test: reproduce #198 — setup_schedule runs before lock acquisition

tests/test_issue_198.py

@@ -0,0 +1,44 @@
+import unittest
+
+from redbeat.schedulers import RedBeatScheduler, get_redis
+from tests.basecase import RedBeatCase
+
+
+class test_Issue_198(RedBeatCase):
+    """setup_schedule() runs before the distributed lock is acquired.
+
+    https://github.com/sibson/redbeat/issues/198
+
+    RedBeatScheduler.__init__ calls setup_schedule() (via the base
+    Scheduler.__init__, non-lazy) before `beat_init` ever fires, so
+    `self.lock` is still None the first time setup_schedule() writes the
+    static entries. A second instance started with a different
+    beat_schedule -- e.g. during a rolling release -- overwrites the
+    statics set the lock-holding instance is actually running, and does
+    so whether or not it goes on to win the lock.
+
+    Expected: an instance that does not hold the lock leaves an
+    existing static schedule alone.
+    Actual:   it rewrites the statics set from its own beat_schedule
+              regardless of lock state.
+
+    TRIAGE ARTIFACT -- this file is temporary. When the fix lands, move
+    this test into tests/test_scheduler.py, drop the expectedFailure
+    marker, rename it for the behaviour it checks rather than the issue
+    number, and delete this file.
+    """
+
+    @unittest.expectedFailure
+    def test_setup_schedule_without_lock_leaves_schedule_alone(self):
+        self.app.conf.beat_schedule = {'task-old': {'task': 'tasks.old', 'schedule': 60}}
+        winner = RedBeatScheduler(app=self.app, lazy=False)
+        winner.lock = object()  # simulate having acquired the distributed lock
+
+        client = get_redis(self.app)
+        self.assertEqual(client.smembers(self.app.redbeat_conf.statics_key), {'task-old'})
+
+        self.app.conf.beat_schedule = {'task-new': {'task': 'tasks.new', 'schedule': 60}}
+        loser = RedBeatScheduler(app=self.app, lazy=False)
+        self.assertIsNone(loser.lock)
+
+        self.assertEqual(client.smembers(self.app.redbeat_conf.statics_key), {'task-old'})