standard-tests[patch]: add async test for structured output (#26527)

libs/standard-tests/langchain_standard_tests/integration_tests/chat_models.py

@@ -44,6 +44,13 @@ def magic_function_no_args() -> int:
     return 5
 
 
+class Joke(BaseModel):
+    """Joke to tell user."""
+
+    setup: str = Field(description="question to set up a joke")
+    punchline: str = Field(description="answer to resolve the joke")
+
+
 def _validate_tool_call_message(message: BaseMessage) -> None:
     assert isinstance(message, AIMessage)
     assert len(message.tool_calls) == 1
@@ -240,12 +247,6 @@ class ChatModelIntegrationTests(ChatModelTests):
         if not self.has_tool_calling:
             pytest.skip("Test requires tool calling.")
 
-        class Joke(BaseModel):
-            """Joke to tell user."""
-
-            setup: str = Field(description="question to set up a joke")
-            punchline: str = Field(description="answer to resolve the joke")
-
         # Pydantic class
         # Type ignoring since the interface only officially supports pydantic 1
         # or pydantic.v1.BaseModel but not pydantic.BaseModel from pydantic 2.
@@ -268,6 +269,33 @@ class ChatModelIntegrationTests(ChatModelTests):
         assert isinstance(chunk, dict)  # for mypy
         assert set(chunk.keys()) == {"setup", "punchline"}
 
+    async def test_structured_output_async(self, model: BaseChatModel) -> None:
+        """Test to verify structured output with a Pydantic model."""
+        if not self.has_tool_calling:
+            pytest.skip("Test requires tool calling.")
+
+        # Pydantic class
+        # Type ignoring since the interface only officially supports pydantic 1
+        # or pydantic.v1.BaseModel but not pydantic.BaseModel from pydantic 2.
+        # We'll need to do a pass updating the type signatures.
+        chat = model.with_structured_output(Joke)  # type: ignore[arg-type]
+        result = await chat.ainvoke("Tell me a joke about cats.")
+        assert isinstance(result, Joke)
+
+        async for chunk in chat.astream("Tell me a joke about cats."):
+            assert isinstance(chunk, Joke)
+
+        # Schema
+        chat = model.with_structured_output(Joke.model_json_schema())
+        result = await chat.ainvoke("Tell me a joke about cats.")
+        assert isinstance(result, dict)
+        assert set(result.keys()) == {"setup", "punchline"}
+
+        async for chunk in chat.astream("Tell me a joke about cats."):
+            assert isinstance(chunk, dict)
+        assert isinstance(chunk, dict)  # for mypy
+        assert set(chunk.keys()) == {"setup", "punchline"}
+
     @pytest.mark.skipif(PYDANTIC_MAJOR_VERSION != 2, reason="Test requires pydantic 2.")
     def test_structured_output_pydantic_2_v1(self, model: BaseChatModel) -> None:
         """Test to verify compatibility with pydantic.v1.BaseModel.