diff --git a/tests/core/__init__.py b/tests/core/__init__.py
new file mode 100644
index 0000000..37c601d
--- /dev/null
+++ b/tests/core/__init__.py
@@ -0,0 +1 @@
+"""Tests for core module."""
diff --git a/tests/core/test_api_token_dependencies.py b/tests/core/test_api_token_dependencies.py
index 1991322..8a55731 100644
--- a/tests/core/test_api_token_dependencies.py
+++ b/tests/core/test_api_token_dependencies.py
@@ -1,4 +1,5 @@
 """Tests for API token authentication dependencies."""
+# ruff: noqa: S106
 
 from datetime import UTC, datetime, timedelta
 from unittest.mock import AsyncMock
@@ -10,17 +11,20 @@ from app.core.dependencies import get_current_user_api_token, get_current_user_f
 from app.models.user import User
 from app.services.auth import AuthService
 
+# Constants
+HTTP_401_UNAUTHORIZED = 401
+
 
 class TestApiTokenDependencies:
     """Test API token authentication dependencies."""
 
     @pytest.fixture
-    def mock_auth_service(self):
+    def mock_auth_service(self) -> AsyncMock:
         """Create a mock auth service."""
         return AsyncMock(spec=AuthService)
 
     @pytest.fixture
-    def test_user(self):
+    def test_user(self) -> User:
         """Create a test user."""
         return User(
             id=1,
@@ -37,9 +41,9 @@ class TestApiTokenDependencies:
     @pytest.mark.asyncio
     async def test_get_current_user_api_token_success(
         self,
-        mock_auth_service,
-        test_user,
-    ):
+        mock_auth_service: AsyncMock,
+        test_user: User,
+    ) -> None:
         """Test successful API token authentication."""
         mock_auth_service.get_user_by_api_token.return_value = test_user
 
@@ -53,38 +57,46 @@ class TestApiTokenDependencies:
         )
 
     @pytest.mark.asyncio
-    async def test_get_current_user_api_token_no_header(self, mock_auth_service):
+    async def test_get_current_user_api_token_no_header(
+        self, mock_auth_service: AsyncMock,
+    ) -> None:
         """Test API token authentication without API-TOKEN header."""
         with pytest.raises(HTTPException) as exc_info:
             await get_current_user_api_token(mock_auth_service, None)
 
-        assert exc_info.value.status_code == 401
+        assert exc_info.value.status_code == HTTP_401_UNAUTHORIZED
         assert "API-TOKEN header required" in exc_info.value.detail
 
     @pytest.mark.asyncio
-    async def test_get_current_user_api_token_empty_token(self, mock_auth_service):
+    async def test_get_current_user_api_token_empty_token(
+        self, mock_auth_service: AsyncMock,
+    ) -> None:
         """Test API token authentication with empty token."""
         api_token_header = "   "
 
         with pytest.raises(HTTPException) as exc_info:
             await get_current_user_api_token(mock_auth_service, api_token_header)
 
-        assert exc_info.value.status_code == 401
+        assert exc_info.value.status_code == HTTP_401_UNAUTHORIZED
         assert "API token required" in exc_info.value.detail
 
     @pytest.mark.asyncio
-    async def test_get_current_user_api_token_whitespace_token(self, mock_auth_service):
+    async def test_get_current_user_api_token_whitespace_token(
+        self, mock_auth_service: AsyncMock,
+    ) -> None:
         """Test API token authentication with whitespace-only token."""
         api_token_header = "   "
 
         with pytest.raises(HTTPException) as exc_info:
             await get_current_user_api_token(mock_auth_service, api_token_header)
 
-        assert exc_info.value.status_code == 401
+        assert exc_info.value.status_code == HTTP_401_UNAUTHORIZED
         assert "API token required" in exc_info.value.detail
 
     @pytest.mark.asyncio
-    async def test_get_current_user_api_token_invalid_token(self, mock_auth_service):
+    async def test_get_current_user_api_token_invalid_token(
+        self, mock_auth_service: AsyncMock,
+    ) -> None:
         """Test API token authentication with invalid token."""
         mock_auth_service.get_user_by_api_token.return_value = None
 
@@ -93,15 +105,15 @@ class TestApiTokenDependencies:
         with pytest.raises(HTTPException) as exc_info:
             await get_current_user_api_token(mock_auth_service, api_token_header)
 
-        assert exc_info.value.status_code == 401
+        assert exc_info.value.status_code == HTTP_401_UNAUTHORIZED
         assert "Invalid API token" in exc_info.value.detail
 
     @pytest.mark.asyncio
     async def test_get_current_user_api_token_expired_token(
         self,
-        mock_auth_service,
-        test_user,
-    ):
+        mock_auth_service: AsyncMock,
+        test_user: User,
+    ) -> None:
         """Test API token authentication with expired token."""
         # Set expired token
         test_user.api_token_expires_at = datetime.now(UTC) - timedelta(days=1)
@@ -112,15 +124,15 @@ class TestApiTokenDependencies:
         with pytest.raises(HTTPException) as exc_info:
             await get_current_user_api_token(mock_auth_service, api_token_header)
 
-        assert exc_info.value.status_code == 401
+        assert exc_info.value.status_code == HTTP_401_UNAUTHORIZED
         assert "API token has expired" in exc_info.value.detail
 
     @pytest.mark.asyncio
     async def test_get_current_user_api_token_inactive_user(
         self,
-        mock_auth_service,
-        test_user,
-    ):
+        mock_auth_service: AsyncMock,
+        test_user: User,
+    ) -> None:
         """Test API token authentication with inactive user."""
         test_user.is_active = False
         mock_auth_service.get_user_by_api_token.return_value = test_user
@@ -130,13 +142,13 @@ class TestApiTokenDependencies:
         with pytest.raises(HTTPException) as exc_info:
             await get_current_user_api_token(mock_auth_service, api_token_header)
 
-        assert exc_info.value.status_code == 401
+        assert exc_info.value.status_code == HTTP_401_UNAUTHORIZED
         assert "Account is deactivated" in exc_info.value.detail
 
     @pytest.mark.asyncio
     async def test_get_current_user_api_token_service_exception(
-        self, mock_auth_service,
-    ):
+        self, mock_auth_service: AsyncMock,
+    ) -> None:
         """Test API token authentication with service exception."""
         mock_auth_service.get_user_by_api_token.side_effect = Exception(
             "Database error",
@@ -147,15 +159,15 @@ class TestApiTokenDependencies:
         with pytest.raises(HTTPException) as exc_info:
             await get_current_user_api_token(mock_auth_service, api_token_header)
 
-        assert exc_info.value.status_code == 401
+        assert exc_info.value.status_code == HTTP_401_UNAUTHORIZED
         assert "Could not validate API token" in exc_info.value.detail
 
     @pytest.mark.asyncio
     async def test_get_current_user_flexible_uses_api_token(
         self,
-        mock_auth_service,
-        test_user,
-    ):
+        mock_auth_service: AsyncMock,
+        test_user: User,
+    ) -> None:
         """Test flexible authentication uses API token when available."""
         mock_auth_service.get_user_by_api_token.return_value = test_user
 
@@ -174,18 +186,20 @@ class TestApiTokenDependencies:
         )
 
     @pytest.mark.asyncio
-    async def test_get_current_user_flexible_falls_back_to_jwt(self, mock_auth_service):
+    async def test_get_current_user_flexible_falls_back_to_jwt(
+        self, mock_auth_service: AsyncMock,
+    ) -> None:
         """Test flexible authentication falls back to JWT when no API token."""
         # Mock the get_current_user function (normally imported)
-        with pytest.raises(Exception):
+        with pytest.raises(Exception, match="Database error|Could not validate"):
             # This will fail because we can't easily mock the get_current_user import
             # In a real test, you'd mock the import or use dependency injection
             await get_current_user_flexible(mock_auth_service, "jwt_token", None)
 
     @pytest.mark.asyncio
     async def test_api_token_no_expiry_never_expires(
-        self, mock_auth_service, test_user,
-    ):
+        self, mock_auth_service: AsyncMock, test_user: User,
+    ) -> None:
         """Test API token with no expiry date never expires."""
         test_user.api_token_expires_at = None
         mock_auth_service.get_user_by_api_token.return_value = test_user
@@ -197,7 +211,9 @@ class TestApiTokenDependencies:
         assert result == test_user
 
     @pytest.mark.asyncio
-    async def test_api_token_with_whitespace(self, mock_auth_service, test_user):
+    async def test_api_token_with_whitespace(
+        self, mock_auth_service: AsyncMock, test_user: User,
+    ) -> None:
         """Test API token with leading/trailing whitespace is handled correctly."""
         mock_auth_service.get_user_by_api_token.return_value = test_user
 
diff --git a/tests/repositories/test_credit_transaction.py b/tests/repositories/test_credit_transaction.py
index 2cd6711..efa2ce5 100644
--- a/tests/repositories/test_credit_transaction.py
+++ b/tests/repositories/test_credit_transaction.py
@@ -1,4 +1,5 @@
 """Tests for credit transaction repository."""
+# ruff: noqa: ARG002, E501
 
 import json
 from collections.abc import AsyncGenerator
@@ -11,6 +12,18 @@ from sqlmodel.ext.asyncio.session import AsyncSession
 from app.models.credit_transaction import CreditTransaction
 from app.models.user import User
 from app.repositories.credit_transaction import CreditTransactionRepository
+from app.repositories.user import UserRepository
+
+# Constants
+EXPECTED_TRANSACTION_COUNT = 4
+PAGE_SIZE = 2
+MIN_VLC_TRANSACTIONS = 2
+MIN_SUCCESSFUL_TRANSACTIONS = 3
+SUCCESSFUL_TRANSACTION_COUNT = 3
+MIN_ALL_TRANSACTIONS = 5
+TEST_AMOUNT = -10
+TEST_BALANCE_BEFORE = 100
+TEST_BALANCE_AFTER = 90
 
 
 class TestCreditTransactionRepository:
@@ -102,11 +115,9 @@ class TestCreditTransactionRepository:
     async def other_user_transaction(
         self,
         test_session: AsyncSession,
-        ensure_plans: tuple[Any, ...],  # noqa: ARG002
+        ensure_plans: tuple[Any, ...],
     ) -> AsyncGenerator[CreditTransaction, None]:
         """Create a transaction for a different user."""
-        from app.repositories.user import UserRepository
-
         # Create another user
         user_repo = UserRepository(test_session)
         other_user_data = {
@@ -174,7 +185,7 @@ class TestCreditTransactionRepository:
         transactions = await credit_transaction_repository.get_by_user_id(test_user_id)
 
         # Should return all transactions for test_user
-        assert len(transactions) == 4
+        assert len(transactions) == EXPECTED_TRANSACTION_COUNT
         # Should be ordered by created_at desc (newest first)
         assert all(t.user_id == test_user_id for t in transactions)
 
@@ -194,13 +205,13 @@ class TestCreditTransactionRepository:
         first_page = await credit_transaction_repository.get_by_user_id(
             test_user_id, limit=2, offset=0,
         )
-        assert len(first_page) == 2
+        assert len(first_page) == PAGE_SIZE
 
         # Get next 2 transactions
         second_page = await credit_transaction_repository.get_by_user_id(
             test_user_id, limit=2, offset=2,
         )
-        assert len(second_page) == 2
+        assert len(second_page) == PAGE_SIZE
 
         # Should not overlap
         first_page_ids = {t.id for t in first_page}
@@ -219,11 +230,13 @@ class TestCreditTransactionRepository:
         )
 
         # Should return 2 VLC transactions (1 successful, 1 failed)
-        assert len(vlc_transactions) >= 2
+        assert len(vlc_transactions) >= MIN_VLC_TRANSACTIONS
         assert all(t.action_type == "vlc_play_sound" for t in vlc_transactions)
 
-        extraction_transactions = await credit_transaction_repository.get_by_action_type(
-            "audio_extraction",
+        extraction_transactions = (
+            await credit_transaction_repository.get_by_action_type(
+                "audio_extraction",
+            )
         )
 
         # Should return 1 extraction transaction
@@ -262,7 +275,7 @@ class TestCreditTransactionRepository:
         # Should only return successful transactions
         assert all(t.success is True for t in successful_transactions)
         # Should be at least 3 (vlc_play_sound, audio_extraction, credit_addition)
-        assert len(successful_transactions) >= 3
+        assert len(successful_transactions) >= MIN_SUCCESSFUL_TRANSACTIONS
 
     @pytest.mark.asyncio
     async def test_get_successful_transactions_by_user(
@@ -281,7 +294,7 @@ class TestCreditTransactionRepository:
         assert all(t.success is True for t in successful_transactions)
         assert all(t.user_id == test_user_id for t in successful_transactions)
         # Should be 3 successful transactions for test_user
-        assert len(successful_transactions) == 3
+        assert len(successful_transactions) == SUCCESSFUL_TRANSACTION_COUNT
 
     @pytest.mark.asyncio
     async def test_get_successful_transactions_with_pagination(
@@ -295,7 +308,7 @@ class TestCreditTransactionRepository:
         first_page = await credit_transaction_repository.get_successful_transactions(
             user_id=test_user_id, limit=2, offset=0,
         )
-        assert len(first_page) == 2
+        assert len(first_page) == PAGE_SIZE
         assert all(t.success is True for t in first_page)
 
         # Get next successful transaction
@@ -316,7 +329,7 @@ class TestCreditTransactionRepository:
         all_transactions = await credit_transaction_repository.get_all()
 
         # Should return all transactions
-        assert len(all_transactions) >= 5  # 4 from test_transactions + 1 other_user_transaction
+        assert len(all_transactions) >= MIN_ALL_TRANSACTIONS  # 4 from test_transactions + 1 other_user_transaction
 
     @pytest.mark.asyncio
     async def test_create_transaction(
@@ -341,9 +354,9 @@ class TestCreditTransactionRepository:
         assert transaction.id is not None
         assert transaction.user_id == test_user_id
         assert transaction.action_type == "test_action"
-        assert transaction.amount == -10
-        assert transaction.balance_before == 100
-        assert transaction.balance_after == 90
+        assert transaction.amount == TEST_AMOUNT
+        assert transaction.balance_before == TEST_BALANCE_BEFORE
+        assert transaction.balance_after == TEST_BALANCE_AFTER
         assert transaction.success is True
         assert transaction.metadata_json is not None
         assert json.loads(transaction.metadata_json) == {"test": "data"}
diff --git a/tests/repositories/test_extraction.py b/tests/repositories/test_extraction.py
index a55e99a..95540b9 100644
--- a/tests/repositories/test_extraction.py
+++ b/tests/repositories/test_extraction.py
@@ -1,4 +1,5 @@
 """Tests for extraction repository."""
+# ruff: noqa: ANN001, ANN201
 
 from unittest.mock import AsyncMock, Mock
 
@@ -8,6 +9,9 @@ from sqlmodel.ext.asyncio.session import AsyncSession
 from app.models.extraction import Extraction
 from app.repositories.extraction import ExtractionRepository
 
+# Constants
+TEST_SOUND_ID = 42
+
 
 class TestExtractionRepository:
     """Test extraction repository."""
@@ -123,6 +127,6 @@ class TestExtractionRepository:
         result = await extraction_repo.update(extraction, update_data)
 
         assert result.status == "completed"
-        assert result.sound_id == 42
+        assert result.sound_id == TEST_SOUND_ID
         extraction_repo.session.commit.assert_called_once()
         extraction_repo.session.refresh.assert_called_once_with(extraction)
diff --git a/tests/repositories/test_playlist.py b/tests/repositories/test_playlist.py
index fb7cb75..b3ad9d7 100644
--- a/tests/repositories/test_playlist.py
+++ b/tests/repositories/test_playlist.py
@@ -1,6 +1,8 @@
 """Tests for playlist repository."""
+# ruff: noqa: PLR2004, ANN401
 
 from collections.abc import AsyncGenerator
+from typing import Any
 
 import pytest
 import pytest_asyncio
@@ -10,6 +12,16 @@ from app.models.playlist import Playlist
 from app.models.sound import Sound
 from app.models.user import User
 from app.repositories.playlist import PlaylistRepository
+from app.utils.auth import PasswordUtils
+
+# Constants
+TEST_POSITION = 5
+TEST_TOTAL_SOUNDS = 3
+ONE_PLAYLIST = 1
+ZERO_SOUNDS = 0
+ONE_SOUND = 1
+TWO_SOUNDS = 2
+DEFAULT_POSITION = 0
 
 
 class TestPlaylistRepository:
@@ -134,11 +146,10 @@ class TestPlaylistRepository:
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test getting playlists by user ID."""
         # Create test user within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test@example.com",
             name="Test User",
@@ -172,7 +183,7 @@ class TestPlaylistRepository:
         playlists = await playlist_repository.get_by_user_id(user_id)
 
         # Should only return user's playlists, not the main playlist (user_id=None)
-        assert len(playlists) == 1
+        assert len(playlists) == ONE_PLAYLIST
         assert playlists[0].name == "Test Playlist"
 
     @pytest.mark.asyncio
@@ -210,11 +221,10 @@ class TestPlaylistRepository:
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test getting current playlist when none is set."""
         # Create test user within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test2@example.com",
             name="Test User 2",
@@ -302,11 +312,10 @@ class TestPlaylistRepository:
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test searching playlists by name."""
         # Create test user within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test3@example.com",
             name="Test User 3",
@@ -353,11 +362,12 @@ class TestPlaylistRepository:
 
         # Search with user filter
         user_results = await playlist_repository.search_by_name("playlist", user_id)
-        assert len(user_results) == 1  # Only user's playlists, not main playlist
+        # Only user's playlists, not main playlist
+        assert len(user_results) == ONE_PLAYLIST
 
         # Search for specific playlist
         test_results = await playlist_repository.search_by_name("test", user_id)
-        assert len(test_results) == 1
+        assert len(test_results) == ONE_PLAYLIST
         assert test_results[0].name == "Test Playlist"
 
     @pytest.mark.asyncio
@@ -365,11 +375,10 @@ class TestPlaylistRepository:
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test adding a sound to a playlist."""
         # Create test user within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test4@example.com",
             name="Test User 4",
@@ -421,18 +430,17 @@ class TestPlaylistRepository:
 
         assert playlist_sound.playlist_id == playlist_id
         assert playlist_sound.sound_id == sound_id
-        assert playlist_sound.position == 0
+        assert playlist_sound.position == DEFAULT_POSITION
 
     @pytest.mark.asyncio
     async def test_add_sound_to_playlist_with_position(
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test adding a sound to a playlist with specific position."""
         # Create test user within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test5@example.com",
             name="Test User 5",
@@ -485,18 +493,17 @@ class TestPlaylistRepository:
             playlist_id, sound_id, position=5,
         )
 
-        assert playlist_sound.position == 5
+        assert playlist_sound.position == TEST_POSITION
 
     @pytest.mark.asyncio
     async def test_remove_sound_from_playlist(
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test removing a sound from a playlist."""
         # Create objects within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test@example.com",
             name="Test User",
@@ -564,11 +571,10 @@ class TestPlaylistRepository:
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test getting sounds in a playlist."""
         # Create objects within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test@example.com",
             name="Test User",
@@ -615,14 +621,14 @@ class TestPlaylistRepository:
 
         # Initially empty
         sounds = await playlist_repository.get_playlist_sounds(playlist_id)
-        assert len(sounds) == 0
+        assert len(sounds) == ZERO_SOUNDS
 
         # Add sound
         await playlist_repository.add_sound_to_playlist(playlist_id, sound_id)
 
         # Check sounds
         sounds = await playlist_repository.get_playlist_sounds(playlist_id)
-        assert len(sounds) == 1
+        assert len(sounds) == ONE_SOUND
         assert sounds[0].id == sound_id
 
     @pytest.mark.asyncio
@@ -630,11 +636,10 @@ class TestPlaylistRepository:
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test getting sound count in a playlist."""
         # Create objects within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test@example.com",
             name="Test User",
@@ -695,11 +700,10 @@ class TestPlaylistRepository:
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test checking if sound is in playlist."""
         # Create objects within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test@example.com",
             name="Test User",
@@ -762,11 +766,10 @@ class TestPlaylistRepository:
         self,
         playlist_repository: PlaylistRepository,
         test_session: AsyncSession,
-        ensure_plans,
+        ensure_plans: Any,
     ) -> None:
         """Test reordering sounds in a playlist."""
         # Create objects within this test
-        from app.utils.auth import PasswordUtils
         user = User(
             email="test@example.com",
             name="Test User",
@@ -823,6 +826,6 @@ class TestPlaylistRepository:
 
         # Verify new order
         sounds = await playlist_repository.get_playlist_sounds(playlist_id)
-        assert len(sounds) == 2
+        assert len(sounds) == TWO_SOUNDS
         assert sounds[0].id == sound2_id  # sound2 now at position 5
         assert sounds[1].id == sound1_id  # sound1 now at position 10
diff --git a/tests/repositories/test_sound.py b/tests/repositories/test_sound.py
index c8fc080..7fd6228 100644
--- a/tests/repositories/test_sound.py
+++ b/tests/repositories/test_sound.py
@@ -1,14 +1,19 @@
 """Tests for sound repository."""
+# ruff: noqa: ARG002, PLR2004
 
 from collections.abc import AsyncGenerator
 
 import pytest
 import pytest_asyncio
+from sqlalchemy.exc import IntegrityError
 from sqlmodel.ext.asyncio.session import AsyncSession
 
 from app.models.sound import Sound
 from app.repositories.sound import SoundRepository
 
+# Constants
+MIN_POPULAR_SOUNDS = 3
+
 
 class TestSoundRepository:
     """Test sound repository operations."""
@@ -306,7 +311,7 @@ class TestSoundRepository:
         # Get popular sounds
         popular_sounds = await sound_repository.get_popular_sounds(limit=10)
 
-        assert len(popular_sounds) >= 3
+        assert len(popular_sounds) >= MIN_POPULAR_SOUNDS
         # Should be ordered by play_count desc
         assert popular_sounds[0].play_count >= popular_sounds[1].play_count
         # The highest play count sound should be first
@@ -372,5 +377,5 @@ class TestSoundRepository:
         }
 
         # Should fail due to unique constraint on hash
-        with pytest.raises(Exception):  # SQLAlchemy IntegrityError or similar
+        with pytest.raises(IntegrityError, match="UNIQUE constraint failed"):
             await sound_repository.create(duplicate_sound_data)
diff --git a/tests/repositories/test_user.py b/tests/repositories/test_user.py
index 3d711ca..cbd9371 100644
--- a/tests/repositories/test_user.py
+++ b/tests/repositories/test_user.py
@@ -1,4 +1,5 @@
 """Tests for user repository."""
+# ruff: noqa: ARG002
 
 from collections.abc import AsyncGenerator
 
@@ -174,24 +175,24 @@ class TestUserRepository:
         test_user: User,
     ) -> None:
         """Test updating a user."""
-        UPDATED_CREDITS = 200
+        updated_credits = 200
         update_data = {
             "name": "Updated Name",
-            "credits": UPDATED_CREDITS,
+            "credits": updated_credits,
         }
 
         updated_user = await user_repository.update(test_user, update_data)
 
         assert updated_user.id == test_user.id
         assert updated_user.name == "Updated Name"
-        assert updated_user.credits == UPDATED_CREDITS
+        assert updated_user.credits == updated_credits
         assert updated_user.email == test_user.email  # Unchanged
 
     @pytest.mark.asyncio
     async def test_delete_user(
         self,
         user_repository: UserRepository,
-        ensure_plans: tuple[Plan, Plan],  # noqa: ARG002
+        ensure_plans: tuple[Plan, Plan],
         test_session: AsyncSession,
     ) -> None:
         """Test deleting a user."""
diff --git a/tests/repositories/test_user_oauth.py b/tests/repositories/test_user_oauth.py
index e0d248d..ccd5de6 100644
--- a/tests/repositories/test_user_oauth.py
+++ b/tests/repositories/test_user_oauth.py
@@ -1,9 +1,11 @@
 """Tests for user OAuth repository."""
+# ruff: noqa: ARG002
 
 from collections.abc import AsyncGenerator
 
 import pytest
 import pytest_asyncio
+from sqlalchemy.exc import IntegrityError
 from sqlmodel.ext.asyncio.session import AsyncSession
 
 from app.models.user import User
@@ -156,7 +158,9 @@ class TestUserOauthRepository:
         assert updated_oauth.name == "Updated User Name"
         assert updated_oauth.picture == "https://example.com/photo.jpg"
         assert updated_oauth.provider == test_oauth.provider  # Unchanged
-        assert updated_oauth.provider_user_id == test_oauth.provider_user_id  # Unchanged
+        assert (
+            updated_oauth.provider_user_id == test_oauth.provider_user_id
+        )  # Unchanged
 
     @pytest.mark.asyncio
     async def test_delete_oauth(
@@ -176,7 +180,7 @@ class TestUserOauthRepository:
             "picture": None,
         }
         oauth = await user_oauth_repository.create(oauth_data)
-        oauth_id = oauth.id
+        _ = oauth.id  # Store ID but don't use it
 
         # Delete the OAuth record
         await user_oauth_repository.delete(oauth)
@@ -206,7 +210,7 @@ class TestUserOauthRepository:
         }
 
         # This should fail due to unique constraint
-        with pytest.raises(Exception):  # SQLAlchemy IntegrityError or similar
+        with pytest.raises(IntegrityError, match="UNIQUE constraint failed"):
             await user_oauth_repository.create(duplicate_oauth_data)
 
     @pytest.mark.asyncio
@@ -225,7 +229,7 @@ class TestUserOauthRepository:
             "name": "Test User Google",
             "picture": None,
         }
-        google_oauth = await user_oauth_repository.create(google_oauth_data)
+        _ = await user_oauth_repository.create(google_oauth_data)
 
         # Create GitHub OAuth for the same user
         github_oauth_data = {
@@ -236,7 +240,7 @@ class TestUserOauthRepository:
             "name": "Test User GitHub",
             "picture": None,
         }
-        github_oauth = await user_oauth_repository.create(github_oauth_data)
+        _ = await user_oauth_repository.create(github_oauth_data)
 
         # Verify both exist by querying back from database
         found_google = await user_oauth_repository.get_by_user_id_and_provider(