chore: stabilize backend tests by resolving race conditions

Author: manishklach

backend/tests/test_job_service.py

@@ -4,6 +4,8 @@
 from app.storage.manager import LocalStorageManager
 from app.models.project import Job
 
+import threading
+
 class MockStorage(LocalStorageManager):
     def __init__(self):
         self.jobs = {}
@@ -19,17 +21,23 @@ def test_job_service_success_lifecycle():
     storage = MockStorage()
     service = JobService(storage)
 
-    # Task that returns a result
+    # Use an event to pause the background task
+    task_start_event = threading.Event()
+    
     def success_task(job):
+        task_start_event.wait() # Wait for signal
         return {"final_status": "success", "asset": "video.mp4"}
 
     job = service.start_job("proj_123", "render", success_task)
 
-    # Check initial state
-    assert job.status == "queued"
+    # Check initial state (might be queued or already running due to fast orchestration)
+    assert job.status in ["queued", "running"]
     assert job.project_id == "proj_123"
 
-    # Poll for completion (it runs in a ThreadPoolExecutor)
+    # Signal task to proceed
+    task_start_event.set()
+    
+    # Poll for completion
     max_wait = 5
     start_time = time.time()
     while time.time() - start_time < max_wait:
@@ -46,12 +54,19 @@ def test_job_service_failure_lifecycle():
     storage = MockStorage()
     service = JobService(storage)
 
-    # Task that raises an exception
+    task_start_event = threading.Event()
+    
     def failing_task(job):
+        task_start_event.wait()
         raise ValueError("Simulated provider failure")
 
     job = service.start_job("proj_456", "video", failing_task)
 
+    # Safe to check queued or running
+    assert job.status in ["queued", "running"]
+    
+    task_start_event.set()
+    
     # Poll for failure
     max_wait = 5
     start_time = time.time()