Refactoring code for modular approach

tests/test_auth.py

@@ -66,7 +66,7 @@ class TestAuthenticationAPI:
         assert response.status_code == 401
         assert "Incorrect username or password" in response.json()["detail"]
 
-    def test_login_nonexistent_user(self, client):
+    def test_login_nonexistent_user(self, client, db):  # Added db fixture
         """Test login with nonexistent user"""
         response = client.post("/api/v1/auth/login", json={
             "username": "nonexistent",
@@ -116,4 +116,3 @@ class TestAuthManager:
         assert token_data["token_type"] == "bearer"
         assert "expires_in" in token_data
         assert isinstance(token_data["expires_in"], int)
-