feat: 存在しないcontest_idでリクエストしたときただのnullが返ってたのをjsonの中に入れるようにした

src/domain/Contest/database/contest_repository.py

@@ -19,4 +19,6 @@ def find(self, contest_id: str) -> Contest:
         row = self.sqlhandler.query(
             "SELECT * FROM contests WHERE contest_id=%s", (contest_id,)
         ).fetch_one()
+        if len(row) == 0:
+            return None
         return Contest(*row)

src/interface/controllers/contest_controller.py

@@ -16,5 +16,11 @@ async def contests(self, req, resp):
 
     async def contest(self, req, resp, *, contest_id):
         contest = self.interactor.contest(contest_id)
-        resp.media = {"contest": contest.as_json()}
-        resp.status_code = 200
+        if contest is None:
+            res_data = None
+            res_code = 400
+        else:
+            res_data = contest.as_json()
+            res_code = 200
+        resp.media = {"contest": res_data}
+        resp.status_code = res_code