fix clippy warnings

battlesnake/src/logic.rs

@@ -30,7 +30,8 @@ use crate::{
 // info is called when you create your Battlesnake on play.battlesnake.com
 // and controls your Battlesnake's appearance
 // TIP: If you open your Battlesnake URL in a browser you should see this data
-#[must_use] pub fn info() -> Value {
+#[must_use]
+pub fn info() -> Value {
     info!("INFO");
 
     json!({

battlesnake/src/main.rs

@@ -3,12 +3,7 @@
 use battlesnake::{logic, Action, GameState};
 use log::{error, info};
 use rocket::{
-    fairing::AdHoc,
+    fairing::AdHoc, get, http::Status, launch, post, routes, serde::json::Json, tokio::task,
-    get,
-    http::Status,
-    launch, post, routes,
-    serde::json::Json,
-    tokio::task,
 };
 use serde_json::Value;
 use std::env;

battlesnake/src/simulation.rs

@@ -14,7 +14,13 @@ pub struct SnakeToken {
 }
 
 impl SnakeToken {
-    #[must_use] pub fn from_board(board: &crate::Board) -> BTreeMap<String, Self> {
+    /// create a token map from the current game board.
+    ///
+    /// # Panics
+    ///
+    /// This function panics when there are more than 256 snakes on the board.
+    #[must_use]
+    pub fn from_board(board: &crate::Board) -> BTreeMap<String, Self> {
         board
             .snakes
             .iter()
@@ -52,7 +58,8 @@ pub struct Board {
 }
 
 impl Board {
-    #[must_use] pub fn from_game_board(
+    #[must_use]
+    pub fn from_game_board(
         board: &crate::Board,
         token_map: &BTreeMap<String, SnakeToken>,
         turn: i32,
@@ -86,16 +93,19 @@ impl Board {
         }
     }
 
-    #[must_use] pub const fn turn(&self) -> i32 {
+    #[must_use]
+    pub const fn turn(&self) -> i32 {
         self.turn
     }
 
     #[allow(clippy::cast_sign_loss)]
-    #[must_use] pub const fn spaces(&self) -> usize {
+    #[must_use]
+    pub const fn spaces(&self) -> usize {
         self.height as usize * self.width as usize
     }
 
-    #[must_use] pub fn alive_snakes(&self) -> usize {
+    #[must_use]
+    pub fn alive_snakes(&self) -> usize {
         self.snakes.len()
     }
 
@@ -103,7 +113,8 @@ impl Board {
         self.snakes.keys().copied()
     }
 
-    #[must_use] pub fn snake_length(&self, token: SnakeToken) -> Option<usize> {
+    #[must_use]
+    pub fn snake_length(&self, token: SnakeToken) -> Option<usize> {
         self.snakes.get(&token).map(|snake| snake.body.len())
     }
 
@@ -196,7 +207,8 @@ impl Board {
         }
     }
 
-    #[must_use] pub fn possible_actions(&self) -> BTreeMap<SnakeToken, BTreeSet<Direction>> {
+    #[must_use]
+    pub fn possible_actions(&self) -> BTreeMap<SnakeToken, BTreeSet<Direction>> {
         let mut actions: BTreeMap<_, BTreeSet<_>> = self
             .snakes
             .keys()
@@ -236,11 +248,12 @@ impl Board {
             .iter()
             .sorted_unstable_by(|(_, snake1), (_, snake2)| snake2.health.cmp(&snake1.health))
             .map(|(token, snake)| {
-                if actions[token].len() == 1 {
+                let actions = &actions[token];
-                    (
+                if actions.len() == 1 {
-                        snake.body.len(),
+                    let Some(action) = actions.first() else {
-                        Some(snake.head().move_to(*actions[token].first().unwrap())),
+                        unreachable!()
-                    )
+                    };
+                    (snake.body.len(), Some(snake.head().move_to(*action)))
                 } else {
                     (snake.body.len(), None)
                 }
@@ -272,11 +285,14 @@ pub struct Battlesnake {
 }
 
 impl Battlesnake {
-    #[must_use] pub fn from_game_snake(snake: &crate::Battlesnake) -> Self {
+    #[must_use]
+    pub fn from_game_snake(snake: &crate::Battlesnake) -> Self {
         let body: VecDeque<_> = snake.body.iter().copied().collect();
-        debug_assert_eq!(body.len(), usize::try_from(snake.length).unwrap());
+        debug_assert_eq!(Ok(body.len()), usize::try_from(snake.length));
         debug_assert!(snake.health <= crate::MAX_HEALTH);
-        let health = u8::try_from(snake.health).expect("max health is 100");
+        let Ok(health) = u8::try_from(snake.health.min(100)) else {
+            unreachable!()
+        };
         Self { health, body }
     }
 
@@ -295,8 +311,9 @@ impl Battlesnake {
         self.health = self.health.saturating_sub(1);
     }
 
-    #[must_use] pub fn head(&self) -> &Coord {
+    #[must_use]
+    pub fn head(&self) -> &Coord {
         debug_assert!(!self.body.is_empty());
-        self.body.front().expect("not empty")
+        self.body.front().unwrap_or_else(|| unreachable!())
     }
 }