fix(tests): isolate auth in vertex passthrough and spend logs date range tests (#21824)

test_vertex_passthrough_with_default_credentials and
test_view_spend_logs_with_date_range_summarized fail intermittently when a
prior xdist worker sets master_key — auth then rejects the unauthenticated
test requests before the code under test is reached.

- mock user_api_key_auth in test_vertex_passthrough_with_default_credentials
  (same pattern used for test_vertex_passthrough_with_no_default_credentials
  in #21810)
- wrap test_view_spend_logs_with_date_range_summarized in
  app.dependency_overrides[ps.user_api_key_auth] with try/finally cleanup
  (same pattern used for the other spend log tests in #21810)

tests/test_litellm/proxy/pass_through_endpoints/test_llm_pass_through_endpoints.py

@@ -446,12 +446,16 @@ class TestVertexAIPassThroughHandler:
             "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.create_pass_through_route"
         ) as mock_create_route, mock.patch(
             "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.get_vertex_pass_through_handler"
-        ) as mock_get_handler:
+        ) as mock_get_handler, mock.patch(
+            "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.user_api_key_auth",
+            new_callable=AsyncMock,
+        ) as mock_auth:
             # Mock credentials object with necessary attributes
             mock_credentials = Mock()
             mock_credentials.token = default_credentials
 
             mock_load_auth.return_value = (mock_credentials, default_project)
+            mock_auth.return_value = MagicMock()
 
             # Mock the vertex handler
             mock_handler = Mock()

tests/test_litellm/proxy/spend_tracking/test_spend_management_endpoints.py

@@ -1977,28 +1977,34 @@ async def test_view_spend_logs_with_date_range_summarized(client, monkeypatch):
     start_date = (datetime.now(timezone.utc) - timedelta(days=2)).strftime("%Y-%m-%d")
     end_date = datetime.now(timezone.utc).strftime("%Y-%m-%d")
 
-    # Call the endpoint with both start and end dates.
-    # We don't need `summarize=true` as it's the default.
-    response = client.get(
-        "/spend/logs",
-        params={
-            "start_date": start_date,
-            "end_date": end_date,
-        },
-        headers={"Authorization": "Bearer sk-test"},
+    app.dependency_overrides[ps.user_api_key_auth] = lambda: UserAPIKeyAuth(
+        user_role=LitellmUserRoles.PROXY_ADMIN
     )
+    try:
+        # Call the endpoint with both start and end dates.
+        # We don't need `summarize=true` as it's the default.
+        response = client.get(
+            "/spend/logs",
+            params={
+                "start_date": start_date,
+                "end_date": end_date,
+            },
+            headers={"Authorization": "Bearer sk-test"},
+        )
 
-    # ASSERTIONS
-    assert response.status_code == 200
-    data = response.json()
+        # ASSERTIONS
+        assert response.status_code == 200
+        data = response.json()
 
-    # Check that the response is not empty and has the summarized structure.
-    assert isinstance(data, list)
-    assert len(data) > 0
-    assert "startTime" in data[0]
-    assert "spend" in data[0]
-    assert "users" in data[0]
-    assert "models" in data[0]
+        # Check that the response is not empty and has the summarized structure.
+        assert isinstance(data, list)
+        assert len(data) > 0
+        assert "startTime" in data[0]
+        assert "spend" in data[0]
+        assert "users" in data[0]
+        assert "models" in data[0]
+    finally:
+        app.dependency_overrides.pop(ps.user_api_key_auth, None)
 
 
 @pytest.mark.asyncio