Ensuring function name is sent in a single chunk

Signed-off-by: avigny <[email protected]>

Author: avigny

tests/tool_use/test_mistral_tool_parser.py

@@ -306,7 +306,6 @@ def _test_extract_tool_calls_streaming(tool_parser, tokenizer, model_output,
             if tool_call.index != tool_call_idx:
                 tool_call_idx = tool_call.index
                 function_args_strs.append("")
-                function_names.append("")
                 tool_call_ids.append(None)
 
             # if a tool call ID is streamed, make sure one hasn't been already
@@ -319,7 +318,7 @@ def _test_extract_tool_calls_streaming(tool_parser, tokenizer, model_output,
                 # IN ENTIRETY, exactly one time.
                 if tool_call.function.name:
                     assert isinstance(tool_call.function.name, str)
-                    function_names[tool_call.index] += tool_call.function.name
+                    function_names.append(tool_call.function.name)
 
                 if tool_call.function.arguments:
                     # make sure they're a string and then add them to the list

vllm/entrypoints/openai/tool_parsers/mistral_tool_parser.py

@@ -261,24 +261,27 @@ def _generate_delta_tool_call(self,
             self.streaming_state = StreamingState.PARSING_NAME
             delta_text = delta_text.replace(self.bot_token, "", 1)
         if self.streaming_state == StreamingState.PARSING_NAME:
+            if self.current_tool_name is None:
+                    self.current_tool_name = ""
             # The name stops where the arguments start
             # And the arguments start with the `{` char
             if "{" in delta_text:
                 delta_function_name = delta_text.split("{")[0]
+                self.current_tool_name += delta_function_name
                 delta_text = delta_text[len(delta_function_name):]
                 self.streaming_state = StreamingState.PARSING_ARGUMENTS
             else:
-                delta_function_name = delta_text
-                return [
-                    DeltaToolCall(
+                # we want to send the tool name once it's complete
+                self.current_tool_name += delta_text
+                if tool_id is not None:
+                    return [
+                        DeltaToolCall(
                         index=self.current_tool_id,
                         type="function",
-                        id=tool_id,
-                        function=DeltaFunctionCall(
-                            name=delta_function_name).model_dump(
-                                exclude_none=True),
-                    )
-                ]
+                        id=tool_id
+                    )]
+                else:
+                    return []
         if self.streaming_state == StreamingState.PARSING_ARGUMENTS:
             next_function_text = None
             if self.bot_token in delta_text:
@@ -297,11 +300,12 @@ def _generate_delta_tool_call(self,
                         type="function",
                         id=tool_id,
                         function=DeltaFunctionCall(
-                            name=delta_function_name,
+                            name=self.current_tool_name,
                             arguments=delta_arguments).model_dump(
                                 exclude_none=True),
                     )
                 ]
+                self.current_tool_name = None
             if next_function_text:
                 ret += self._generate_delta_tool_call(next_function_text)
             return ret