test(proxy): drop the restating docstrings and the request_body rebinding

The test names already say what each case covers, and the collect helper now builds the opted-in body inline instead of reassigning its parameter.

tests/test_litellm/proxy/pass_through_endpoints/test_streaming_handler_interrupt.py

@@ -398,20 +398,16 @@ def _openai_passthrough_stream_chunks():
     ]
 
 
+def _openai_opted_in_body():
+    return {"model": "gpt-4o-mini", "stream": True, "stream_options": {"include_usage": True}}
+
+
 async def _collect_openai_passthrough_chunks(chunks, endpoint_type, request_body=None):
-    # Default to the opt-in body a real caller must send for the OpenAI protocol
-    # to emit a usage frame at all -- cost injection is gated on that opt-in.
-    if request_body is None:
-        request_body = {
-            "model": "gpt-4o-mini",
-            "stream": True,
-            "stream_options": {"include_usage": True},
-        }
     response = _make_streaming_response(chunks)
     received = []
     async for chunk in PassThroughStreamingHandler.chunk_processor(
         response=response,
-        request_body=request_body,
+        request_body=_openai_opted_in_body() if request_body is None else request_body,
         litellm_logging_obj=_unarmed_logging_obj(),
         endpoint_type=endpoint_type,
         start_time=datetime.now(),
@@ -491,10 +487,6 @@ async def test_chunk_processor_streams_crlf_delimited_frames_live_and_injects_co
 
 @pytest.mark.asyncio
 async def test_chunk_processor_skips_injection_when_openai_caller_did_not_opt_in(monkeypatch):
-    """Regression: issue #38348 -- ``include_cost_in_streaming_usage`` is a process-wide
-    flag, but OpenAI-protocol callers opt into usage reporting per request via
-    ``stream_options.include_usage``. A caller that never asked for usage must not have
-    ``usage.cost`` injected into its stream just because the flag is on proxy-wide."""
     monkeypatch.setattr(litellm, "include_cost_in_streaming_usage", True)
     chunks = _openai_passthrough_stream_chunks()
 
@@ -509,8 +501,6 @@ async def test_chunk_processor_skips_injection_when_openai_caller_did_not_opt_in
 
 @pytest.mark.asyncio
 async def test_chunk_processor_respects_explicit_include_usage_false(monkeypatch):
-    """Regression: issue #38348 -- an explicit ``include_usage: false`` is a caller
-    opting out, and must be honoured even with the global flag on."""
     monkeypatch.setattr(litellm, "include_cost_in_streaming_usage", True)
     chunks = _openai_passthrough_stream_chunks()
 
@@ -529,9 +519,6 @@ async def test_chunk_processor_respects_explicit_include_usage_false(monkeypatch
 
 @pytest.mark.asyncio
 async def test_chunk_processor_anthropic_injects_without_stream_options(monkeypatch):
-    """The Anthropic Messages protocol has no ``stream_options`` for a caller to opt in
-    with, so injection stays always-on there while the flag is set -- issue #38348 asks
-    for that behaviour to be explicit rather than accidental."""
     monkeypatch.setattr(litellm, "include_cost_in_streaming_usage", True)
     frame = (
         b'data: {"type":"message_delta","delta":{"stop_reason":"end_turn"},'
@@ -559,8 +546,6 @@ async def test_chunk_processor_anthropic_injects_without_stream_options(monkeypa
 
 @pytest.mark.asyncio
 async def test_chunk_processor_anthropic_respects_explicit_opt_out(monkeypatch):
-    """Even on Anthropic, a caller that explicitly sends ``include_usage: false`` opts
-    out of cost injection."""
     monkeypatch.setattr(litellm, "include_cost_in_streaming_usage", True)
     frame = (
         b'data: {"type":"message_delta","delta":{"stop_reason":"end_turn"},'

tests/test_litellm/proxy/test_common_request_processing.py

@@ -10229,9 +10229,7 @@ class TestStreamingContainerOwnershipRecordedBeforeDone:
 
 
 class TestShouldInjectCostForRequest:
-    """Issue #38348: ``include_cost_in_streaming_usage`` is a process-wide flag, so on its
-    own it injects ``usage.cost`` for every caller on every route. Injection must also
-    consult the caller's per-request ``stream_options.include_usage`` opt-in."""
+    """Issue #38348: cost injection honours the caller's stream_options.include_usage."""
 
     def test_global_flag_off_never_injects(self, monkeypatch):
         monkeypatch.setattr(litellm, "include_cost_in_streaming_usage", False)
@@ -10274,8 +10272,6 @@ class TestShouldInjectCostForRequest:
         )
 
     def test_protocol_without_stream_options_stays_always_on(self, monkeypatch):
-        """Anthropic Messages / Vertex rawPredict / Gemini give a caller no way to opt
-        in, so the flag remains always-on there."""
         monkeypatch.setattr(litellm, "include_cost_in_streaming_usage", True)
         assert (
             ProxyBaseLLMRequestProcessing.should_inject_cost_for_request(
@@ -10307,10 +10303,6 @@ class TestShouldInjectCostForRequest:
 
 
 class TestProcessChunkCostInjectionGate:
-    """``_process_chunk_with_cost_injection`` takes the per-stream decision from
-    ``should_inject_cost_for_request`` and falls back to the global flag when the
-    caller does not pass one."""
-
     @staticmethod
     def _usage_chunk():
         return {