Fix getattr in runnable binding for cases where config is passed in as arg too (#20528)

…s arg too

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libs/core/langchain_core/runnables/base.py

@@ -4895,17 +4895,39 @@ class RunnableBinding(RunnableBindingBase[Input, Output]):
     def __getattr__(self, name: str) -> Any:
         attr = getattr(self.bound, name)
 
-        if callable(attr) and accepts_config(attr):
+        if callable(attr) and (
+            config_param := inspect.signature(attr).parameters.get("config")
+        ):
+            if config_param.kind == inspect.Parameter.KEYWORD_ONLY:
 
-            @wraps(attr)
-            def wrapper(*args: Any, **kwargs: Any) -> Any:
-                return attr(
-                    *args,
-                    **kwargs,
-                    config=merge_configs(self.config, kwargs.get("config")),
-                )
+                @wraps(attr)
+                def wrapper(*args: Any, **kwargs: Any) -> Any:
+                    return attr(
+                        *args,
+                        config=merge_configs(self.config, kwargs.pop("config", None)),
+                        **kwargs,
+                    )
 
-            return wrapper
+                return wrapper
+            elif config_param.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
+                idx = list(inspect.signature(attr).parameters).index("config")
+
+                @wraps(attr)
+                def wrapper(*args: Any, **kwargs: Any) -> Any:
+                    if len(args) >= idx + 1:
+                        argsl = list(args)
+                        argsl[idx] = merge_configs(self.config, argsl[idx])
+                        return attr(*argsl, **kwargs)
+                    else:
+                        return attr(
+                            *args,
+                            config=merge_configs(
+                                self.config, kwargs.pop("config", None)
+                            ),
+                            **kwargs,
+                        )
+
+                return wrapper
 
         return attr
 

libs/core/langchain_core/runnables/graph.py

@@ -344,6 +344,7 @@ class Graph:
 
     def draw_mermaid(
         self,
+        *,
         curve_style: CurveStyle = CurveStyle.LINEAR,
         node_colors: NodeColors = NodeColors(
             start="#ffdfba", end="#baffc9", other="#fad7de"
@@ -372,6 +373,7 @@ class Graph:
 
     def draw_mermaid_png(
         self,
+        *,
         curve_style: CurveStyle = CurveStyle.LINEAR,
         node_colors: NodeColors = NodeColors(
             start="#ffdfba", end="#baffc9", other="#fad7de"

libs/core/langchain_core/runnables/graph_mermaid.py

@@ -14,6 +14,7 @@ from langchain_core.runnables.graph import (
 def draw_mermaid(
     nodes: Dict[str, str],
     edges: List[Edge],
+    *,
     first_node_label: Optional[str] = None,
     last_node_label: Optional[str] = None,
     curve_style: CurveStyle = CurveStyle.LINEAR,