Test to verify that await model.astream(simple_message) works.
This should pass for all integrations. Passing this test does not indicate a "natively async" or "streaming" implementation, but rather that the model can be used in an async streaming context.
First, debug
langchain_tests.integration_tests.chat_models.ChatModelIntegrationTests.test_stream.
and
langchain_tests.integration_tests.chat_models.ChatModelIntegrationTests.test_ainvoke.
because astream has a default implementation that calls _stream in
an async context if it is implemented, or ainvoke and yields the result
as a single chunk if not.
If those tests pass but not this one, you should make sure your _astream
method does not raise any exceptions, and that it yields valid
langchain_core.outputs.chat_generation.ChatGenerationChunk
objects like so:
yield ChatGenerationChunk(message=AIMessageChunk(content="chunk text"))See test_stream troubleshooting for chunk_position requirements.
test_astream(
self,
model: BaseChatModel,
) -> None