From 295ea7326a29587f5c5c30757f975e3ac1043e7d Mon Sep 17 00:00:00 2001
From: Ishaan Jaff <ishaan@berri.ai>
Date: Wed, 30 Sep 2026 00:40:11 -0700
Subject: [PATCH] test(tracing): cover TraceReceiver ingest, tenant stamping
 and backpressure

---
 tests/test_litellm/tracing/test_receiver.py | 112 ++++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 tests/test_litellm/tracing/test_receiver.py

diff --git a/tests/test_litellm/tracing/test_receiver.py b/tests/test_litellm/tracing/test_receiver.py
new file mode 100644
index 00000000000..0cbaabee9eb
--- /dev/null
+++ b/tests/test_litellm/tracing/test_receiver.py
@@ -0,0 +1,112 @@
+"""
+Tests for TraceReceiver.ingest (litellm/tracing/receiver.py) with a fake store.
+"""
+
+import os
+import sys
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, patch
+
+sys.path.insert(0, os.path.abspath("../../.."))
+
+import pytest
+from opentelemetry.proto.collector.trace.v1.trace_service_pb2 import ExportTraceServiceRequest
+from opentelemetry.proto.common.v1.common_pb2 import AnyValue, KeyValue
+from opentelemetry.proto.trace.v1.trace_pb2 import ResourceSpans, ScopeSpans, Span
+
+from litellm.tracing import receiver as receiver_module
+from litellm.tracing import Tenant, TraceReceiver, TracingBackpressureError, TracingPayloadTooLargeError
+
+FIXTURE = Path(__file__).parent / "fixtures" / "langsmith_deep_agent_export.json"
+TENANT = Tenant(team_id="team-research", api_key_hash="hashed-key", org_id="org-1")
+
+
+def _fake_store(full: bool = False) -> MagicMock:
+    store = MagicMock()
+    store.is_full.return_value = full
+    store.flush = AsyncMock()
+    store.get_trace = AsyncMock(return_value=None)
+    return store
+
+
+def _spoofed_export() -> bytes:
+    """A client that tries to claim another team via resource attributes."""
+    resource_spans = ResourceSpans(scope_spans=[ScopeSpans(spans=[Span(trace_id=b"\x01" * 16, span_id=b"\x02" * 8)])])
+    resource_spans.resource.attributes.extend(
+        [
+            KeyValue(key="service.name", value=AnyValue(string_value="svc")),
+            KeyValue(key="litellm.team_id", value=AnyValue(string_value="someone-elses-team")),
+            KeyValue(key="litellm.api_key_hash", value=AnyValue(string_value="someone-elses-key")),
+        ]
+    )
+    return ExportTraceServiceRequest(resource_spans=[resource_spans]).SerializeToString()
+
+
+@pytest.mark.asyncio
+async def test_ingest_returns_span_count_and_writes_stamped_rows():
+    store = _fake_store()
+    count = await TraceReceiver(store).ingest(FIXTURE.read_bytes(), "application/json", None, TENANT)
+    assert count == 6
+    (rows,) = store.write_spans.call_args.args
+    assert len(rows) == 6
+    for row in rows:
+        assert (row["TeamId"], row["ApiKeyHash"]) == ("team-research", "hashed-key")
+        assert row["ResourceAttributes"]["litellm.org_id"] == "org-1"
+        assert row["ResourceAttributes"]["service.name"] == "agent-demo"
+
+
+@pytest.mark.asyncio
+async def test_ingest_overwrites_client_supplied_tenant_attributes():
+    store = _fake_store()
+    await TraceReceiver(store).ingest(_spoofed_export(), "application/x-protobuf", None, TENANT)
+    ((row,),) = store.write_spans.call_args.args
+    assert row["TeamId"] == "team-research"
+    assert row["ResourceAttributes"]["litellm.team_id"] == "team-research"
+    assert row["ResourceAttributes"]["litellm.api_key_hash"] == "hashed-key"
+
+
+@pytest.mark.asyncio
+async def test_ingest_raises_backpressure_when_buffer_full():
+    store = _fake_store(full=True)
+    with pytest.raises(TracingBackpressureError):
+        await TraceReceiver(store).ingest(FIXTURE.read_bytes(), "application/json", None, TENANT)
+    store.write_spans.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_ingest_rejects_oversized_body():
+    store = _fake_store()
+    with patch.object(receiver_module, "OTLP_MAX_BODY_BYTES", 10):
+        with pytest.raises(TracingPayloadTooLargeError):
+            await TraceReceiver(store).ingest(FIXTURE.read_bytes(), "application/json", None, TENANT)
+    store.write_spans.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_large_body_is_decoded_off_the_event_loop():
+    store = _fake_store()
+    with (
+        patch.object(receiver_module, "OTLP_OFFLOAD_DECODE_BYTES", 0),
+        patch.object(receiver_module.asyncio, "to_thread", wraps=receiver_module.asyncio.to_thread) as to_thread,
+    ):
+        count = await TraceReceiver(store).ingest(FIXTURE.read_bytes(), "application/json", None, TENANT)
+    assert count == 6
+    to_thread.assert_called_once()
+
+
+@pytest.mark.asyncio
+async def test_empty_export_writes_nothing():
+    store = _fake_store()
+    assert await TraceReceiver(store).ingest(b"", "application/x-protobuf", None, TENANT) == 0
+    store.write_spans.assert_called_once_with([])
+
+
+@pytest.mark.asyncio
+async def test_reads_and_flush_delegate_to_store():
+    store = _fake_store()
+    tracing = TraceReceiver(store)
+    scope = {"team_ids": ["team-research"], "api_key_hash": ""}
+    assert await tracing.get_trace("t1", scope) is None  # type: ignore[arg-type]
+    store.get_trace.assert_awaited_once_with("t1", scope)
+    await tracing.flush()
+    store.flush.assert_awaited_once()