feat!: Replace assert with ValueError for tile count validation in Shanten.calculate_shanten_for_regular_hand() (#184)

Author: Apricot-S

CHANGELOG.md

@@ -92,6 +92,7 @@ The following methods are now available as static methods:
 - Yaku calculation order has changed: chinitsu/honitsu are now mutually exclusive, and tsuisou/honroto/chinroto checks now require no chi sets. Users manually overwriting `config.yaku` fields may be affected.
 - Yakuhai detection (hatsu, haku, chun, winds) now uses `has_pon_or_kan_of()` instead of counting triplets. Behavior changes for invalid hands with two or more identical triplets of the same tile.
 - Fixed an issue where `KokushiMusou.is_condition_met()` would return `None` if the condition was not met. It now consistently returns a `bool` value. Remove any `None` checks in the code that relied on the previous behavior.
+- `Shanten.calculate_shanten()` and `Shanten.calculate_shanten_for_regular_hand()` now raises `ValueError` instead of `assert` when the number of tiles is 15 or more.
 
 ## What's Changed
 - Placeholder. It would be filled on release automatically

mahjong/shanten.py

@@ -69,7 +69,9 @@ def __init__(self, tiles_34: Sequence[int]) -> None:
 
     def calculate(self) -> int:
         count_of_tiles = sum(self._tiles)
-        assert count_of_tiles <= 14, f"Too many tiles = {count_of_tiles}"
+        if count_of_tiles > 14:
+            msg = f"Too many tiles = {count_of_tiles}"
+            raise ValueError(msg)
 
         self._remove_character_tiles(count_of_tiles)
 

tests/tests_shanten.py

@@ -19,6 +19,12 @@ def test_calculate_shanten(sou: str, pin: str, man: str, honors: str, shanten_nu
     assert shanten.calculate_shanten(tiles) == shanten_number
 
 
+def test_calculate_shanten_raises_error_too_many_tiles() -> None:
+    tiles = TilesConverter.string_to_34_array(sou="1111", pin="1111", man="1111", honors="111")
+    with pytest.raises(ValueError, match="Too many tiles = 15"):
+        Shanten.calculate_shanten(tiles)
+
+
 @pytest.mark.parametrize(
     ("sou", "pin", "man", "honors", "shanten_number"),
     [