fix: check dependency close method (#5082) (#5084)

* fix: check dependency close method

* import annotations

* return string only

---------

Co-authored-by: YuXuan Tay <tay.yuxuan@gt.tech.gov.sg>

src/_bentoml_sdk/service/dependency.py

@@ -103,7 +103,10 @@ def __getattr__(self, name: str) -> t.Any:
     async def close(self) -> None:
         if self._resolved is None:
             return
-        await t.cast("RemoteProxy[t.Any]", self._resolved).close()
+
+        remote_proxy = t.cast("RemoteProxy[t.Any]", self._resolved)
+        if asyncio.iscoroutinefunction(getattr(remote_proxy, "close", None)):
+            await remote_proxy.close()
 
 
 @t.overload

tests/e2e/bento_new_sdk/test_asgi.py

@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+from starlette.testclient import TestClient
+
+import bentoml
+
+
+@bentoml.service(metrics={"enabled": False})
+class Model:
+    model = {"hello": "world"}
+
+    @bentoml.api()
+    def get(self, key: str) -> str:
+        return self.model.get(key, "")
+
+
+@bentoml.service(metrics={"enabled": False})
+class Service:
+    model = bentoml.depends(Model)
+
+    @bentoml.api()
+    def get(self, key: str) -> dict[str, str]:
+        return {"value": self.model.get(key)}
+
+
+def test_simple_service():
+    with TestClient(app=Model.to_asgi()) as client:
+        resp = client.post("/get", json={"key": "hello"})
+
+        assert resp.status_code == 200
+        assert resp.text == "world"
+
+
+def test_composed_service():
+    with TestClient(app=Service.to_asgi()) as client:
+        resp = client.post("/get", json={"key": "hello"})
+
+        assert resp.status_code == 200
+        assert resp.json() == {"value": "world"}