cohere[patch]: Fix retriever (langchain-ai#19771)

* Replace `source_documents` with `documents`
* Pass `documents` as a named arg vs keyword
* Make `parsed_docs` more robust
* Fix edge case of doc page_content being `None`

libs/partners/cohere/langchain_cohere/chat_models.py

@@ -17,6 +17,7 @@
     AsyncCallbackManagerForLLMRun,
     CallbackManagerForLLMRun,
 )
+from langchain_core.documents import Document
 from langchain_core.language_models import LanguageModelInput
 from langchain_core.language_models.chat_models import (
     BaseChatModel,
@@ -73,7 +74,7 @@ def get_role(message: BaseMessage) -> str:
 def get_cohere_chat_request(
     messages: List[BaseMessage],
     *,
-    documents: Optional[List[Dict[str, str]]] = None,
+    documents: Optional[List[Document]] = None,
     connectors: Optional[List[Dict[str, str]]] = None,
     **kwargs: Any,
 ) -> Dict[str, Any]:
@@ -95,17 +96,25 @@ def get_cohere_chat_request(
             "Received documents both as a keyword argument and as an prompt additional keyword argument. Please choose only one option."  # noqa: E501
         )
 
+    parsed_docs: Optional[List[Document]] = None
+    if "documents" in additional_kwargs:
+        parsed_docs = (
+            additional_kwargs["documents"]
+            if len(additional_kwargs["documents"]) > 0
+            else None
+        )
+    elif documents is not None and len(documents) > 0:
+        parsed_docs = documents
+
     formatted_docs: Optional[List[Dict[str, Any]]] = None
-    if additional_kwargs.get("documents"):
+    if parsed_docs is not None:
         formatted_docs = [
             {
                 "text": doc.page_content,
                 "id": doc.metadata.get("id") or f"doc-{str(i)}",
             }
-            for i, doc in enumerate(additional_kwargs.get("documents", []))
+            for i, doc in enumerate(parsed_docs)
         ]
-    elif documents:
-        formatted_docs = documents
 
     # by enabling automatic prompt truncation, the probability of request failure is
     # reduced with minimal impact on response quality

libs/partners/cohere/langchain_cohere/rag_retrievers.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Any, Dict, List
+from typing import TYPE_CHECKING, Any, Dict, List, Optional
 
 from langchain_core.callbacks import (
     AsyncCallbackManagerForRetrieverRun,
@@ -17,15 +17,16 @@
 
 
 def _get_docs(response: Any) -> List[Document]:
-    docs = (
-        []
-        if "documents" not in response.generation_info
-        or len(response.generation_info["documents"]) == 0
-        else [
-            Document(page_content=doc["snippet"], metadata=doc)
-            for doc in response.generation_info["documents"]
-        ]
-    )
+    docs = []
+    if (
+        "documents" in response.generation_info
+        and len(response.generation_info["documents"]) > 0
+    ):
+        for doc in response.generation_info["documents"]:
+            content = doc.get("snippet", None) or doc.get("text", None)
+            if content is not None:
+                docs.append(Document(page_content=content, metadata=doc))
+
     docs.append(
         Document(
             page_content=response.message.content,
@@ -63,12 +64,18 @@ class Config:
         """Allow arbitrary types."""
 
     def _get_relevant_documents(
-        self, query: str, *, run_manager: CallbackManagerForRetrieverRun, **kwargs: Any
+        self,
+        query: str,
+        *,
+        run_manager: CallbackManagerForRetrieverRun,
+        documents: Optional[List[Dict[str, str]]] = None,
+        **kwargs: Any,
     ) -> List[Document]:
         messages: List[List[BaseMessage]] = [[HumanMessage(content=query)]]
         res = self.llm.generate(
             messages,
-            connectors=self.connectors,
+            connectors=self.connectors if documents is None else None,
+            documents=documents,
             callbacks=run_manager.get_child(),
             **kwargs,
         ).generations[0][0]
@@ -79,13 +86,15 @@ async def _aget_relevant_documents(
         query: str,
         *,
         run_manager: AsyncCallbackManagerForRetrieverRun,
+        documents: Optional[List[Dict[str, str]]] = None,
         **kwargs: Any,
     ) -> List[Document]:
         messages: List[List[BaseMessage]] = [[HumanMessage(content=query)]]
         res = (
             await self.llm.agenerate(
                 messages,
-                connectors=self.connectors,
+                connectors=self.connectors if documents is None else None,
+                documents=documents,
                 callbacks=run_manager.get_child(),
                 **kwargs,
             )