fix: harden twenty four game submissions

backend/contest/game_services.py

@@ -1,5 +1,6 @@
 import ast
 import secrets
+import unicodedata
 from collections import Counter
 from fractions import Fraction
 
@@ -36,6 +37,18 @@ TWENTY_FOUR_PUZZLES = {
     MathGameAttempt.Difficulty.HARD: [(1, 5, 5, 5), (3, 3, 7, 7), (5, 5, 7, 11)],
 }
 
+TWENTY_FOUR_SYMBOLS = str.maketrans(
+    {
+        "×": "*",
+        "·": "*",
+        "∙": "*",
+        "÷": "/",
+        "−": "-",
+        "–": "-",
+        "—": "-",
+    }
+)
+
 
 def _grid_from_text(value):
     return [[int(value[row * 9 + column]) for column in range(9)] for row in range(9)]
@@ -80,7 +93,10 @@ def start_game(user, kind, difficulty):
 
 
 def _validate_twenty_four_expression(source, numbers):
-    source = str(source or "").strip()
+    source = unicodedata.normalize("NFKC", str(source or "")).translate(
+        TWENTY_FOUR_SYMBOLS
+    )
+    source = source.strip()
     if not source or len(source) > 120:
         raise ValidationError({"expression": "请输入不超过 120 个字符的表达式"})
     try:
@@ -90,7 +106,11 @@ def _validate_twenty_four_expression(source, numbers):
     used = []
 
     def evaluate(node):
-        if isinstance(node, ast.Constant) and isinstance(node.value, int):
+        if (
+            isinstance(node, ast.Constant)
+            and isinstance(node.value, int)
+            and not isinstance(node.value, bool)
+        ):
             used.append(node.value)
             return Fraction(node.value)
         if isinstance(node, ast.BinOp) and isinstance(

backend/contest/test_game_services.py

@@ -47,6 +47,55 @@ def test_twenty_four_服务端校验数字使用与幂等提交(game_user):
     assert replay["score"] == result["score"]
 
 
+@pytest.mark.django_db
+def test_twenty_four_api_兼容常见数学符号并完成计分(client, game_user):
+    attempt = MathGameAttempt.objects.create(
+        user=game_user,
+        kind=MathGameAttempt.Kind.TWENTY_FOUR,
+        puzzle={"numbers": [1, 3, 4, 6]},
+        solution={"target": 24},
+    )
+    client.force_login(game_user)
+
+    response = client.post(
+        f"/api/v1/contests/games/attempts/{attempt.id}/submit/",
+        {"expression": "６÷（１−３÷４）"},
+        content_type="application/json",
+        HTTP_IDEMPOTENCY_KEY="unicode-game-submit",
+    )
+
+    assert response.status_code == 200
+    assert response.json()["status"] == MathGameAttempt.Status.COMPLETED
+    assert response.json()["score"] >= 100
+    attempt.refresh_from_db()
+    assert attempt.submission == {"expression": "6/(1-3/4)"}
+
+
+@pytest.mark.django_db
+def test_twenty_four_api_答案错误时返回具体原因和请求编号(client, game_user):
+    attempt = MathGameAttempt.objects.create(
+        user=game_user,
+        kind=MathGameAttempt.Kind.TWENTY_FOUR,
+        puzzle={"numbers": [1, 3, 4, 6]},
+        solution={"target": 24},
+    )
+    client.force_login(game_user)
+
+    response = client.post(
+        f"/api/v1/contests/games/attempts/{attempt.id}/submit/",
+        {"expression": "1 + 3 + 4 + 6"},
+        content_type="application/json",
+        HTTP_IDEMPOTENCY_KEY="incorrect-game-submit",
+        HTTP_X_REQUEST_ID="twenty-four-invalid-test",
+    )
+
+    assert response.status_code == 400
+    assert response.json()["error"]["message"] == "当前结果是 14，还没有得到 24"
+    assert response.json()["error"]["request_id"] == "twenty-four-invalid-test"
+    attempt.refresh_from_db()
+    assert attempt.status == MathGameAttempt.Status.ACTIVE
+
+
 @pytest.mark.django_db
 def test_twenty_four_拒绝额外数字和非四则表达式(game_user):
     attempt = MathGameAttempt.objects.create(
@@ -70,6 +119,13 @@ def test_twenty_four_拒绝额外数字和非四则表达式(game_user):
             {"expression": "pow(2, 3) * 3"},
             "invalid-function",
         )
+    with pytest.raises(ValidationError, match="只允许"):
+        submit_game(
+            game_user,
+            attempt.id,
+            {"expression": "6 / (True - 3 / 4)"},
+            "invalid-boolean",
+        )
 
 
 @pytest.mark.django_db