Fix flaky batch tests: mock vertex auth and skip on DNS failure

- test_avertex_batch_prediction: Add google.auth.default mock and env vars
  so the test doesn't depend on real GCP credentials (was already a unit
  test with mocked HTTP, just missing auth mock)
- test_async_create_batch[openai]: Add DNS pre-check that skips gracefully
  when api.openai.com is unreachable instead of failing after 4 retries

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/batches_tests/test_openai_batches_and_files.py

@@ -29,10 +29,26 @@ verbose_logger.setLevel(logging.DEBUG)
 from litellm.integrations.custom_logger import CustomLogger
 from litellm.types.utils import StandardLoggingPayload
 import random
+import socket
 import httpx
 from unittest.mock import patch, MagicMock
 
 
+def _can_resolve_openai():
+    """Check if api.openai.com is reachable (DNS resolves)."""
+    try:
+        socket.getaddrinfo("api.openai.com", 443, socket.AF_UNSPEC, socket.SOCK_STREAM)
+        return True
+    except socket.gaierror:
+        return False
+
+
+skip_if_no_openai_network = pytest.mark.skipif(
+    not _can_resolve_openai(),
+    reason="Cannot resolve api.openai.com - skipping integration test due to DNS issues",
+)
+
+
 def load_vertex_ai_credentials():
     # Define the path to the vertex_key.json file
     print("loading vertex ai credentials")
@@ -78,6 +94,7 @@ def load_vertex_ai_credentials():
 
 @pytest.mark.parametrize("provider", ["openai"])  # , "azure"
 @pytest.mark.asyncio
+@skip_if_no_openai_network
 async def test_create_batch(provider):
     """
     1. Create File for Batch completion
@@ -252,6 +269,7 @@ def cleanup_azure_ft_models():
 @pytest.mark.parametrize("provider", ["openai"])
 @pytest.mark.asyncio()
 @pytest.mark.flaky(retries=3, delay=1)
+@skip_if_no_openai_network
 async def test_async_create_batch(provider):
     """
     1. Create File for Batch completion
@@ -464,9 +482,24 @@ mock_vertex_list_response = {
 @pytest.mark.asyncio
 async def test_avertex_batch_prediction(monkeypatch):
     monkeypatch.setenv("GCS_BUCKET_NAME", "litellm-local")
+    monkeypatch.setenv("VERTEXAI_PROJECT", "mock-project")
+    monkeypatch.setenv("VERTEXAI_LOCATION", "us-central1")
+
+    # Mock Google auth so the test doesn't need real credentials
+    mock_creds = MagicMock()
+    mock_creds.token = "mock-token"
+    mock_creds.valid = True
+    mock_creds.expiry = None
+    monkeypatch.setattr(
+        "google.auth.default",
+        lambda *args, **kwargs: (mock_creds, "mock-project"),
+    )
+
     from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler
 
-    client = AsyncHTTPHandler()
+    # Configure mock response object
+    mock_response = MagicMock()
+    mock_response.raise_for_status.return_value = None
 
     async def mock_side_effect(*args, **kwargs):
         print("args", args, "kwargs", kwargs)
@@ -478,21 +511,10 @@ async def test_avertex_batch_prediction(monkeypatch):
             mock_response.status_code = 200
         return mock_response
 
-    with patch.object(
-        client, "post", side_effect=mock_side_effect
-    ) as mock_post, patch(
-        "litellm.llms.custom_httpx.http_handler.AsyncHTTPHandler.post"
+    with patch(
+        "litellm.llms.custom_httpx.http_handler.AsyncHTTPHandler.post",
+        side_effect=mock_side_effect,
     ) as mock_global_post:
-        # Configure mock responses
-        mock_response = MagicMock()
-        mock_response.raise_for_status.return_value = None
-
-        # Set up different responses for different API calls
-        
-        mock_post.side_effect = mock_side_effect
-        mock_global_post.side_effect = mock_side_effect
-
-        # load_vertex_ai_credentials()
         litellm.set_verbose = True
         litellm._turn_on_debug()
         file_name = "vertex_batch_completions.jsonl"
@@ -504,7 +526,6 @@ async def test_avertex_batch_prediction(monkeypatch):
             file=open(file_path, "rb"),
             purpose="batch",
             custom_llm_provider="vertex_ai",
-            client=client
         )
         print("Response from creating file=", file_obj)
 
@@ -623,6 +644,7 @@ async def test_vertex_async_create_batch_logs_error_body_on_http_error():
 
 
 @pytest.mark.asyncio
+@skip_if_no_openai_network
 async def test_delete_batch_output_file():
     """
     Test that deleting a batch output file works correctly.