From b65a9414bb9b549f54f7ce917d56879fea9c2fdb Mon Sep 17 00:00:00 2001
From: Nuno Campos <nuno@boringbits.io>
Date: Sat, 29 Jul 2023 23:48:30 +0100
Subject: [PATCH] runnable.bind().bind() should combine kwargs, instead of
 nesting wrappers (#8467)

<!-- Thank you for contributing to LangChain!

Replace this comment with:
  - Description: a description of the change,
  - Issue: the issue # it fixes (if applicable),
  - Dependencies: any dependencies required for this change,
- Tag maintainer: for a quicker response, tag the relevant maintainer
(see below),
- Twitter handle: we announce bigger features on Twitter. If your PR
gets announced and you'd like a mention, we'll gladly shout you out!

Please make sure you're PR is passing linting and testing before
submitting. Run `make format`, `make lint` and `make test` to check this
locally.

If you're adding a new integration, please include:
1. a test for the integration, preferably unit tests that do not rely on
network access,
  2. an example notebook showing its use.

Maintainer responsibilities:
  - General / Misc / if you don't know who to tag: @baskaryan
  - DataLoaders / VectorStores / Retrievers: @rlancemartin, @eyurtsev
  - Models / Prompts: @hwchase17, @baskaryan
  - Memory: @hwchase17
  - Agents / Tools / Toolkits: @hinthornw
  - Tracing / Callbacks: @agola11
  - Async: @agola11

If no one reviews your PR within a few days, feel free to @-mention the
same people again.

See contribution guidelines for more information on how to write/run
tests, lint, etc:
https://github.com/hwchase17/langchain/blob/master/.github/CONTRIBUTING.md
 -->

---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>
---
 libs/langchain/langchain/schema/runnable.py          |  3 +++
 .../tests/unit_tests/schema/test_runnable.py         | 12 +++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/libs/langchain/langchain/schema/runnable.py b/libs/langchain/langchain/schema/runnable.py
index 0864fe55d0..09f76de492 100644
--- a/libs/langchain/langchain/schema/runnable.py
+++ b/libs/langchain/langchain/schema/runnable.py
@@ -714,6 +714,9 @@ class RunnableBinding(Serializable, Runnable[Input, Output]):
     def lc_serializable(self) -> bool:
         return True
 
+    def bind(self, **kwargs: Any) -> Runnable[Input, Output]:
+        return self.__class__(bound=self.bound, kwargs={**self.kwargs, **kwargs})
+
     def invoke(self, input: Input, config: Optional[RunnableConfig] = None) -> Output:
         return self.bound.invoke(input, config, **self.kwargs)
 
diff --git a/libs/langchain/tests/unit_tests/schema/test_runnable.py b/libs/langchain/tests/unit_tests/schema/test_runnable.py
index 23fda63f45..02104e8b4b 100644
--- a/libs/langchain/tests/unit_tests/schema/test_runnable.py
+++ b/libs/langchain/tests/unit_tests/schema/test_runnable.py
@@ -11,7 +11,7 @@ from langchain.callbacks.tracers.base import BaseTracer
 from langchain.callbacks.tracers.schemas import Run
 from langchain.chat_models.fake import FakeListChatModel
 from langchain.llms.fake import FakeListLLM
-from langchain.load.dump import dumps
+from langchain.load.dump import dumpd, dumps
 from langchain.output_parsers.list import CommaSeparatedListOutputParser
 from langchain.prompts.chat import (
     ChatPromptTemplate,
@@ -609,3 +609,13 @@ def test_seq_prompt_map(
         ]
     )
     assert tracer.runs == snapshot
+
+
+def test_bind_bind() -> None:
+    llm = FakeListLLM(responses=["i'm a textbot"])
+
+    assert dumpd(
+        llm.bind(stop=["Thought:"], one="two").bind(
+            stop=["Observation:"], hello="world"
+        )
+    ) == dumpd(llm.bind(stop=["Observation:"], one="two", hello="world"))