test: verify sampling parameters through the full governance stack

src/polygateway/middleware/telemetry.py

@@ -29,7 +29,7 @@ if TYPE_CHECKING:
 
 
 class TelemetryEmitter:
-    """从请求与结果组装 20 字段并写入 recorder;一切写失败降级 warning。"""
+    """从请求与结果组装 21 字段并写入 recorder;一切写失败降级 warning。"""
 
     def __init__(self, recorder: TelemetryRecorder, *, pricing: PricingTable | None = None) -> None:
         self._recorder = recorder
@@ -65,9 +65,7 @@ class TelemetryEmitter:
             cached_prompt_tokens=response.cached_prompt_tokens if response else None,
             model_reported=response.model_reported if response else None,
             # 唯一有"生效源"的入口,故是唯一能并上 extra_body 的(设计决策 D)
-            sampling=canonical_sampling_json(
+            sampling=canonical_sampling_json(merge_sampling(source.extra_body, request.sampling)),
-                merge_sampling(source.extra_body, request.sampling)
-            ),
         )
 
     async def emit_cache_hit(self, *, request: ChatRequest, response: LLMResponse) -> None:

src/polygateway/types.py

@@ -59,9 +59,7 @@ def validate_request_overlay(overlay: Mapping[str, Any], *, origin: str) -> dict
     return dict(overlay)
 
 
-def merge_sampling(
+def merge_sampling(extra_body: Mapping[str, Any], sampling: Mapping[str, Any]) -> dict[str, Any]:
-    extra_body: Mapping[str, Any], sampling: Mapping[str, Any]
-) -> dict[str, Any]:
     """合并配置级与调用级采样参数;调用级优先(issue #4 设计决策 A)。"""
     return {**extra_body, **sampling}
 
@@ -237,9 +235,7 @@ class SourceConfig:
         object.__setattr__(self, "extra_body", MappingProxyType(validated))
 
 
-def strip_unsupported_extra_body(
+def strip_unsupported_extra_body(sources: list[SourceConfig], *, path: str) -> list[SourceConfig]:
-    sources: list[SourceConfig], *, path: str
-) -> list[SourceConfig]:
     """剥离非 chat 路径不消费的 `extra_body` 并 warning(issue #4 决策 G)。
 
     剥离是必需的而非顺手清理: embedding 的 payload 硬编码 `{model, input}`、

tests/integration/test_governance_stack.py

@@ -4,6 +4,7 @@
 """
 
 import asyncio
+import dataclasses
 import json
 import sqlite3
 
@@ -204,3 +205,74 @@ class TestTransientErrorExport:
 
         assert isinstance(ei.value, polygateway.AllSourcesExhausted)
         assert isinstance(ei.value.__cause__, TransientError)
+
+
+class TestSamplingThroughStack:
+    """issue #4: 采样参数经完整洋葱到达请求体,且缓存/遥测口径一致。"""
+
+    async def test_reaches_wire_and_lands_in_telemetry(self, tmp_path):
+        seen = []
+
+        def handler(request):
+            seen.append(json.loads(request.content))
+            return _sse()
+
+        db = tmp_path / "t.db"
+        recorder = SQLiteRecorder(db)
+        client = _full_client(handler, telemetry=recorder)
+        await client.chat([{"role": "user", "content": "hi"}], overlay={"seed": 42})
+        recorder.close()
+
+        assert seen[0]["seed"] == 42  # 穿过全栈到达线上
+        rows = sqlite3.connect(db).execute("SELECT sampling FROM llm_calls").fetchall()
+        assert json.loads(rows[0][0]) == {"seed": 42}
+
+    async def test_config_level_merges_and_records(self, tmp_path):
+        """源级 extra_body 只有 emit_attempt 记得到(唯一有生效源的入口)。"""
+        seen = []
+
+        def handler(request):
+            seen.append(json.loads(request.content))
+            return _sse()
+
+        src = dataclasses.replace(_source(), extra_body={"temperature": 0})
+        db = tmp_path / "t.db"
+        recorder = SQLiteRecorder(db)
+        client = GatewayClient(
+            scope="llm",
+            sources=[src],
+            selector=RoundRobinSelector(),
+            limiter=InMemoryLimiter(
+                scope="llm", sources={src.name: src}, global_limits=GlobalLimits(0, 0, 0)
+            ),
+            breaker=InMemoryGate(config=_BREAKER),
+            transport=OpenAICompatTransport(
+                client_factory=lambda s: httpx.AsyncClient(transport=httpx.MockTransport(handler))
+            ),
+            retry=RetryPolicy(2, 2.0, 30.0),
+            backpressure=BackpressurePolicy(300.0, 0.01),
+            telemetry=recorder,
+            structured_strategy=JsonRepairStrategy(),
+            sleep=_noop_sleep,
+        )
+        await client.chat([{"role": "user", "content": "hi"}], overlay={"seed": 1})
+        recorder.close()
+
+        assert seen[0]["temperature"] == 0 and seen[0]["seed"] == 1
+        rows = sqlite3.connect(db).execute("SELECT sampling FROM llm_calls").fetchall()
+        assert json.loads(rows[0][0]) == {"seed": 1, "temperature": 0}
+
+    async def test_differing_seed_bypasses_cache_end_to_end(self):
+        """issue 场景全栈回归: 逐 rollout 变 seed 必须真的回源。"""
+        calls = []
+
+        def handler(request):
+            calls.append(json.loads(request.content)["seed"])
+            return _sse()
+
+        client = _full_client(handler, cache=InMemoryCache())
+        await client.chat([{"role": "user", "content": "hi"}], overlay={"seed": 1})
+        await client.chat([{"role": "user", "content": "hi"}], overlay={"seed": 2})
+        second_same = await client.chat([{"role": "user", "content": "hi"}], overlay={"seed": 1})
+        assert calls == [1, 2]  # 两个不同 seed 各自回源
+        assert second_same.cache_hit is True  # 同 seed 才命中

tests/unit/test_embedding.py

@@ -381,9 +381,7 @@ class TestExtraBodyStripped:
         会显示这次调用带了 temperature=0——那是数据造假,比参数失效更坏。
         """
         rec = _MemoryRecorder()
-        client, _ = _embed_client(
+        client, _ = _embed_client([_src(extra_body={"temperature": 0})], ["ok"], telemetry=rec)
-            [_src(extra_body={"temperature": 0})], ["ok"], telemetry=rec
-        )
         await client.embed(["hi"])
         assert rec.rows[0]["sampling"] is None
 

tests/unit/test_ocr_client.py

@@ -394,9 +394,7 @@ class TestExtraBodyStripped:
     async def test_telemetry_never_records_a_parameter_that_was_not_sent(self):
         """不剥离则审计表会显示这次 OCR 带了 temperature=0——数据造假。"""
         recorder = _MemoryRecorder()
-        client, _, _ = _client(
+        client, _, _ = _client([_src(extra_body={"temperature": 0})], ["text"], telemetry=recorder)
-            [_src(extra_body={"temperature": 0})], ["text"], telemetry=recorder
-        )
         await client.recognize_text(b"IMG")
         assert recorder.rows[0]["sampling"] is None