guardian: self guard is no longer an option

werewolves-proto/src/character.rs

@@ -504,7 +504,11 @@ impl Character {
             } => prompts.push(ActionPrompt::Guardian {
                 character_id: self.identity(),
                 previous: Some(PreviousGuardianAction::Protect(prev_target.clone())),
-                living_players: village.living_players(),
+                living_players: if prev_target.character_id == self.identity.character_id {
+                    village.living_players_excluding(prev_target.character_id)
+                } else {
+                    village.living_players()
+                },
                 marked: None,
             }),
             Role::Guardian {

werewolves-proto/src/game_test/role/guardian.rs

@@ -26,7 +26,7 @@ use crate::{
     },
     message::{
         host::{HostGameMessage, HostNightMessage},
-        night::{ActionPromptTitle, ActionResponse},
+        night::{ActionPrompt, ActionPromptTitle, ActionResponse},
     },
     role::{PreviousGuardianAction, Role, RoleTitle},
 };
@@ -271,3 +271,60 @@ fn protects_from_militia() {
         }
     );
 }
+
+#[test]
+fn cant_self_guard() {
+    init_log();
+    let players = gen_players(1..21);
+    let mut player_ids = players.iter().map(|p| p.player_id);
+    let guardian = player_ids.next().unwrap();
+    let wolf = player_ids.next().unwrap();
+    let mut settings = GameSettings::empty();
+    settings.add_and_assign(SetupRole::Guardian, guardian);
+    settings.add_and_assign(SetupRole::Werewolf, wolf);
+    settings.fill_remaining_slots_with_villagers(20);
+    let mut game = Game::new(&players, settings).unwrap();
+    game.r#continue().r#continue();
+    game.next().title().wolves_intro();
+    game.r#continue().sleep();
+    game.next_expect_day();
+
+    game.execute().title().guardian();
+    game.mark(game.character_by_player_id(guardian).character_id());
+    game.r#continue().sleep();
+
+    game.next().title().wolf_pack_kill();
+    game.mark(game.character_by_player_id(guardian).character_id());
+    game.r#continue().sleep();
+
+    game.next_expect_day();
+
+    assert_eq!(
+        game.character_by_player_id(guardian).died_to().cloned(),
+        None
+    );
+    assert_eq!(
+        game.character_by_player_id(guardian)
+            .role()
+            .guardian_ref()
+            .unwrap()
+            .last_protected
+            .clone(),
+        Some(PreviousGuardianAction::Protect(
+            game.character_by_player_id(guardian).identity()
+        ))
+    );
+
+    match game.execute() {
+        ActionPrompt::Guardian {
+            character_id,
+            previous: Some(PreviousGuardianAction::Protect(prev_protect)),
+            living_players,
+            ..
+        } => {
+            assert_eq!(character_id, prev_protect);
+            assert!(!living_players.contains(&character_id));
+        }
+        prompt => panic!("expected guardian prompt, got {prompt:?}"),
+    }
+}