feat(tui): right arrow accepts the typeahead suggestion at end of input (#157)

Fish-style acceptance: a configurable 'right' -> moveRight binding in the Chat context routes through the keybinding system; the handler accepts the current suggestion when the cursor sits at the end of the input and moves the cursor otherwise. Tab acceptance now also works while a turn is streaming, so the popup stays interactive and Enter queues the completed command.

Author: BunsDev

src-rust/crates/core/src/keybindings.rs

@@ -212,6 +212,7 @@ pub const NON_REBINDABLE: &[&str] = &["ctrl+c", "ctrl+d", "ctrl+m"];
 /// - **Ctrl+K**: Open the command palette
 /// - **Ctrl+U**: Kill input from cursor to start of line (Emacs-style)
 /// - **Alt+←/Alt+→**: Navigate to previous/next message in transcript
+/// - **→ (Right)**: Accept typeahead suggestion when the cursor is at the end of the input
 /// - **Ctrl+. (Ctrl+>)**: Jump to next error/issue in messages
 /// - **Ctrl+Shift+.**: Jump to previous error/issue
 /// - **Shift+Tab**: Reverse indent/unindent in input (cycle permission mode)
@@ -255,6 +256,9 @@ pub fn default_bindings() -> Vec<ParsedBinding> {
         // Word navigation
         ("ctrl+left", "moveWordBackward", KeyContext::Chat),
         ("ctrl+right", "moveWordForward", KeyContext::Chat),
+        // Cursor movement / typeahead acceptance (fish-style: right arrow at
+        // the end of the input accepts the current suggestion)
+        ("right", "moveRight", KeyContext::Chat),
         // Word deletion
         ("ctrl+w", "killWord", KeyContext::Chat),
         ("alt+backspace", "killWord", KeyContext::Chat),
@@ -996,4 +1000,26 @@ mod tests {
             other => panic!("Expected Action(\"goLineStart\"), got {:?}", other),
         }
     }
+
+    #[test]
+    fn test_right_resolves_to_move_right_in_chat() {
+        let user = UserKeybindings::default();
+        let mut resolver = KeybindingResolver::new(&user);
+
+        let keystroke = ParsedKeystroke {
+            key: "right".to_string(),
+            ctrl: false,
+            alt: false,
+            shift: false,
+            meta: false,
+        };
+
+        let result = resolver.process(keystroke, &KeyContext::Chat);
+        match result {
+            KeybindingResult::Action(action) => {
+                assert_eq!(action, "moveRight", "Right should map to moveRight");
+            }
+            other => panic!("Expected Action(\"moveRight\"), got {:?}", other),
+        }
+    }
 }

src-rust/crates/tui/src/app.rs

@@ -5477,6 +5477,26 @@ impl App {
                 }
                 false
             }
+            "moveRight" => {
+                // Right arrow: accept the typeahead suggestion when the
+                // cursor sits at the end of the input (fish-style);
+                // otherwise move the cursor. Acceptance works while
+                // streaming so the popup stays interactive when a turn is
+                // in flight — Enter then queues the completed command.
+                if !self.prompt_input.suggestions.is_empty()
+                    && self.prompt_input.cursor == self.prompt_input.text.len()
+                {
+                    if self.prompt_input.suggestion_index.is_none() {
+                        self.prompt_input.suggestion_index = Some(0);
+                    }
+                    self.prompt_input.accept_suggestion();
+                    self.refresh_prompt_input();
+                } else {
+                    self.prompt_input.move_right();
+                    self.sync_legacy_prompt_fields();
+                }
+                false
+            }
             "killToStart" => {
                 if !self.is_streaming {
                     self.prompt_input.kill_line_backward();
@@ -5652,19 +5672,19 @@ impl App {
                 false
             }
             "indent" => {
-                // Tab: cycle agent mode when prompt is empty, accept
-                // slash-command suggestion otherwise.
-                if !self.is_streaming {
-                    if !self.prompt_input.suggestions.is_empty() {
-                        if self.prompt_input.suggestion_index.is_none() {
-                            self.prompt_input.suggestion_index = Some(0);
-                        }
-                        self.prompt_input.accept_suggestion();
-                        self.refresh_prompt_input();
-                    } else if self.prompt_input.is_empty() {
-                        self.cycle_agent_mode();
-                        self.companion_look_down();
+                // Tab: accept the typeahead suggestion, or cycle agent mode
+                // when the prompt is empty. Acceptance is allowed while
+                // streaming so the popup stays interactive when a turn is
+                // in flight — Enter then queues the completed command.
+                if !self.prompt_input.suggestions.is_empty() {
+                    if self.prompt_input.suggestion_index.is_none() {
+                        self.prompt_input.suggestion_index = Some(0);
                     }
+                    self.prompt_input.accept_suggestion();
+                    self.refresh_prompt_input();
+                } else if !self.is_streaming && self.prompt_input.is_empty() {
+                    self.cycle_agent_mode();
+                    self.companion_look_down();
                 }
                 false
             }
@@ -8041,6 +8061,57 @@ role = "Research"
         assert!(app.has_credentials);
     }
 
+    #[test]
+    fn right_arrow_at_end_accepts_typeahead_suggestion() {
+        let mut app = make_app();
+        app.prompt_input.text = "/mode".to_string();
+        app.prompt_input.cursor = app.prompt_input.text.len();
+        app.refresh_prompt_input();
+        assert!(
+            !app.prompt_input.suggestions.is_empty(),
+            "typing /mode must surface the /model suggestion"
+        );
+
+        app.handle_keybinding_action("moveRight");
+
+        assert_eq!(app.prompt_input.text, "/model");
+        assert_eq!(app.prompt_input.cursor, app.prompt_input.text.len());
+    }
+
+    #[test]
+    fn right_arrow_mid_text_moves_cursor_without_accepting() {
+        let mut app = make_app();
+        app.prompt_input.text = "/mode".to_string();
+        app.prompt_input.cursor = 1;
+        app.refresh_prompt_input();
+        assert!(!app.prompt_input.suggestions.is_empty());
+
+        app.handle_keybinding_action("moveRight");
+
+        assert_eq!(
+            app.prompt_input.text, "/mode",
+            "right arrow mid-text must move the cursor, not accept"
+        );
+        assert_eq!(app.prompt_input.cursor, 2);
+    }
+
+    #[test]
+    fn tab_accepts_typeahead_suggestion_while_streaming() {
+        let mut app = make_app();
+        app.is_streaming = true;
+        app.prompt_input.text = "/mode".to_string();
+        app.prompt_input.cursor = app.prompt_input.text.len();
+        app.refresh_prompt_input();
+        assert!(!app.prompt_input.suggestions.is_empty());
+
+        app.handle_keybinding_action("indent");
+
+        assert_eq!(
+            app.prompt_input.text, "/model",
+            "Tab must accept the suggestion even while a turn is streaming"
+        );
+    }
+
     #[test]
     fn model_picker_accepts_openai_codex_alias() {
         let temp = tempfile::tempdir().expect("tempdir");