multiple: langchain 0.2 in master (#21191)

0.2rc 

migrations

- [x] Move memory
- [x] Move remaining retrievers
- [x] graph_qa chains
- [x] some dependency from evaluation code potentially on math utils
- [x] Move openapi chain from `langchain.chains.api.openapi` to
`langchain_community.chains.openapi`
- [x] Migrate `langchain.chains.ernie_functions` to
`langchain_community.chains.ernie_functions`
- [x] migrate `langchain/chains/llm_requests.py` to
`langchain_community.chains.llm_requests`
- [x] Moving `langchain_community.cross_enoders.base:BaseCrossEncoder`
->
`langchain_community.retrievers.document_compressors.cross_encoder:BaseCrossEncoder`
(namespace not ideal, but it needs to be moved to `langchain` to avoid
circular deps)
- [x] unit tests langchain -- add pytest.mark.community to some unit
tests that will stay in langchain
- [x] unit tests community -- move unit tests that depend on community
to community
- [x] mv integration tests that depend on community to community
- [x] mypy checks

Other todo

- [x] Make deprecation warnings not noisy (need to use warn deprecated
and check that things are implemented properly)
- [x] Update deprecation messages with timeline for code removal (likely
we actually won't be removing things until 0.4 release) -- will give
people more time to transition their code.
- [ ] Add information to deprecation warning to show users how to
migrate their code base using langchain-cli
- [ ] Remove any unnecessary requirements in langchain (e.g., is
SQLALchemy required?)

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

libs/community/tests/unit_tests/agents/test_tools.py

@@ -0,0 +1,100 @@
+"""Test tool utils."""
+import unittest
+from typing import Any, Type
+from unittest.mock import MagicMock, Mock
+
+import pytest
+from langchain.agents.agent import Agent
+from langchain.agents.chat.base import ChatAgent
+from langchain.agents.conversational.base import ConversationalAgent
+from langchain.agents.conversational_chat.base import ConversationalChatAgent
+from langchain.agents.mrkl.base import ZeroShotAgent
+from langchain.agents.react.base import ReActDocstoreAgent, ReActTextWorldAgent
+from langchain.agents.self_ask_with_search.base import SelfAskWithSearchAgent
+from langchain_core.tools import Tool, ToolException, tool
+
+from langchain_community.agent_toolkits.load_tools import load_tools
+from tests.unit_tests.callbacks.fake_callback_handler import FakeCallbackHandler
+
+
+@pytest.mark.parametrize(
+    "agent_cls",
+    [
+        ZeroShotAgent,
+        ChatAgent,
+        ConversationalChatAgent,
+        ConversationalAgent,
+        ReActDocstoreAgent,
+        ReActTextWorldAgent,
+        SelfAskWithSearchAgent,
+    ],
+)
+def test_single_input_agent_raises_error_on_structured_tool(
+    agent_cls: Type[Agent],
+) -> None:
+    """Test that older agents raise errors on older tools."""
+
+    @tool
+    def the_tool(foo: str, bar: str) -> str:
+        """Return the concat of foo and bar."""
+        return foo + bar
+
+    with pytest.raises(
+        ValueError,
+        match=f"{agent_cls.__name__} does not support"  # type: ignore
+        f" multi-input tool {the_tool.name}.",
+    ):
+        agent_cls.from_llm_and_tools(MagicMock(), [the_tool])  # type: ignore
+
+
+def test_tool_no_args_specified_assumes_str() -> None:
+    """Older tools could assume *args and **kwargs were passed in."""
+
+    def ambiguous_function(*args: Any, **kwargs: Any) -> str:
+        """An ambiguously defined function."""
+        return args[0]
+
+    some_tool = Tool(
+        name="chain_run",
+        description="Run the chain",
+        func=ambiguous_function,
+    )
+    expected_args = {"tool_input": {"type": "string"}}
+    assert some_tool.args == expected_args
+    assert some_tool.run("foobar") == "foobar"
+    assert some_tool.run({"tool_input": "foobar"}) == "foobar"
+    with pytest.raises(ToolException, match="Too many arguments to single-input tool"):
+        some_tool.run({"tool_input": "foobar", "other_input": "bar"})
+
+
+def test_load_tools_with_callback_manager_raises_deprecation_warning() -> None:
+    """Test load_tools raises a deprecation for old callback manager kwarg."""
+    callback_manager = MagicMock()
+    with pytest.warns(DeprecationWarning, match="callback_manager is deprecated"):
+        tools = load_tools(
+            ["requests_get"],
+            callback_manager=callback_manager,
+            allow_dangerous_tools=True,
+        )
+    assert len(tools) == 1
+    assert tools[0].callbacks == callback_manager
+
+
+def test_load_tools_with_callbacks_is_called() -> None:
+    """Test callbacks are called when provided to load_tools fn."""
+    callbacks = [FakeCallbackHandler()]
+    tools = load_tools(
+        ["requests_get"],  # type: ignore
+        callbacks=callbacks,  # type: ignore
+        allow_dangerous_tools=True,
+    )
+    assert len(tools) == 1
+    # Patch the requests.get() method to return a mock response
+    with unittest.mock.patch(
+        "langchain.requests.TextRequestsWrapper.get",
+        return_value=Mock(text="Hello world!"),
+    ):
+        result = tools[0].run("https://www.google.com")
+        assert result.text == "Hello world!"
+    assert callbacks[0].tool_starts == 1
+    assert callbacks[0].tool_ends == 1