fix: handle /review arguments in TUI (#8823)

Handle /review <instructions> in the TUI and TUI2 by routing it as a
custom review command instead of plain text, wiring command dispatch and
adding composer coverage so typing /review text starts a review directly
rather than posting a message. User impact: /review with arguments now
kicks off the review flow, previously it would just forward as a plain
command and not actually start a review.

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

@@ -73,6 +73,7 @@ const LARGE_PASTE_CHAR_THRESHOLD: usize = 1000;
 pub enum InputResult {
     Submitted(String),
     Command(SlashCommand),
+    CommandWithArgs(SlashCommand, String),
     None,
 }
 
@@ -1274,6 +1275,18 @@ impl ChatComposer {
                     }
                 }
 
+                if !input_starts_with_space
+                    && let Some((name, rest)) = parse_slash_name(&text)
+                    && !rest.is_empty()
+                    && !name.contains('/')
+                    && let Some((_n, cmd)) = built_in_slash_commands()
+                        .into_iter()
+                        .find(|(command_name, _)| *command_name == name)
+                    && cmd == SlashCommand::Review
+                {
+                    return (InputResult::CommandWithArgs(cmd, rest.to_string()), true);
+                }
+
                 let expanded_prompt = match expand_custom_prompt(&text, &self.custom_prompts) {
                     Ok(expanded) => expanded,
                     Err(err) => {
@@ -2841,6 +2854,9 @@ mod tests {
             InputResult::Command(cmd) => {
                 assert_eq!(cmd.command(), "init");
             }
+            InputResult::CommandWithArgs(_, _) => {
+                panic!("expected command dispatch without args for '/init'")
+            }
             InputResult::Submitted(text) => {
                 panic!("expected command dispatch, but composer submitted literal text: {text}")
             }
@@ -2849,6 +2865,44 @@ mod tests {
         assert!(composer.textarea.is_empty(), "composer should be cleared");
     }
 
+    #[test]
+    fn slash_review_with_args_dispatches_command_with_args() {
+        use crossterm::event::KeyCode;
+        use crossterm::event::KeyEvent;
+        use crossterm::event::KeyModifiers;
+
+        let (tx, _rx) = unbounded_channel::<AppEvent>();
+        let sender = AppEventSender::new(tx);
+        let mut composer = ChatComposer::new(
+            true,
+            sender,
+            false,
+            "Ask Codex to do anything".to_string(),
+            false,
+        );
+
+        type_chars_humanlike(&mut composer, &['/', 'r', 'e', 'v', 'i', 'e', 'w', ' ']);
+        type_chars_humanlike(&mut composer, &['f', 'i', 'x', ' ', 't', 'h', 'i', 's']);
+
+        let (result, _needs_redraw) =
+            composer.handle_key_event(KeyEvent::new(KeyCode::Enter, KeyModifiers::NONE));
+
+        match result {
+            InputResult::CommandWithArgs(cmd, args) => {
+                assert_eq!(cmd, SlashCommand::Review);
+                assert_eq!(args, "fix this");
+            }
+            InputResult::Command(cmd) => {
+                panic!("expected args for '/review', got bare command: {cmd:?}")
+            }
+            InputResult::Submitted(text) => {
+                panic!("expected command dispatch, got literal submit: {text}")
+            }
+            InputResult::None => panic!("expected CommandWithArgs result for '/review'"),
+        }
+        assert!(composer.textarea.is_empty(), "composer should be cleared");
+    }
+
     #[test]
     fn extract_args_supports_quoted_paths_single_arg() {
         let args = extract_positional_args_for_prompt_line(
@@ -2914,6 +2968,9 @@ mod tests {
             composer.handle_key_event(KeyEvent::new(KeyCode::Enter, KeyModifiers::NONE));
         match result {
             InputResult::Command(cmd) => assert_eq!(cmd.command(), "diff"),
+            InputResult::CommandWithArgs(_, _) => {
+                panic!("expected command dispatch without args for '/diff'")
+            }
             InputResult::Submitted(text) => {
                 panic!("expected command dispatch after Tab completion, got literal submit: {text}")
             }
@@ -2947,6 +3004,9 @@ mod tests {
             InputResult::Command(cmd) => {
                 assert_eq!(cmd.command(), "mention");
             }
+            InputResult::CommandWithArgs(_, _) => {
+                panic!("expected command dispatch without args for '/mention'")
+            }
             InputResult::Submitted(text) => {
                 panic!("expected command dispatch, but composer submitted literal text: {text}")
             }