style: Using clippy lints

Cargo.toml

@@ -6,3 +6,12 @@ edition = "2024"
 [dependencies]
 crossterm = "0.29"
 ratatui = { version = "0.30", features = ["crossterm"] }
+
+[lints.clippy]
+pedantic = "warn"
+nursery = "warn"
+restriction = "warn"
+unused_trait_names = "warn"
+missing_docs_in_private_items = "warn"
+empty_structs_with_brackets = "warn"
+let_underscore_must_use = "warn"

src/main.rs

@@ -1,6 +1,3 @@
-use std::io::{self, Read};
-use std::time::Duration;
-
 use crossterm::event::{self, Event, KeyCode};
 use crossterm::execute;
 use crossterm::terminal::{EnterAlternateScreen, enable_raw_mode};
@@ -9,7 +6,8 @@ use ratatui::backend::CrosstermBackend;
 use ratatui::layout::{Constraint, Direction, Layout};
 use ratatui::style::Style;
 use ratatui::widgets::{Block, Borders, List, ListItem, ListState};
-
+use std::io::{self, Read as _};
+use core::time::Duration;
 mod terminal_guard;
 use terminal_guard::TerminalModeGuard;
 
@@ -29,7 +27,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut stdout = std::io::stdout();
     execute!(stdout, EnterAlternateScreen)?;
 
-    let mut _mode_guard = TerminalModeGuard::new();
+    let mut _mode_guard = TerminalModeGuard::default();
 
     let backend = CrosstermBackend::new(stdout);
     let mut terminal = Terminal::new(backend)?;
@@ -72,23 +70,17 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                 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));
+                        if let Some(i) = state.selected() {
+                            state.select(Some(i.saturating_sub(1)));
                         }
                     }
                     KeyCode::Down => {
-                        if let Some(i) = state.selected()
-                            && i + 1 < lines.len()
-                        {
-                            state.select(Some(i + 1));
+                        if let Some(i) = state.selected() {
+                            state.select(Some((i + 1).min(lines.len() - 1)));
                         }
                     }
                     KeyCode::Char(' ') => {
-                        if let Some(i) = state.selected()
-                            && i < marked.len()
-                        {
+                        if let Some(i) = state.selected() {
                             assert!(i < marked.len());
                             if !marked[i] {
                                 let next = lines.len().min(i + 1);
@@ -118,7 +110,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         }
     }
 
-    _mode_guard.cleanup();
+    drop(_mode_guard);
     terminal.show_cursor()?;
 
     Ok(())

src/terminal_guard.rs

@@ -2,28 +2,18 @@ use crossterm::cursor::Show;
 use crossterm::execute;
 use crossterm::terminal::{LeaveAlternateScreen, disable_raw_mode};
 
-pub struct TerminalModeGuard {
-    active: bool,
-}
+/// A guard that ensures the terminal is restored to its original state
+/// when dropped.
+#[derive(Default, Debug)]
+pub struct TerminalModeGuard;
 
-impl TerminalModeGuard {
-    pub fn new() -> Self {
-        Self { active: true }
-    }
+impl TerminalModeGuard {}
 
-    pub fn cleanup(&mut self) {
-        if !self.active {
-            return;
-        }
+impl Drop for TerminalModeGuard {
+    #[allow(clippy::let_underscore_must_use, reason = "We want to ignore errors during cleanup.")]
+    fn drop(&mut self) {
         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();
     }
 }