fix: Handle entering fields without any cards in Advance action

Author: maxblan

src/plugin/action/advance.rs

@@ -1,7 +1,7 @@
 use pyo3::{pyclass, pymethods, PyErr};
 
 use crate::plugin::{
-    errors::{CannotPlayCardError, MustBuyOneCardError},
+    errors::{CannotPlayCardError, MustBuyOneCardError, MustPlayCardError},
     field::Field,
     game_state::GameState,
 };
@@ -30,15 +30,27 @@ impl Advance {
 
         player.advance_by(state, self.distance)?;
 
+        let current_field = state.board.get_field(player.position).unwrap();
+        if self.cards.is_empty() {
+            match current_field {
+                Field::Market | Field::Hare => {
+                    return Err(MustPlayCardError::new_err(
+                        "Cannot enter field without any cards",
+                    ));
+                }
+                _ => {}
+            }
+        }
+
         let mut last_card: Option<&Card> = None;
         let mut card_bought = false;
 
         for card in &self.cards {
-            match state.board.get_field(player.position).unwrap() {
+            match current_field {
+                Field::Market if card_bought => {
+                    return Err(MustBuyOneCardError::new_err("Only one card allowed to buy"));
+                }
                 Field::Market => {
-                    if card_bought {
-                        return Err(MustBuyOneCardError::new_err("Only one card allowed to buy"));
-                    }
                     player.consume_carrots(state, 10)?;
                     card_bought = true;
                     player.cards.push(*card);

src/plugin/test/advance_test.rs

@@ -62,7 +62,48 @@ mod tests {
     }
 
     #[test]
-    fn test_perform_buy_card_sucess() {
+    fn test_perform_success_without_cards() {
+        let board = Board::new(vec![
+            Field::Start,
+            Field::Position1,
+            Field::Position2,
+            Field::Hare,
+            Field::Hedgehog,
+            Field::Market,
+            Field::Hare,
+            Field::Position1,
+            Field::Goal,
+        ]);
+        let player_one = Hare::new(
+            TeamEnum::One,
+            Some(vec![Card::FallBack, Card::EatSalad, Card::SwapCarrots]),
+            Some(60),
+            Some(3),
+            None,
+            Some(0),
+        );
+        let player_two = Hare::new(
+            TeamEnum::Two,
+            Some(vec![Card::HurryAhead]),
+            Some(60),
+            Some(3),
+            None,
+            Some(0),
+        );
+
+        let mut state = GameState::new(board, 0, player_one, player_two);
+
+        let advance = Advance::new(2, vec![]);
+
+        let result = advance.perform(&mut state);
+        assert!(result.is_ok());
+
+        let current_player = state.clone_current_player();
+        assert_eq!(current_player.position, 2);
+    }
+
+    #[test]
+    fn test_perform_buy_card_success() {
         let cards = vec![Card::HurryAhead];
         let advance = Advance::new(2, cards.clone());