Fix generator exception handling in database dependencies

- Add proper exception handling in get_database_session and get_optional_database_session
- Prevents 'generator didn't stop after athrow()' error when HTTPException is raised
- Add mock for BackgroundLoaderService in anime endpoint tests
- Update test expectations to match 202 Accepted response for async add_series endpoint

tests/api/test_anime_endpoints.py

@@ -1,5 +1,6 @@
 """Tests for anime API endpoints."""
 import asyncio
+from unittest.mock import AsyncMock
 
 import pytest
 from httpx import ASGITransport, AsyncClient
@@ -122,11 +123,19 @@ def reset_auth_state():
 @pytest.fixture(autouse=True)
 def mock_series_app_dependency():
     """Override the series_app dependency with FakeSeriesApp."""
+    from src.server.services.background_loader_service import (
+        get_background_loader_service,
+    )
     from src.server.utils.dependencies import get_series_app
     
     fake_app = FakeSeriesApp()
     app.dependency_overrides[get_series_app] = lambda: fake_app
     
+    # Mock background loader service
+    mock_background_loader = AsyncMock()
+    mock_background_loader.add_series_loading_task = AsyncMock()
+    app.dependency_overrides[get_background_loader_service] = lambda: mock_background_loader
+    
     yield fake_app
     
     # Clean up
@@ -262,13 +271,11 @@ async def test_add_series_endpoint_authenticated(authenticated_client):
         json={"link": "test-anime-link", "name": "Test New Anime"}
     )
     
-    # The endpoint should succeed (returns 200 or may fail if series exists)
-    assert response.status_code in (200, 400)
+    # The endpoint should succeed with 202 Accepted (async operation)
+    assert response.status_code == 202
     data = response.json()
-    
-    if response.status_code == 200:
-        assert data["status"] == "success"
-        assert "Test New Anime" in data["message"]
+    assert data["status"] == "success"
+    assert "Test New Anime" in data["message"]
 
 
 @pytest.mark.asyncio
@@ -310,7 +317,7 @@ async def test_add_series_extracts_key_from_full_url(authenticated_client):
         }
     )
     
-    assert response.status_code == 200
+    assert response.status_code == 202
     data = response.json()
     assert data["key"] == "attack-on-titan"
 
@@ -326,7 +333,7 @@ async def test_add_series_sanitizes_folder_name(authenticated_client):
         }
     )
     
-    assert response.status_code == 200
+    assert response.status_code == 202
     data = response.json()
     
     # Folder should not contain invalid characters
@@ -337,7 +344,7 @@ async def test_add_series_sanitizes_folder_name(authenticated_client):
 
 @pytest.mark.asyncio
 async def test_add_series_returns_missing_episodes(authenticated_client):
-    """Test that add_series returns missing episodes info."""
+    """Test that add_series returns loading progress info."""
     response = await authenticated_client.post(
         "/api/anime/add",
         json={
@@ -346,14 +353,13 @@ async def test_add_series_returns_missing_episodes(authenticated_client):
         }
     )
     
-    assert response.status_code == 200
+    assert response.status_code == 202
     data = response.json()
     
-    # Response should contain missing episodes fields
-    assert "missing_episodes" in data
-    assert "total_missing" in data
-    assert isinstance(data["missing_episodes"], dict)
-    assert isinstance(data["total_missing"], int)
+    # Response should contain loading_progress fields (async endpoint)
+    assert "loading_status" in data
+    assert "loading_progress" in data
+    assert isinstance(data["loading_progress"], dict)
 
 
 @pytest.mark.asyncio
@@ -367,7 +373,7 @@ async def test_add_series_response_structure(authenticated_client):
         }
     )
     
-    assert response.status_code == 200
+    assert response.status_code == 202
     data = response.json()
     
     # Verify all expected fields are present
@@ -375,8 +381,8 @@ async def test_add_series_response_structure(authenticated_client):
     assert "message" in data
     assert "key" in data
     assert "folder" in data
-    assert "missing_episodes" in data
-    assert "total_missing" in data
+    assert "loading_status" in data
+    assert "loading_progress" in data
     
     # Status should be success or exists
     assert data["status"] in ("success", "exists")
@@ -401,7 +407,7 @@ async def test_add_series_special_characters_in_name(authenticated_client):
             }
         )
         
-        assert response.status_code == 200
+        assert response.status_code == 202
         data = response.json()
         
         # Get just the folder name (last part of path)