don't attach scheduled_at if not requested (#219)

Author: vellvoid

ctfcli/core/properties/scalars.py

@@ -260,7 +260,26 @@ def create_payload(self, ctx: PropertyContext) -> dict:
 
         # parse validates the timezone is explicit and raises otherwise
         parsed = self.parse(ctx.challenge.get("scheduled_at"), ctx.challenge.challenge_file_path)
-        return {"scheduled_at": parsed.isoformat() if parsed else None}
+
+        # Omit the key when there's nothing to schedule. CTFd passes the payload
+        # straight to the challenge model, so instances that predate scheduled_at
+        # (or challenge type plugins that do) fail with a 500 on an unknown key
+        if parsed is None:
+            return {}
+
+        return {"scheduled_at": parsed.isoformat()}
+
+    def sync_payload(self, ctx: PropertyContext) -> dict:
+        payload = self.create_payload(ctx)
+        if payload or self.ignored(ctx):
+            return payload
+
+        # Clearing a schedule requires an explicit null, which is only safe to send
+        # to a remote that reports the field, and therefore knows it
+        if ctx.remote_challenge is not None and "scheduled_at" in ctx.remote_challenge:
+            return {"scheduled_at": None}
+
+        return {}
 
     def pull(self, ctx: PropertyContext, remote_data: dict):
         return self.normalize(remote_data.get("scheduled_at"))

tests/core/test_challenge.py

@@ -550,7 +550,6 @@ def test_updates_simple_properties(self, mock_api_constructor: MagicMock, *args,
             "value": 150,
             "state": "hidden",
             "connection_info": "https://example.com",
-            "scheduled_at": None,
             "max_attempts": 0,
         }
 
@@ -597,7 +596,6 @@ def test_updates_attempts(self, mock_api_constructor: MagicMock, *args, **kwargs
             "state": "hidden",
             "max_attempts": 5,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -646,7 +644,6 @@ def test_updates_extra_properties(self, mock_api_constructor: MagicMock, *args,
             "application_name": "application-name",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -704,7 +701,6 @@ def test_updates_flags(self, mock_api_constructor: MagicMock, *args, **kwargs):
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -794,7 +790,6 @@ def test_updates_topics(self, mock_api_constructor: MagicMock, *args, **kwargs):
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -856,7 +851,6 @@ def test_updates_tags(self, mock_api_constructor: MagicMock, *args, **kwargs):
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -921,7 +915,6 @@ def test_updates_files(self, mock_api_constructor: MagicMock, *args, **kwargs):
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         def mock_get(*args, **kwargs):
@@ -1077,7 +1070,6 @@ def test_updates_hints_with_requirements(self, mock_api_constructor: MagicMock,
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -1185,7 +1177,6 @@ def test_updates_requirements(self, mock_api_constructor: MagicMock, *args, **kw
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -1387,7 +1378,6 @@ def test_challenge_cannot_require_itself(
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         def mock_get(*args, **kwargs):
@@ -1449,7 +1439,6 @@ def test_defaults_to_standard_challenge_type(self, mock_api_constructor: MagicMo
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -1488,7 +1477,6 @@ def test_defaults_to_visible_state(self, mock_api_constructor: MagicMock, *args,
             "value": 150,
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
             # initial patch should set the state to hidden for the duration of the update
             "state": "hidden",
         }
@@ -1542,7 +1530,6 @@ def test_does_not_update_dynamic_value(self, mock_api_constructor: MagicMock, *a
             "state": "hidden",
             "max_attempts": 0,
             "connection_info": None,
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -1602,7 +1589,6 @@ def test_updates_multiple_attributes_at_once(self, mock_api_constructor: MagicMo
             "state": "hidden",
             "max_attempts": 5,
             "connection_info": "https://example.com",
-            "scheduled_at": None,
         }
 
         mock_api: MagicMock = mock_api_constructor.return_value
@@ -1720,6 +1706,7 @@ def test_does_not_update_ignored_attributes(self):
                             "state": "hidden",
                             "max_attempts": 0,
                             "connection_info": None,
+                            # the remote reports scheduled_at, so an unset local value clears it
                             "scheduled_at": None,
                         }
 
@@ -1830,7 +1817,6 @@ def test_creates_standard_challenge(self, mock_api_constructor: MagicMock, *args
             "max_attempts": 5,
             "type": "standard",
             "connection_info": "https://example.com",
-            "scheduled_at": None,
             "extra_property": "extra_property_value",
             "state": "hidden",
         }
@@ -2035,7 +2021,6 @@ def test_does_not_set_ignored_attributes(self):
                             "state": "hidden",
                             "max_attempts": 0,
                             "connection_info": None,
-                            "scheduled_at": None,
                         }
 
                         # add a property that should be defined but ignored
@@ -2067,7 +2052,6 @@ def test_does_not_set_ignored_attributes(self):
 
                         if p == "scheduled_at":
                             challenge["scheduled_at"] = "2026-06-15T12:00:00+00:00"
-                            del expected_challenge_payload["scheduled_at"]
 
                         if p == "state":
                             challenge[p] = "new-value"
@@ -2731,7 +2715,6 @@ def test_sync_substitutes_media_in_description(self, mock_api_constructor: Magic
                 "state": "hidden",
                 "max_attempts": 0,
                 "connection_info": None,
-                "scheduled_at": None,
             },
         )
 
@@ -2873,6 +2856,9 @@ def _prop(self):
     def _payload(self, challenge, ignore=()):
         return self._prop().create_payload(PropertyContext(challenge, ignore=ignore))
 
+    def _sync_payload(self, challenge, remote_challenge=None, ignore=()):
+        return self._prop().sync_payload(PropertyContext(challenge, ignore=ignore, remote_challenge=remote_challenge))
+
     def test_parse_accepts_timezone_aware_string(self):
         parsed = self._prop().parse("2026-06-15T12:00:00+00:00")
         self.assertEqual(parsed, datetime(2026, 6, 15, 12, 0, 0, tzinfo=timezone.utc))
@@ -2908,9 +2894,33 @@ def test_payload_includes_scheduled_at_iso(self):
         # The explicit offset is preserved when sent to CTFd (CTFd normalizes server-side)
         self.assertEqual(self._payload(challenge)["scheduled_at"], "2026-06-15T14:00:00+02:00")
 
-    def test_payload_scheduled_at_none_when_absent(self):
+    def test_payload_omits_scheduled_at_when_absent(self):
+        # CTFd passes the payload straight to the challenge model, so instances
+        # (or challenge type plugins) which don't know scheduled_at fail on the key
         challenge = Challenge(self.minimal_challenge)
-        self.assertIsNone(self._payload(challenge)["scheduled_at"])
+        self.assertNotIn("scheduled_at", self._payload(challenge))
+
+    def test_sync_payload_includes_scheduled_at_iso(self):
+        challenge = Challenge(self.minimal_challenge, {"scheduled_at": "2026-06-15T14:00:00+02:00"})
+        remote = {"scheduled_at": None}
+        self.assertEqual(self._sync_payload(challenge, remote)["scheduled_at"], "2026-06-15T14:00:00+02:00")
+
+    def test_sync_payload_clears_scheduled_at_set_on_the_remote(self):
+        challenge = Challenge(self.minimal_challenge)
+        remote = {"scheduled_at": "2026-06-15T12:00:00"}
+        self.assertEqual(self._sync_payload(challenge, remote), {"scheduled_at": None})
+        self.assertEqual(self._sync_payload(challenge, {"scheduled_at": None}), {"scheduled_at": None})
+
+    def test_sync_payload_omits_scheduled_at_for_remotes_without_the_field(self):
+        # remotes which don't support scheduled_at don't return the key at all,
+        # and reject a payload carrying it
+        challenge = Challenge(self.minimal_challenge)
+        self.assertEqual(self._sync_payload(challenge, {}), {})
+
+    def test_sync_payload_omits_scheduled_at_when_ignored(self):
+        challenge = Challenge(self.minimal_challenge, {"scheduled_at": "2026-06-15T12:00:00+00:00"})
+        remote = {"scheduled_at": "2026-06-15T12:00:00"}
+        self.assertEqual(self._sync_payload(challenge, remote, ignore=("scheduled_at",)), {})
 
     def test_payload_omits_scheduled_at_when_ignored(self):
         challenge = Challenge(self.minimal_challenge, {"scheduled_at": "2026-06-15T12:00:00+00:00"})