[Bugfix] Streamed tool calls now more strictly follow OpenAI's format; ensures Vercel AI SDK compatibility (#8272)

vllm/entrypoints/openai/tool_parsers/hermes_tool_parser.py

@@ -8,14 +8,14 @@ from partial_json_parser.core.options import Allow
 from vllm.entrypoints.openai.protocol import (DeltaFunctionCall, DeltaMessage,
                                               DeltaToolCall,
                                               ExtractedToolCallInformation,
-                                              FunctionCall,
-                                              InitialDeltaToolCall, ToolCall)
+                                              FunctionCall, ToolCall)
 from vllm.entrypoints.openai.tool_parsers.abstract_tool_parser import (
     ToolParser)
 from vllm.entrypoints.openai.tool_parsers.utils import (
     extract_intermediate_diff)
 from vllm.logger import init_logger
 from vllm.transformers_utils.tokenizer import AnyTokenizer, MistralTokenizer
+from vllm.utils import random_uuid
 
 logger = init_logger(__name__)
 
@@ -34,7 +34,6 @@ class Hermes2ProToolParser(ToolParser):
         self.prev_tool_call_arr: List[Dict] = []
         self.current_tool_id: int = -1
         self.current_tool_name_sent = False
-        self.current_tool_initial_sent: bool = False
         self.streamed_args_for_tool: List[str] = [
         ]  # map what has been streamed for each tool so far to a list
 
@@ -168,7 +167,6 @@ class Hermes2ProToolParser(ToolParser):
                 # set cursors and state appropriately
                 self.current_tool_id += 1
                 self.current_tool_name_sent = False
-                self.current_tool_initial_sent = False
                 self.streamed_args_for_tool.append("")
                 logger.debug("Starting on a new tool %s", self.current_tool_id)
 
@@ -218,24 +216,16 @@ class Hermes2ProToolParser(ToolParser):
                 logger.debug('not enough tokens to parse into JSON yet')
                 return None
 
-            # case - we haven't sent the initial delta with the tool call ID
-            #   (it will be sent)
-            if not self.current_tool_initial_sent:
-                self.current_tool_initial_sent = True
-                return DeltaMessage(tool_calls=[
-                    InitialDeltaToolCall(
-                        index=self.current_tool_id).model_dump(
-                            exclude_none=True)
-                ])
-
             # case - we haven't sent the tool name yet. If it's available, send
             #   it. otherwise, wait until it's available.
-            elif not self.current_tool_name_sent:
+            if not self.current_tool_name_sent:
                 function_name: Union[str, None] = current_tool_call.get("name")
                 if function_name:
                     self.current_tool_name_sent = True
                     return DeltaMessage(tool_calls=[
                         DeltaToolCall(index=self.current_tool_id,
+                                      type="function",
+                                      id=f"chatcmpl-tool-{random_uuid()}",
                                       function=DeltaFunctionCall(
                                           name=function_name).model_dump(
                                               exclude_none=True))