fix(integrations): make langchain package optional for LangchainIntegration

Author: mshavliuk

sentry_sdk/integrations/langchain.py

@@ -29,7 +29,6 @@
 
 
 try:
-    from langchain.agents import AgentExecutor
     from langchain_core.agents import AgentFinish
     from langchain_core.callbacks import (
         BaseCallbackHandler,
@@ -72,10 +71,13 @@ def __init__(self, include_prompts=True, max_spans=1024):
     def setup_once():
         # type: () -> None
         manager._configure = _wrap_configure(manager._configure)
+        try:
+            from langchain.agents import AgentExecutor
 
-        if AgentExecutor is not None:
             AgentExecutor.invoke = _wrap_agent_executor_invoke(AgentExecutor.invoke)
             AgentExecutor.stream = _wrap_agent_executor_stream(AgentExecutor.stream)
+        except ImportError:
+            pass
 
 
 class WatchedSpan:

tests/integrations/langchain/test_langchain.py

@@ -1,3 +1,5 @@
+import builtins
+import importlib
 from typing import List, Optional, Any, Iterator
 from unittest import mock
 from unittest.mock import Mock
@@ -382,6 +384,30 @@ def test_span_origin(sentry_init, capture_events):
         assert span["origin"] == "auto.ai.langchain"
 
 
+def test_langchain_module_is_optional():
+    """
+    Test that the LangchainIntegration can be imported and set up
+    even if the langchain module is not installed.
+    """
+
+    def hide_langchain(name, *args):
+        if name == "langchain" or name.startswith("langchain."):
+            raise ModuleNotFoundError("mocked: langchain not installed")
+        return mock.DEFAULT
+
+    integration_module = importlib.import_module(LangchainIntegration.__module__)
+
+    with (
+        mock.patch("sentry_sdk.integrations.langchain.manager"),
+        mock.patch.object(
+            builtins, "__import__", side_effect=hide_langchain
+        ) as mock_import,
+    ):
+        importlib.reload(integration_module)
+        LangchainIntegration().setup_once()
+        mock_import.assert_any_call("langchain.agents", *([mock.ANY] * 4))
+
+
 def test_manual_callback_no_duplication(sentry_init):
     """
     Test that when a user manually provides a SentryLangchainCallback,