fix: Address second code review findings (test isolation, frontend type safety)

backend/tests/api/test_api_auth.py

@@ -7,7 +7,9 @@ from ea_chatbot.history.models import User
 # We will need to mock HistoryManager and get_db dependencies later
 # For now, we define the expected behavior of the auth endpoints.
 
-client = TestClient(app)
+@pytest.fixture
+def client():
+    return TestClient(app)
 
 @pytest.fixture
 def mock_user():
@@ -19,7 +21,7 @@ def mock_user():
         theme_preference="light"
     )
 
-def test_register_user_success():
+def test_register_user_success(client):
     """Test successful user registration."""
     # We mock it where it is used in the router
     with patch("ea_chatbot.api.routers.auth.history_manager") as mock_hm:
@@ -34,7 +36,7 @@ def test_register_user_success():
         assert response.status_code == 201
         assert response.json()["email"] == "new@example.com"
 
-def test_login_success():
+def test_login_success(client):
     """Test successful login and JWT return."""
     with patch("ea_chatbot.api.routers.auth.history_manager") as mock_hm:
         mock_hm.authenticate_user.return_value = User(id="1", username="test@example.com")
@@ -48,7 +50,7 @@ def test_login_success():
         assert "access_token" in response.json()
         assert response.json()["token_type"] == "bearer"
 
-def test_login_invalid_credentials():
+def test_login_invalid_credentials(client):
     """Test login with wrong password."""
     with patch("ea_chatbot.api.routers.auth.history_manager") as mock_hm:
         mock_hm.authenticate_user.return_value = None
@@ -61,12 +63,12 @@ def test_login_invalid_credentials():
         assert response.status_code == 401
         assert "detail" in response.json()
 
-def test_protected_route_without_token():
+def test_protected_route_without_token(client):
     """Test that protected routes require a token."""
     response = client.get("/api/v1/auth/me")
     assert response.status_code == 401
 
-def test_oidc_login_redirect():
+def test_oidc_login_redirect(client):
     """Test that OIDC login returns a redirect URL and sets session cookie."""
     with patch("ea_chatbot.api.routers.auth.oidc_client") as mock_oidc:
         mock_oidc.get_auth_data.return_value = {
@@ -81,7 +83,7 @@ def test_oidc_login_redirect():
         assert response.json()["url"] == "https://oidc-provider.com/auth"
         assert "oidc_session" in response.cookies
 
-def test_oidc_callback_success():
+def test_oidc_callback_success(client):
     """Test successful OIDC callback and JWT issuance."""
     with patch("ea_chatbot.api.routers.auth.oidc_client") as mock_oidc, \
          patch("ea_chatbot.api.routers.auth.OIDCSession.decrypt") as mock_decrypt, \
@@ -105,7 +107,7 @@ def test_oidc_callback_success():
         assert response.status_code == 302
         assert "access_token" in response.cookies
 
-def test_get_me_success():
+def test_get_me_success(client):
     """Test getting current user with a valid token."""
     from ea_chatbot.api.utils import create_access_token
     token = create_access_token(data={"sub": "123"})

backend/tests/api/test_api_auth_cookie.py

@@ -5,7 +5,9 @@ from ea_chatbot.api.main import app
 from ea_chatbot.history.models import User
 from ea_chatbot.api.utils import create_access_token
 
-client = TestClient(app)
+@pytest.fixture
+def client():
+    return TestClient(app)
 
 @pytest.fixture
 def mock_user():
@@ -17,7 +19,7 @@ def mock_user():
         theme_preference="light"
     )
 
-def test_v1_prefix():
+def test_v1_prefix(client):
     """Test that routes are prefixed with /api/v1."""
     # This should now be 404
     response = client.get("/auth/me")
@@ -27,7 +29,7 @@ def test_v1_prefix():
     response = client.get("/api/v1/auth/me")
     assert response.status_code == 401
 
-def test_login_sets_cookie():
+def test_login_sets_cookie(client):
     """Test that login sets the access_token cookie."""
     with patch("ea_chatbot.api.routers.auth.history_manager") as mock_hm:
         mock_hm.authenticate_user.return_value = User(id="1", username="test@example.com")
@@ -45,7 +47,7 @@ def test_login_sets_cookie():
         assert "access_token" in set_cookie
         assert "HttpOnly" in set_cookie
 
-def test_register_sets_cookie():
+def test_register_sets_cookie(client):
     """Test that register sets the access_token cookie."""
     with patch("ea_chatbot.api.routers.auth.history_manager") as mock_hm:
         mock_hm.get_user.return_value = None
@@ -59,7 +61,7 @@ def test_register_sets_cookie():
         assert response.status_code == 201
         assert "access_token" in response.cookies
 
-def test_auth_via_cookie():
+def test_auth_via_cookie(client):
     """Test that protected routes work with the access_token cookie."""
     token = create_access_token(data={"sub": "123"})
     
@@ -73,7 +75,7 @@ def test_auth_via_cookie():
         assert response.status_code == 200
         assert response.json()["email"] == "test@example.com"
 
-def test_logout_clears_cookie():
+def test_logout_clears_cookie(client):
     """Test that logout endpoint clears the cookie."""
     response = client.post("/api/v1/auth/logout")
     assert response.status_code == 200
@@ -81,7 +83,7 @@ def test_logout_clears_cookie():
     cookie = response.cookies.get("access_token")
     assert not cookie or cookie == ""
 
-def test_oidc_callback_redirects_with_cookie():
+def test_oidc_callback_redirects_with_cookie(client):
     """Test that OIDC callback sets cookie and redirects."""
     with patch("ea_chatbot.api.routers.auth.oidc_client") as mock_oidc, \
          patch("ea_chatbot.api.routers.auth.OIDCSession.decrypt") as mock_decrypt, \

backend/tests/api/test_theme.py

@@ -5,7 +5,9 @@ from ea_chatbot.api.main import app
 from ea_chatbot.history.models import User
 from ea_chatbot.api.utils import create_access_token
 
-client = TestClient(app)
+@pytest.fixture
+def client():
+    return TestClient(app)
 
 @pytest.fixture
 def test_user():
@@ -20,7 +22,7 @@ def test_user():
 def auth_token():
     return create_access_token(data={"sub": "user-123"})
 
-def test_get_me_includes_theme(test_user, auth_token):
+def test_get_me_includes_theme(client, test_user, auth_token):
     """Test that /auth/me returns the theme_preference."""
     with patch("ea_chatbot.api.dependencies.history_manager") as mock_hm:
         mock_hm.get_user_by_id.return_value = test_user
@@ -33,7 +35,7 @@ def test_get_me_includes_theme(test_user, auth_token):
         assert "theme_preference" in data
         assert data["theme_preference"] == "light"
 
-def test_update_theme_success(test_user, auth_token):
+def test_update_theme_success(client, test_user, auth_token):
     """Test successful theme update via PATCH /auth/theme."""
     updated_user = User(
         id="user-123",
@@ -62,7 +64,7 @@ def test_update_theme_success(test_user, auth_token):
         assert data["theme_preference"] == "dark"
         mock_hm_router.update_user_theme.assert_called_once_with("user-123", "dark")
 
-def test_update_theme_unauthorized():
+def test_update_theme_unauthorized(client):
     """Test that theme update requires authentication."""
     response = client.patch(
         "/api/v1/auth/theme",