underline: Reset, modifier: DIM | ITALIC,
+        x: 17, y: 1, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
+        x: 0, y: 2, fg: Reset, bg: Reset, underline: Reset, modifier: DIM,
+        x: 38, y: 2, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
+    ]
+}

codex-rs/tui/src/chatwidget.rs

@@ -155,6 +155,8 @@ use codex_protocol::request_permissions::RequestPermissionsEvent;
 use codex_protocol::request_user_input::RequestUserInputEvent;
 use codex_protocol::user_input::TextElement;
 use codex_protocol::user_input::UserInput;
+use codex_terminal_detection::Multiplexer;
+use codex_terminal_detection::TerminalInfo;
 use codex_terminal_detection::TerminalName;
 use codex_terminal_detection::terminal_info;
 use codex_utils_sleep_inhibitor::SleepInhibitor;
@@ -195,14 +197,21 @@ const CONNECTORS_SELECTION_VIEW_ID: &str = "connectors-selection";
 /// Choose the keybinding used to edit the most-recently queued message.
 ///
 /// Apple Terminal, Warp, and VSCode integrated terminals intercept or silently
-/// swallow Alt+Up, so users in those environments would never be able to trigger
-/// the edit action.  We fall back to Shift+Left for those terminals while
-/// keeping the more discoverable Alt+Up everywhere else.
+/// swallow Alt+Up, and tmux does not reliably pass that chord through. We fall
+/// back to Shift+Left for those environments while keeping the more discoverable
+/// Alt+Up everywhere else.
 ///
 /// The match is exhaustive so that adding a new `TerminalName` variant forces
 /// an explicit decision about which binding that terminal should use.
-fn queued_message_edit_binding_for_terminal(terminal_name: TerminalName) -> KeyBinding {
-    match terminal_name {
+fn queued_message_edit_binding_for_terminal(terminal_info: TerminalInfo) -> KeyBinding {
+    if matches!(
+        terminal_info.multiplexer.as_ref(),
+        Some(Multiplexer::Tmux { .. })
+    ) {
+        return key_hint::shift(KeyCode::Left);
+    }
+
+    match terminal_info.name {
         TerminalName::AppleTerminal | TerminalName::WarpTerminal | TerminalName::VsCode => {
             key_hint::shift(KeyCode::Left)
         }
@@ -3617,8 +3626,7 @@ impl ChatWidget {
         let active_cell = Some(Self::placeholder_session_header_cell(&config));
 
         let current_cwd = Some(config.cwd.clone());
-        let queued_message_edit_binding =
-            queued_message_edit_binding_for_terminal(terminal_info().name);
+        let queued_message_edit_binding = queued_message_edit_binding_for_terminal(terminal_info());
         let mut widget = Self {
             app_event_tx: app_event_tx.clone(),
             frame_requester: frame_requester.clone(),
@@ -3819,8 +3827,7 @@ impl ChatWidget {
         let active_cell = Some(Self::placeholder_session_header_cell(&config));
         let current_cwd = Some(config.cwd.clone());
 
-        let queued_message_edit_binding =
-            queued_message_edit_binding_for_terminal(terminal_info().name);
+        let queued_message_edit_binding = queued_message_edit_binding_for_terminal(terminal_info());
         let mut widget = Self {
             app_event_tx: app_event_tx.clone(),
             frame_requester: frame_requester.clone(),
@@ -4013,8 +4020,7 @@ impl ChatWidget {
             settings: fallback_default,
         };
 
-        let queued_message_edit_binding =
-            queued_message_edit_binding_for_terminal(terminal_info().name);
+        let queued_message_edit_binding = queued_message_edit_binding_for_terminal(terminal_info());
         let mut widget = Self {
             app_event_tx: app_event_tx.clone(),
             frame_requester: frame_requester.clone(),

codex-rs/tui/src/chatwidget/tests.rs

@@ -120,6 +120,8 @@ use codex_protocol::request_user_input::RequestUserInputQuestion;
 use codex_protocol::request_user_input::RequestUserInputQuestionOption;
 use codex_protocol::user_input::TextElement;
 use codex_protocol::user_input::UserInput;
+use codex_terminal_detection::Multiplexer;
+use codex_terminal_detection::TerminalInfo;
 use codex_terminal_detection::TerminalName;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_approval_presets::builtin_approval_presets;
@@ -3756,10 +3758,10 @@ async fn alt_up_edits_most_recent_queued_message() {
 }
 
 async fn assert_shift_left_edits_most_recent_queued_message_for_terminal(
-    terminal_name: TerminalName,
+    terminal_info: TerminalInfo,
 ) {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual(None).await;
-    chat.queued_message_edit_binding = queued_message_edit_binding_for_terminal(terminal_name);
+    chat.queued_message_edit_binding = queued_message_edit_binding_for_terminal(terminal_info);
     chat.bottom_pane
         .set_queued_message_edit_binding(chat.queued_message_edit_binding);
 
@@ -3791,37 +3793,102 @@ async fn assert_shift_left_edits_most_recent_queued_message_for_terminal(
 
 #[tokio::test]
 async fn shift_left_edits_most_recent_queued_message_in_apple_terminal() {
-    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalName::AppleTerminal)
-        .await;
+    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalInfo {
+        name: TerminalName::AppleTerminal,
+        term_program: None,
+        version: None,
+        term: None,
+        multiplexer: None,
+    })
+    .await;
 }
 
 #[tokio::test]
 async fn shift_left_edits_most_recent_queued_message_in_warp_terminal() {
-    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalName::WarpTerminal)
-        .await;
+    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalInfo {
+        name: TerminalName::WarpTerminal,
+        term_program: None,
+        version: None,
+        term: None,
+        multiplexer: None,
+    })
+    .await;
 }
 
 #[tokio::test]
 async fn shift_left_edits_most_recent_queued_message_in_vscode_terminal() {
-    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalName::VsCode).await;
+    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalInfo {
+        name: TerminalName::VsCode,
+        term_program: None,
+        version: None,
+        term: None,
+        multiplexer: None,
+    })
+    .await;
+}
+
+#[tokio::test]
+async fn shift_left_edits_most_recent_queued_message_in_tmux() {
+    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalInfo {
+        name: TerminalName::Iterm2,
+        term_program: None,
+        version: None,
+        term: None,
+        multiplexer: Some(Multiplexer::Tmux { version: None }),
+    })
+    .await;
 }
 
 #[test]
-fn queued_message_edit_binding_mapping_covers_special_terminals() {
+fn queued_message_edit_binding_mapping_covers_special_terminals_and_tmux() {
     assert_eq!(
-        queued_message_edit_binding_for_terminal(TerminalName::AppleTerminal),
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::AppleTerminal,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: None,
+        }),
         crate::key_hint::shift(KeyCode::Left)
     );
     assert_eq!(
-        queued_message_edit_binding_for_terminal(TerminalName::WarpTerminal),
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::WarpTerminal,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: None,
+        }),
         crate::key_hint::shift(KeyCode::Left)
     );
     assert_eq!(
-        queued_message_edit_binding_for_terminal(TerminalName::VsCode),
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::VsCode,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: None,
+        }),
         crate::key_hint::shift(KeyCode::Left)
     );
     assert_eq!(
-        queued_message_edit_binding_for_terminal(TerminalName::Iterm2),
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::Iterm2,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: Some(Multiplexer::Tmux { version: None }),
+        }),
+        crate::key_hint::shift(KeyCode::Left)
+    );
+    assert_eq!(
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::Iterm2,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: None,
+        }),
         crate::key_hint::alt(KeyCode::Up)
     );
 }

codex-rs/tui_app_server/src/bottom_pane/pending_input_preview.rs

@@ -176,6 +176,21 @@ mod tests {
         assert_snapshot!("render_one_message", format!("{buf:?}"));
     }
 
+    #[test]
+    fn render_one_message_with_shift_left_binding() {
+        let mut queue = PendingInputPreview::new();
+        queue.queued_messages.push("Hello, world!".to_string());
+        queue.set_edit_binding(key_hint::shift(KeyCode::Left));
+        let width = 40;
+        let height = queue.desired_height(width);
+        let mut buf = Buffer::empty(Rect::new(0, 0, width, height));
+        queue.render(Rect::new(0, 0, width, height), &mut buf);
+        assert_snapshot!(
+            "render_one_message_with_shift_left_binding",
+            format!("{buf:?}")
+        );
+    }
+
     #[test]
     fn render_two_messages() {
         let mut queue = PendingInputPreview::new();

codex-rs/tui_app_server/src/bottom_pane/snapshots/codex_tui_app_server__bottom_pane__pending_input_preview__tests__render_one_message_with_shift_left_binding.snap

@@ -0,0 +1,21 @@
+---
+source: tui_app_server/src/bottom_pane/pending_input_preview.rs
+expression: "format!(\"{buf:?}\")"
+---
+Buffer {
+    area: Rect { x: 0, y: 0, width: 40, height: 3 },
+    content: [
+        "• Queued follow-up messages             ",
+        "  ↳ Hello, world!                       ",
+        "    shift + ← edit last queued message  ",
+    ],
+    styles: [
+        x: 0, y: 0, fg: Reset, bg: Reset, underline: Reset, modifier: DIM,
+        x: 2, y: 0, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
+        x: 0, y: 1, fg: Reset, bg: Reset, underline: Reset, modifier: DIM,
+        x: 4, y: 1, fg: Reset, bg: Reset, underline: Reset, modifier: DIM | ITALIC,
+        x: 17, y: 1, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
+        x: 0, y: 2, fg: Reset, bg: Reset, underline: Reset, modifier: DIM,
+        x: 38, y: 2, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
+    ]
+}

codex-rs/tui_app_server/src/chatwidget.rs

@@ -199,6 +199,8 @@ use codex_protocol::request_user_input::RequestUserInputEvent;
 use codex_protocol::request_user_input::RequestUserInputQuestionOption;
 use codex_protocol::user_input::TextElement;
 use codex_protocol::user_input::UserInput;
+use codex_terminal_detection::Multiplexer;
+use codex_terminal_detection::TerminalInfo;
 use codex_terminal_detection::TerminalName;
 use codex_terminal_detection::terminal_info;
 use codex_utils_sleep_inhibitor::SleepInhibitor;
@@ -238,14 +240,21 @@ const APP_SERVER_TUI_STUB_MESSAGE: &str = "Not available in app-server TUI yet."
 /// Choose the keybinding used to edit the most-recently queued message.
 ///
 /// Apple Terminal, Warp, and VSCode integrated terminals intercept or silently
-/// swallow Alt+Up, so users in those environments would never be able to trigger
-/// the edit action.  We fall back to Shift+Left for those terminals while
-/// keeping the more discoverable Alt+Up everywhere else.
+/// swallow Alt+Up, and tmux does not reliably pass that chord through. We fall
+/// back to Shift+Left for those environments while keeping the more discoverable
+/// Alt+Up everywhere else.
 ///
 /// The match is exhaustive so that adding a new `TerminalName` variant forces
 /// an explicit decision about which binding that terminal should use.
-fn queued_message_edit_binding_for_terminal(terminal_name: TerminalName) -> KeyBinding {
-    match terminal_name {
+fn queued_message_edit_binding_for_terminal(terminal_info: TerminalInfo) -> KeyBinding {
+    if matches!(
+        terminal_info.multiplexer.as_ref(),
+        Some(Multiplexer::Tmux { .. })
+    ) {
+        return key_hint::shift(KeyCode::Left);
+    }
+
+    match terminal_info.name {
         TerminalName::AppleTerminal | TerminalName::WarpTerminal | TerminalName::VsCode => {
             key_hint::shift(KeyCode::Left)
         }
@@ -4170,8 +4179,7 @@ impl ChatWidget {
         let active_cell = Some(Self::placeholder_session_header_cell(&config));
 
         let current_cwd = Some(config.cwd.clone());
-        let queued_message_edit_binding =
-            queued_message_edit_binding_for_terminal(terminal_info().name);
+        let queued_message_edit_binding = queued_message_edit_binding_for_terminal(terminal_info());
         let mut widget = Self {
             app_event_tx: app_event_tx.clone(),
             frame_requester: frame_requester.clone(),

codex-rs/tui_app_server/src/chatwidget/tests.rs

@@ -143,6 +143,8 @@ use codex_protocol::request_user_input::RequestUserInputQuestion;
 use codex_protocol::request_user_input::RequestUserInputQuestionOption;
 use codex_protocol::user_input::TextElement;
 use codex_protocol::user_input::UserInput;
+use codex_terminal_detection::Multiplexer;
+use codex_terminal_detection::TerminalInfo;
 use codex_terminal_detection::TerminalName;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_approval_presets::builtin_approval_presets;
@@ -3765,10 +3767,10 @@ async fn alt_up_edits_most_recent_queued_message() {
 }
 
 async fn assert_shift_left_edits_most_recent_queued_message_for_terminal(
-    terminal_name: TerminalName,
+    terminal_info: TerminalInfo,
 ) {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual(None).await;
-    chat.queued_message_edit_binding = queued_message_edit_binding_for_terminal(terminal_name);
+    chat.queued_message_edit_binding = queued_message_edit_binding_for_terminal(terminal_info);
     chat.bottom_pane
         .set_queued_message_edit_binding(chat.queued_message_edit_binding);
 
@@ -3800,37 +3802,102 @@ async fn assert_shift_left_edits_most_recent_queued_message_for_terminal(
 
 #[tokio::test]
 async fn shift_left_edits_most_recent_queued_message_in_apple_terminal() {
-    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalName::AppleTerminal)
-        .await;
+    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalInfo {
+        name: TerminalName::AppleTerminal,
+        term_program: None,
+        version: None,
+        term: None,
+        multiplexer: None,
+    })
+    .await;
 }
 
 #[tokio::test]
 async fn shift_left_edits_most_recent_queued_message_in_warp_terminal() {
-    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalName::WarpTerminal)
-        .await;
+    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalInfo {
+        name: TerminalName::WarpTerminal,
+        term_program: None,
+        version: None,
+        term: None,
+        multiplexer: None,
+    })
+    .await;
 }
 
 #[tokio::test]
 async fn shift_left_edits_most_recent_queued_message_in_vscode_terminal() {
-    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalName::VsCode).await;
+    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalInfo {
+        name: TerminalName::VsCode,
+        term_program: None,
+        version: None,
+        term: None,
+        multiplexer: None,
+    })
+    .await;
+}
+
+#[tokio::test]
+async fn shift_left_edits_most_recent_queued_message_in_tmux() {
+    assert_shift_left_edits_most_recent_queued_message_for_terminal(TerminalInfo {
+        name: TerminalName::Iterm2,
+        term_program: None,
+        version: None,
+        term: None,
+        multiplexer: Some(Multiplexer::Tmux { version: None }),
+    })
+    .await;
 }
 
 #[test]
-fn queued_message_edit_binding_mapping_covers_special_terminals() {
+fn queued_message_edit_binding_mapping_covers_special_terminals_and_tmux() {
     assert_eq!(
-        queued_message_edit_binding_for_terminal(TerminalName::AppleTerminal),
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::AppleTerminal,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: None,
+        }),
         crate::key_hint::shift(KeyCode::Left)
     );
     assert_eq!(
-        queued_message_edit_binding_for_terminal(TerminalName::WarpTerminal),
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::WarpTerminal,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: None,
+        }),
         crate::key_hint::shift(KeyCode::Left)
     );
     assert_eq!(
-        queued_message_edit_binding_for_terminal(TerminalName::VsCode),
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::VsCode,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: None,
+        }),
         crate::key_hint::shift(KeyCode::Left)
     );
     assert_eq!(
-        queued_message_edit_binding_for_terminal(TerminalName::Iterm2),
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::Iterm2,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: Some(Multiplexer::Tmux { version: None }),
+        }),
+        crate::key_hint::shift(KeyCode::Left)
+    );
+    assert_eq!(
+        queued_message_edit_binding_for_terminal(TerminalInfo {
+            name: TerminalName::Iterm2,
+            term_program: None,
+            version: None,
+            term: None,
+            multiplexer: None,
+        }),
         crate::key_hint::alt(KeyCode::Up)
     );
 }