From 8b3c2166d8990a3560bd391708ce31009fe72673 Mon Sep 17 00:00:00 2001
From: kerry <kerry@berri.ai>
Date: Tue, 22 Sep 2026 20:44:58 +0000
Subject: [PATCH] test(integration): budget_duration change on /budget/update
 recomputes budget_reset_at (Pylon #6913)

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---
 tests/integration/contracts.json              |  3 ++
 .../management/test_budget_updates.py         | 28 +++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 tests/integration/management/test_budget_updates.py

diff --git a/tests/integration/contracts.json b/tests/integration/contracts.json
index c06e0271d45..4f06470a9dd 100644
--- a/tests/integration/contracts.json
+++ b/tests/integration/contracts.json
@@ -33,6 +33,9 @@
     "tests/integration/management/test_key_updates.py::test_update_preserves_independent_fields_and_serving": [
       "mgmt.key.update.preserves_independent_fields"
     ],
+    "tests/integration/management/test_budget_updates.py::test_shortening_budget_duration_moves_reset_at_onto_the_new_schedule": [
+      "mgmt.budget.update.duration_change_recomputes_reset_at"
+    ],
     "tests/integration/pricing/test_configured_prices.py::test_custom_price_is_reported_and_charged": [
       "quota_management.spend_tracking.custom_price.matches_input_rates"
     ],
diff --git a/tests/integration/management/test_budget_updates.py b/tests/integration/management/test_budget_updates.py
new file mode 100644
index 00000000000..45ec6102ca5
--- /dev/null
+++ b/tests/integration/management/test_budget_updates.py
@@ -0,0 +1,28 @@
+from datetime import datetime
+from typing import Final
+
+import pytest
+
+from tests.integration._support.client import Gateway, string_value
+from tests.integration._support.database import read_rows
+
+
+def _persisted_reset_at(budget_id: str) -> datetime:
+    rows: Final = read_rows(
+        'SELECT budget_reset_at::text AS reset_at FROM "LiteLLM_BudgetTable" WHERE budget_id = %s', (budget_id,)
+    )
+    assert len(rows) == 1, rows
+    return datetime.fromisoformat(string_value(rows[0]["reset_at"]))
+
+
+@pytest.mark.covers("mgmt.budget.update.duration_change_recomputes_reset_at")
+def test_shortening_budget_duration_moves_reset_at_onto_the_new_schedule(gateway: Gateway) -> None:
+    with gateway.scenario() as scenario:
+        budget_id: Final = scenario.budget(max_budget=10.0, budget_duration="30d")
+        monthly_reset_at: Final = _persisted_reset_at(budget_id)
+        response: Final = gateway.request("POST", "/budget/update", {"budget_id": budget_id, "budget_duration": "1d"})
+        assert response.status_code == 200, response.text
+        control_id: Final = scenario.budget(max_budget=10.0, budget_duration="1d")
+        daily_reset_at: Final = _persisted_reset_at(control_id)
+        assert daily_reset_at < monthly_reset_at, f"{daily_reset_at} vs {monthly_reset_at}"
+        assert _persisted_reset_at(budget_id) == daily_reset_at, response.text