Add unit test

Author: jan-janssen

tests/unit/task_scheduler/interactive/test_blockallocation.py

@@ -0,0 +1,33 @@
+import queue
+import unittest
+from threading import Lock
+from concurrent.futures import Future
+
+from executorlib.task_scheduler.interactive.blockallocation import _drain_dead_worker
+from executorlib.task_scheduler.interactive.shared import task_done
+from executorlib.standalone.interactive.communication import ExecutorlibSocketError
+
+
+class TestDrainDeadWorker(unittest.TestCase):
+    def test_fail_tasks_when_no_workers_remain(self):
+        future_queue = queue.Queue()
+        alive_workers = [1]
+        alive_workers_lock = Lock()
+        future = Future()
+
+        # Add a task and then the shutdown sentinel
+        future_queue.put({"fn": lambda: 42, "future": future})
+        future_queue.put({"shutdown": True})
+
+        _drain_dead_worker(
+            future_queue=future_queue,
+            alive_workers=alive_workers,
+            alive_workers_lock=alive_workers_lock,
+        )
+
+        # Worker count should be decremented
+        self.assertEqual(alive_workers[0], 0)
+
+        # Task should fail with ExecutorlibSocketError
+        with self.assertRaises(ExecutorlibSocketError):
+            future.result()