From 709e27feb2347c4345ea97d60440c8532bf119bd Mon Sep 17 00:00:00 2001
From: Zhibo Zhang <lindicaphxag@gmail.com>
Date: Mon, 2 Nov 2026 20:01:16 +0800
Subject: [PATCH] test(router): cover region filtering across async sync and
 passthrough selectors

---
 .../test_router_region_no_input.py            | 48 +++++++++++++++++--
 1 file changed, 43 insertions(+), 5 deletions(-)

diff --git a/tests/unit/test_router/test_router_region_no_input.py b/tests/unit/test_router/test_router_region_no_input.py
index 2ae769cea81..30503e1e849 100644
--- a/tests/unit/test_router/test_router_region_no_input.py
+++ b/tests/unit/test_router/test_router_region_no_input.py
@@ -2,24 +2,36 @@ import pytest
 from litellm import Router
 
 
-@pytest.mark.asyncio
-async def test_allowed_model_region_filters_requests_without_messages_or_input() -> None:
-    router = Router(
+def _router_with_region_deployments(*, pass_through: bool = False) -> Router:
+    return Router(
         model_list=[
             {
                 "model_name": "region-test",
-                "litellm_params": {"model": "openai/gpt-4o", "region_name": "eu"},
+                "litellm_params": {
+                    "model": "openai/gpt-4o",
+                    "region_name": "eu",
+                    "use_in_pass_through": pass_through,
+                },
                 "model_info": {"id": "eu-deployment"},
             },
             {
                 "model_name": "region-test",
-                "litellm_params": {"model": "openai/gpt-4o-mini", "region_name": "us"},
+                "litellm_params": {
+                    "model": "openai/gpt-4o-mini",
+                    "region_name": "us",
+                    "use_in_pass_through": pass_through,
+                },
                 "model_info": {"id": "us-deployment"},
             },
         ],
         enable_pre_call_checks=True,
     )
 
+
+@pytest.mark.asyncio
+async def test_allowed_model_region_filters_async_selection_without_messages_or_input() -> None:
+    router = _router_with_region_deployments()
+
     deployments = await router.select(
         model="region-test",
         request_kwargs={"allowed_model_region": "eu"},
@@ -29,3 +41,29 @@ async def test_allowed_model_region_filters_requests_without_messages_or_input()
     )
 
     assert [deployment["model_info"]["id"] for deployment in deployments] == ["eu-deployment"]
+
+
+def test_allowed_model_region_filters_sync_selection_without_messages_or_input() -> None:
+    router = _router_with_region_deployments()
+
+    deployment = router.get_available_deployment(
+        model="region-test",
+        request_kwargs={"allowed_model_region": "eu"},
+        messages=None,
+        input=None,
+    )
+
+    assert deployment["model_info"]["id"] == "eu-deployment"
+
+
+def test_allowed_model_region_filters_passthrough_without_messages_or_input() -> None:
+    router = _router_with_region_deployments(pass_through=True)
+
+    deployment = router.get_available_deployment_for_pass_through(
+        model="region-test",
+        request_kwargs={"allowed_model_region": "eu"},
+        messages=None,
+        input=None,
+    )
+
+    assert deployment["model_info"]["id"] == "eu-deployment"