feat: handle crashes better for the terminal state

src/main.rs

@@ -1,6 +1,7 @@
-use std::io::{self, Read, Stdout};
+use std::io::{self, Read};
 use std::time::Duration;
 
+use crossterm::cursor::Show;
 use crossterm::event::{self, Event, KeyCode};
 use crossterm::execute;
 use crossterm::terminal::{
@@ -12,6 +13,33 @@ use ratatui::layout::{Constraint, Direction, Layout};
 use ratatui::style::Style;
 use ratatui::widgets::{Block, Borders, List, ListItem, ListState};
 
+// RAII guard to ensure terminal is restored on panic/unwind
+struct TerminalModeGuard {
+    // track whether we still need to clean up
+    active: bool,
+}
+
+impl TerminalModeGuard {
+    fn new() -> Self {
+        TerminalModeGuard { active: true }
+    }
+
+    fn cleanup(&mut self) {
+        if !self.active {
+            return;
+        }
+        let _ = disable_raw_mode();
+        let mut stdout = std::io::stdout();
+        let _ = execute!(stdout, LeaveAlternateScreen, Show);
+        self.active = false;
+    }
+}
+
+impl Drop for TerminalModeGuard {
+    fn drop(&mut self) {
+        self.cleanup();
+    }
+}
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut input = String::new();
     io::stdin().read_to_string(&mut input)?;
@@ -27,6 +55,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     enable_raw_mode()?;
     let mut stdout = std::io::stdout();
     execute!(stdout, EnterAlternateScreen)?;
+
+    let mut _mode_guard = TerminalModeGuard::new();
+
     let backend = CrosstermBackend::new(stdout);
     let mut terminal = Terminal::new(backend)?;
 
@@ -63,49 +94,41 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             f.render_stateful_widget(list, chunks[0], &mut state);
         })?;
 
-        // Event handling
         if event::poll(Duration::from_millis(100))? {
             match event::read()? {
-                Event::Key(key) => {
-                    match key.code {
-                        KeyCode::Char('q') => break,
-                        KeyCode::Up => {
-                            if let Some(i) = state.selected()
-                                && i > 0
-                            {
-                                state.select(Some(i - 1));
-                            }
-                        }
-                        KeyCode::Down => {
-                            if let Some(i) = state.selected()
-                                && i + 1 < lines.len()
-                            {
-                                state.select(Some(i + 1));
-                            }
-                        }
-                        KeyCode::Char(' ') => {
-                            if let Some(i) = state.selected()
-                                && i < marked.len()
-                            {
-                                assert!(i < marked.len());
-                                if marked[i] {
-                                    marked[i] = false;
-                                } else {
-                                    marked[i] = true;
-                                    // move cursor down
-                                    let next = lines.len().min(i + 1);
-                                    state.select(Some(next));
-                                }
-                            }
-                        }
-                        KeyCode::Char('c')
-                            if key.modifiers.contains(event::KeyModifiers::CONTROL) =>
+                Event::Key(key) => match key.code {
+                    KeyCode::Char('q') => break,
+                    KeyCode::Up => {
+                        if let Some(i) = state.selected()
+                            && i > 0
                         {
-                            break;
+                            state.select(Some(i - 1));
                         }
-                        _ => {}
                     }
-                }
+                    KeyCode::Down => {
+                        if let Some(i) = state.selected()
+                            && i + 1 < lines.len()
+                        {
+                            state.select(Some(i + 1));
+                        }
+                    }
+                    KeyCode::Char(' ') => {
+                        if let Some(i) = state.selected()
+                            && i < marked.len()
+                        {
+                            assert!(i < marked.len());
+                            if !marked[i] {
+                                let next = lines.len().min(i + 1);
+                                state.select(Some(next));
+                            }
+                            marked[i] = !marked[i];
+                        }
+                    }
+                    KeyCode::Char('c') if key.modifiers.contains(event::KeyModifiers::CONTROL) => {
+                        break;
+                    }
+                    _ => {}
+                },
                 Event::Mouse(s) => {
                     if let event::MouseEventKind::Down(event::MouseButton::Left) = s.kind {
                         let area = terminal.size()?;
@@ -122,9 +145,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         }
     }
 
-    disable_raw_mode()?;
-    let mut stdout: Stdout = std::io::stdout();
-    execute!(stdout, LeaveAlternateScreen)?;
+    _mode_guard.cleanup();
     terminal.show_cursor()?;
 
     Ok(())