test(proxy): align favicon remote asset expectations

tests/proxy_unit_tests/test_get_favicon.py

@@ -1,6 +1,5 @@
 import os
 import sys
-from unittest import mock
 
 sys.path.insert(0, os.path.abspath("../.."))
 
@@ -26,50 +25,30 @@ async def test_get_favicon_default():
 
 
 @pytest.mark.asyncio
-async def test_get_favicon_with_custom_url():
-    """Test that get_favicon fetches from a custom URL."""
-    os.environ["LITELLM_FAVICON_URL"] = "https://example.com/favicon.ico"
+async def test_get_favicon_with_custom_url(monkeypatch):
+    """Test that get_favicon redirects browser-loaded custom URLs."""
+    monkeypatch.setenv("LITELLM_FAVICON_URL", "https://example.com/favicon.ico")
 
-    mock_response = mock.Mock()
-    mock_response.status_code = 200
-    mock_response.content = b"\x00\x00\x01\x00"
-    mock_response.headers = {"content-type": "image/x-icon"}
+    async with httpx.AsyncClient(
+        transport=httpx.ASGITransport(app=app),
+        base_url="http://testserver",
+    ) as ac:
+        response = await ac.get("/get_favicon")
 
-    try:
-        with mock.patch(
-            "litellm.llms.custom_httpx.http_handler.AsyncHTTPHandler.get"
-        ) as mock_get:
-            mock_get.return_value = mock_response
-
-            async with httpx.AsyncClient(
-                transport=httpx.ASGITransport(app=app),
-                base_url="http://testserver",
-            ) as ac:
-                response = await ac.get("/get_favicon")
-
-            assert response.status_code == 200
-            assert response.headers["content-type"] == "image/x-icon"
-    finally:
-        os.environ.pop("LITELLM_FAVICON_URL", None)
+    assert response.status_code == 307
+    assert response.headers["location"] == "https://example.com/favicon.ico"
 
 
 @pytest.mark.asyncio
-async def test_get_favicon_url_error_fallback():
-    """Test that get_favicon falls back to default on error."""
-    os.environ["LITELLM_FAVICON_URL"] = "https://invalid.com/favicon.ico"
+async def test_get_favicon_remote_url_is_not_server_fetched(monkeypatch):
+    """Test that get_favicon does not validate remote URLs server-side."""
+    monkeypatch.setenv("LITELLM_FAVICON_URL", "https://invalid.com/favicon.ico")
 
-    try:
-        with mock.patch(
-            "litellm.llms.custom_httpx.http_handler.AsyncHTTPHandler.get"
-        ) as mock_get:
-            mock_get.side_effect = httpx.ConnectError("unreachable")
+    async with httpx.AsyncClient(
+        transport=httpx.ASGITransport(app=app),
+        base_url="http://testserver",
+    ) as ac:
+        response = await ac.get("/get_favicon")
 
-            async with httpx.AsyncClient(
-                transport=httpx.ASGITransport(app=app),
-                base_url="http://testserver",
-            ) as ac:
-                response = await ac.get("/get_favicon")
-
-            assert response.status_code in [200, 404]
-    finally:
-        os.environ.pop("LITELLM_FAVICON_URL", None)
+    assert response.status_code == 307
+    assert response.headers["location"] == "https://invalid.com/favicon.ico"