Feature/enhance huggingfacepipeline to handle different return type (#…

…11394)

**Description:** Avoid huggingfacepipeline to truncate the response if
user setup return_full_text as False within huggingface pipeline.

**Dependencies:** : None
**Tag maintainer:**   Maybe @sam-h-bean ?

---------

Co-authored-by: Bagatur <[email protected]>

libs/langchain/langchain/llms/huggingface_pipeline.py

@@ -202,8 +202,23 @@ def _generate(
                     response = response[0]
 
                 if self.pipeline.task == "text-generation":
-                    # Text generation return includes the starter text
-                    text = response["generated_text"][len(batch_prompts[j]) :]
+                    try:
+                        from transformers.pipelines.text_generation import ReturnType
+
+                        remove_prompt = (
+                            self.pipeline._postprocess_params.get("return_type")
+                            != ReturnType.NEW_TEXT
+                        )
+                    except Exception as e:
+                        logger.warning(
+                            f"Unable to extract pipeline return_type. "
+                            f"Received error:\n\n{e}"
+                        )
+                        remove_prompt = True
+                    if remove_prompt:
+                        text = response["generated_text"][len(batch_prompts[j]) :]
+                    else:
+                        text = response["generated_text"]
                 elif self.pipeline.task == "text2text-generation":
                     text = response["generated_text"]
                 elif self.pipeline.task == "summarization":