test_astream_events_from_model() — langchain Function Reference

Architecture documentation for the test_astream_events_from_model() function in test_runnable_events_v2.py from the langchain codebase.

Function python LangChainCore Runnables calls 1

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LangChainCore→ Runnables→ test_astream_events_from_model() — langchain Function Reference

Dependency Diagram

graph TD
  e7e77e50_7157_85f1_ee50_798036a3da6b["test_astream_events_from_model()"]
  33c02978_2077_5819_7048_bc2a81e80625["test_runnable_events_v2.py"]
  e7e77e50_7157_85f1_ee50_798036a3da6b -->|defined in| 33c02978_2077_5819_7048_bc2a81e80625
  716d2a5e_dc8e_3cae_e044_b56b06bee655["_collect_events()"]
  e7e77e50_7157_85f1_ee50_798036a3da6b -->|calls| 716d2a5e_dc8e_3cae_e044_b56b06bee655
  style e7e77e50_7157_85f1_ee50_798036a3da6b fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/tests/unit_tests/runnables/test_runnable_events_v2.py lines 506–603

async def test_astream_events_from_model() -> None:
    """Test the output of a model."""
    infinite_cycle = cycle([AIMessage(content="hello world!")])
    # When streaming GenericFakeChatModel breaks AIMessage into chunks based on spaces
    model = (
        GenericFakeChatModel(messages=infinite_cycle)
        .with_config(
            {
                "metadata": {"a": "b"},
                "tags": ["my_model"],
                "run_name": "my_model",
            }
        )
        .bind(stop="<stop_token>")
    )
    events = await _collect_events(model.astream_events("hello", version="v2"))
    _assert_events_equal_allow_superset_metadata(
        events,
        [
            {
                "data": {"input": "hello"},
                "event": "on_chat_model_start",
                "metadata": {
                    "a": "b",
                    "ls_model_type": "chat",
                    "ls_stop": "<stop_token>",
                },
                "name": "my_model",
                "run_id": "",
                "parent_ids": [],
                "tags": ["my_model"],
            },
            {
                "data": {
                    "chunk": _any_id_ai_message_chunk(
                        content="hello",
                    )
                },
                "event": "on_chat_model_stream",
                "metadata": {
                    "a": "b",
                    "ls_model_type": "chat",
                    "ls_stop": "<stop_token>",
                },
                "name": "my_model",
                "run_id": "",
                "parent_ids": [],
                "tags": ["my_model"],
            },
            {
                "data": {"chunk": _any_id_ai_message_chunk(content=" ")},
                "event": "on_chat_model_stream",
                "metadata": {
                    "a": "b",
                    "ls_model_type": "chat",
                    "ls_stop": "<stop_token>",
                },
                "name": "my_model",
                "run_id": "",
                "parent_ids": [],
                "tags": ["my_model"],
            },
            {
                "data": {
                    "chunk": _any_id_ai_message_chunk(
                        content="world!", chunk_position="last"
                    )
                },
                "event": "on_chat_model_stream",
                "metadata": {
                    "a": "b",
                    "ls_model_type": "chat",
                    "ls_stop": "<stop_token>",
                },
                "name": "my_model",
                "run_id": "",
                "parent_ids": [],
                "tags": ["my_model"],
            },
            {
                "data": {