ref(langchain): Greatly simplify _wrap_configure (#4479)

Resolving #4443 requires some changes to this method, but the current
`args`/`kwargs` business makes the method difficult to reason through.

This PR simplifies the logic by listing out the parameters we need to
access, so we don't need to access them through `args` and `kwargs`.

We also cut down on the amount of branching and the amount of variables
(`new_callbacks` vs `existing_callbacks`).

Behavior does not change in this PR; we fix the #4443 bug in #4485,
which is based on this PR
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Author: szokeasaurusrex

sentry_sdk/integrations/langchain.py

@@ -22,6 +22,7 @@
     from langchain_core.callbacks import (
         manager,
         BaseCallbackHandler,
+        Callbacks,
     )
     from langchain_core.agents import AgentAction, AgentFinish
 except ImportError:
@@ -416,50 +417,57 @@ def _wrap_configure(f):
     # type: (Callable[..., Any]) -> Callable[..., Any]
 
     @wraps(f)
-    def new_configure(*args, **kwargs):
-        # type: (Any, Any) -> Any
+    def new_configure(
+        callback_manager_cls,  # type: type
+        inheritable_callbacks=None,  # type: Callbacks
+        local_callbacks=None,  # type: Callbacks
+        *args,  # type: Any
+        **kwargs,  # type: Any
+    ):
+        # type: (...) -> Any
 
         integration = sentry_sdk.get_client().get_integration(LangchainIntegration)
         if integration is None:
-            return f(*args, **kwargs)
+            return f(
+                callback_manager_cls,
+                inheritable_callbacks,
+                local_callbacks,
+                *args,
+                **kwargs,
+            )
 
-        with capture_internal_exceptions():
-            new_callbacks = []  # type: List[BaseCallbackHandler]
-            if "local_callbacks" in kwargs:
-                existing_callbacks = kwargs["local_callbacks"]
-                kwargs["local_callbacks"] = new_callbacks
-            elif len(args) > 2:
-                existing_callbacks = args[2]
-                args = (
-                    args[0],
-                    args[1],
-                    new_callbacks,
-                ) + args[3:]
-            else:
-                existing_callbacks = []
-
-            if existing_callbacks:
-                if isinstance(existing_callbacks, list):
-                    for cb in existing_callbacks:
-                        new_callbacks.append(cb)
-                elif isinstance(existing_callbacks, BaseCallbackHandler):
-                    new_callbacks.append(existing_callbacks)
-                else:
-                    logger.debug("Unknown callback type: %s", existing_callbacks)
-
-            already_added = False
-            for callback in new_callbacks:
-                if isinstance(callback, SentryLangchainCallback):
-                    already_added = True
-
-            if not already_added:
-                new_callbacks.append(
-                    SentryLangchainCallback(
-                        integration.max_spans,
-                        integration.include_prompts,
-                        integration.tiktoken_encoding_name,
-                    )
-                )
-        return f(*args, **kwargs)
+        callbacks_list = local_callbacks or []
+
+        if isinstance(callbacks_list, BaseCallbackHandler):
+            callbacks_list = [callbacks_list]
+        elif not isinstance(callbacks_list, list):
+            logger.debug("Unknown callback type: %s", callbacks_list)
+            # Just proceed with original function call
+            return f(
+                callback_manager_cls,
+                inheritable_callbacks,
+                local_callbacks,
+                *args,
+                **kwargs,
+            )
+
+        if not any(isinstance(cb, SentryLangchainCallback) for cb in callbacks_list):
+            # Avoid mutating the existing callbacks list
+            callbacks_list = [
+                *callbacks_list,
+                SentryLangchainCallback(
+                    integration.max_spans,
+                    integration.include_prompts,
+                    integration.tiktoken_encoding_name,
+                ),
+            ]
+
+        return f(
+            callback_manager_cls,
+            inheritable_callbacks,
+            callbacks_list,
+            *args,
+            **kwargs,
+        )
 
     return new_configure