fix(tasks): address code review feedback

- Return success=False when API key missing (blocking issue)
- Add ASSIGNED status check to prevent duplicate triggers
- Add debug logging for zero pending tasks case
- Add test for ASSIGNED status blocking

Author: Test User

codeframe/ui/routers/tasks.py

@@ -444,40 +444,54 @@ async def assign_pending_tasks(
     pending_count = len(pending_unassigned)
 
     if pending_count == 0:
+        # Debug logging to help diagnose why tasks might appear stuck
+        logger.debug(
+            f"assign_pending_tasks called for project {project_id} but found 0 pending unassigned tasks. "
+            f"Total tasks: {len(tasks)}, statuses: {[t.status.value for t in tasks]}"
+        )
         return TaskAssignmentResponse(
             success=True,
             pending_count=0,
             message="No pending unassigned tasks to assign."
         )
 
     # Check if execution is already in progress (Phase 1 fix for concurrent execution)
-    in_progress_tasks = [t for t in tasks if t.status == TaskStatus.IN_PROGRESS]
-    if in_progress_tasks:
+    # Include ASSIGNED status to prevent race between assignment and execution start
+    executing_tasks = [
+        t for t in tasks
+        if t.status in [TaskStatus.ASSIGNED, TaskStatus.IN_PROGRESS]
+    ]
+    if executing_tasks:
         logger.info(
             f"⏳ Execution already in progress for project {project_id}: "
-            f"{len(in_progress_tasks)} tasks running"
+            f"{len(executing_tasks)} tasks assigned/running"
         )
         return TaskAssignmentResponse(
             success=True,
             pending_count=pending_count,
-            message=f"Execution already in progress ({len(in_progress_tasks)} task(s) running). Please wait."
+            message=f"Execution already in progress ({len(executing_tasks)} task(s) assigned/running). Please wait."
         )
 
     # Schedule multi-agent execution in background
     api_key = os.environ.get("ANTHROPIC_API_KEY")
-    if api_key:
-        background_tasks.add_task(
-            start_development_execution,
-            project_id,
-            db,
-            manager,
-            api_key
-        )
-        logger.info(f"✅ Scheduled task assignment for project {project_id} ({pending_count} pending tasks)")
-    else:
+    if not api_key:
         logger.warning(
             f"⚠️  ANTHROPIC_API_KEY not configured - cannot assign tasks for project {project_id}"
         )
+        return TaskAssignmentResponse(
+            success=False,
+            pending_count=pending_count,
+            message="Cannot assign tasks: API key not configured. Please contact administrator."
+        )
+
+    background_tasks.add_task(
+        start_development_execution,
+        project_id,
+        db,
+        manager,
+        api_key
+    )
+    logger.info(f"✅ Scheduled task assignment for project {project_id} ({pending_count} pending tasks)")
 
     return TaskAssignmentResponse(
         success=True,

tests/ui/test_assign_pending_tasks.py

@@ -206,11 +206,12 @@ async def test_assign_pending_tasks_without_api_key(
                     current_user=mock_user
                 )
 
-        # Should still return success (pending tasks exist)
-        assert response.success is True
+        # Should return failure when API key missing
+        assert response.success is False
         assert response.pending_count == 1
+        assert "api key" in response.message.lower() or "not configured" in response.message.lower()
 
-        # But background task should NOT be scheduled
+        # Background task should NOT be scheduled
         mock_background_tasks.add_task.assert_not_called()
 
         # Should log warning
@@ -281,7 +282,7 @@ async def test_assign_pending_tasks_allowed_when_no_execution_in_progress(
         """Test that assignment proceeds when no tasks are in progress."""
         from codeframe.ui.routers.tasks import assign_pending_tasks
 
-        # Setup: Only pending and completed tasks, no in_progress
+        # Setup: Only pending and completed tasks, no in_progress or assigned
         mock_db.get_project_tasks.return_value = [
             Task(id=1, project_id=1, title="Task 1", status=TaskStatus.PENDING, assigned_to=None),
             Task(id=2, project_id=1, title="Task 2", status=TaskStatus.PENDING, assigned_to=None),
@@ -303,6 +304,35 @@ async def test_assign_pending_tasks_allowed_when_no_execution_in_progress(
         assert "started" in response.message.lower()
         mock_background_tasks.add_task.assert_called_once()
 
+    @pytest.mark.asyncio
+    async def test_assign_pending_tasks_blocked_when_tasks_assigned(
+        self, mock_db, mock_user, mock_manager, mock_background_tasks
+    ):
+        """Test that assignment is blocked when tasks are in ASSIGNED status."""
+        from codeframe.ui.routers.tasks import assign_pending_tasks
+
+        # Setup: 2 pending tasks + 1 assigned (not yet in_progress)
+        mock_db.get_project_tasks.return_value = [
+            Task(id=1, project_id=1, title="Task 1", status=TaskStatus.PENDING, assigned_to=None),
+            Task(id=2, project_id=1, title="Task 2", status=TaskStatus.PENDING, assigned_to=None),
+            Task(id=3, project_id=1, title="Task 3", status=TaskStatus.ASSIGNED, assigned_to="agent-1"),
+        ]
+
+        with patch("codeframe.ui.routers.tasks.manager", mock_manager), \
+             patch.dict(os.environ, {"ANTHROPIC_API_KEY": "test-key"}):
+            response = await assign_pending_tasks(
+                project_id=1,
+                background_tasks=mock_background_tasks,
+                db=mock_db,
+                current_user=mock_user
+            )
+
+        # Should return success but NOT schedule execution
+        assert response.success is True
+        assert response.pending_count == 2
+        assert "in progress" in response.message.lower() or "assigned" in response.message.lower()
+        mock_background_tasks.add_task.assert_not_called()
+
 
 class TestAssignPendingTasksResponseModel:
     """Tests for TaskAssignmentResponse model."""