[Bugfix] Fix Deepseekv32 tool parser when stream interval > 1 (#36056)

tests/tool_parsers/test_deepseekv32_tool_parser.py

+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+"""Unit tests for DeepSeekV32ToolParser.
+
+These tests use a minimal mock tokenizer so no real model weights are required.
+"""
+
+import json
+from unittest.mock import MagicMock
+
+import pytest
+
+from vllm.tool_parsers.deepseekv32_tool_parser import DeepSeekV32ToolParser
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+# Token IDs are not used by the V32 parser logic, so we only need the
+# tokenizer object to be truthy (the parser checks `if not self.model_tokenizer`).
+MOCK_TOKENIZER = MagicMock()
+MOCK_TOKENIZER.get_vocab.return_value = {}
+
+
+def make_parser() -> DeepSeekV32ToolParser:
+    return DeepSeekV32ToolParser(MOCK_TOKENIZER)
+
+
+def make_tool_param(name: str, params: dict) -> MagicMock:
+    """Build a mock tool matching the ChatCompletionToolsParam shape."""
+    tool = MagicMock()
+    tool.function.name = name
+    tool.function.parameters = params
+    return tool
+
+
+def make_request(tools=None) -> MagicMock:
+    req = MagicMock()
+    req.tools = tools
+    return req
+
+
+# Shorthand for the DSML tokens used throughout
+FC_START = "<｜DSML｜function_calls>"
+FC_END = "</｜DSML｜function_calls>"
+INV_START = '<｜DSML｜invoke name="'
+INV_END = "</｜DSML｜invoke>"
+PARAM_START = '<｜DSML｜parameter name="'
+PARAM_END = "</｜DSML｜parameter>"
+
+
+def build_tool_call(func_name: str, params: dict[str, str]) -> str:
+    """Build a complete model-output tool call string."""
+    param_strs = "".join(
+        f'{PARAM_START}{k}" string="true">{v}{PARAM_END}' for k, v in params.items()
+    )
+    return f'{FC_START}\n{INV_START}{func_name}">\n{param_strs}\n{INV_END}\n{FC_END}'
+
+
+# ---------------------------------------------------------------------------
+# Tests: DeepSeekV32ToolParser._convert_param_value
+# ---------------------------------------------------------------------------
+
+
+class TestConvertParamValue:
+    @pytest.fixture
+    def parser(self):
+        return make_parser()
+
+    def test_null(self, parser):
+        assert parser._convert_param_value("null", "string") is None
+        assert parser._convert_param_value("NULL", "integer") is None
+
+    def test_string(self, parser):
+        assert parser._convert_param_value("hello", "string") == "hello"
+
+    def test_integer_valid(self, parser):
+        assert parser._convert_param_value("42", "integer") == 42
+
+    def test_integer_invalid_falls_back_to_str(self, parser):
+        assert parser._convert_param_value("abc", "int") == "abc"
+
+    def test_number_float(self, parser):
+        assert parser._convert_param_value("3.14", "number") == pytest.approx(3.14)
+
+    def test_number_whole_returns_int(self, parser):
+        assert parser._convert_param_value("5.0", "number") == 5
+        assert isinstance(parser._convert_param_value("5.0", "number"), int)
+
+    def test_boolean_true(self, parser):
+        assert parser._convert_param_value("true", "boolean") is True
+        assert parser._convert_param_value("1", "bool") is True
+
+    def test_boolean_false(self, parser):
+        assert parser._convert_param_value("false", "boolean") is False
+        assert parser._convert_param_value("False", "bool") is False
+
+    def test_object_valid_json(self, parser):
+        assert parser._convert_param_value('{"k": 1}', "object") == {"k": 1}
+
+    def test_object_invalid_json_falls_back(self, parser):
+        assert parser._convert_param_value("not-json", "object") == "not-json"
+
+    def test_array_valid_json(self, parser):
+        assert parser._convert_param_value("[1, 2]", "array") == [1, 2]
+
+    def test_unknown_type_tries_json_then_string(self, parser):
+        assert parser._convert_param_value("123", "unknown") == 123
+        assert parser._convert_param_value("hello", "unknown") == "hello"
+
+
+# ---------------------------------------------------------------------------
+# Tests: extract_tool_calls (non-streaming)
+# ---------------------------------------------------------------------------
+
+
+class TestExtractToolCalls:
+    @pytest.fixture
+    def parser(self):
+        return make_parser()
+
+    def test_no_tool_call(self, parser):
+        result = parser.extract_tool_calls("just some text", None)
+        assert not result.tools_called
+        assert result.tool_calls == []
+        assert result.content == "just some text"
+
+    def test_single_tool_no_params(self, parser):
+        model_output = f'{FC_START}\n{INV_START}get_time">\n{INV_END}\n{FC_END}'
+        result = parser.extract_tool_calls(model_output, None)
+        assert result.tools_called
+        assert len(result.tool_calls) == 1
+        assert result.tool_calls[0].function.name == "get_time"
+        assert json.loads(result.tool_calls[0].function.arguments) == {}
+
+    def test_single_tool_with_params(self, parser):
+        model_output = build_tool_call(
+            "get_weather", {"location": "SF", "date": "2024-01-16"}
+        )
+        result = parser.extract_tool_calls(model_output, None)
+        assert result.tools_called
+        assert len(result.tool_calls) == 1
+        tc = result.tool_calls[0]
+        assert tc.function.name == "get_weather"
+        assert json.loads(tc.function.arguments) == {
+            "location": "SF",
+            "date": "2024-01-16",
+        }
+
+    def test_content_before_tool_call(self, parser):
+        model_output = "Sure, let me check! " + build_tool_call(
+            "get_weather", {"location": "NYC"}
+        )
+        result = parser.extract_tool_calls(model_output, None)
+        assert result.tools_called
+        assert result.content == "Sure, let me check! "
+
+    def test_no_content_prefix_returns_none(self, parser):
+        model_output = build_tool_call("get_weather", {"location": "NYC"})
+        result = parser.extract_tool_calls(model_output, None)
+        assert result.tools_called
+        assert result.content is None
+
+    def test_multiple_tools(self, parser):
+        model_output = (
+            f"{FC_START}\n"
+            f'{INV_START}get_weather">\n'
+            f'{PARAM_START}location" string="true">SF{PARAM_END}\n'
+            f"{INV_END}\n"
+            f'{INV_START}get_weather">\n'
+            f'{PARAM_START}location" string="true">NYC{PARAM_END}\n'
+            f"{INV_END}\n"
+            f"{FC_END}"
+        )
+        result = parser.extract_tool_calls(model_output, None)
+        assert result.tools_called
+        assert len(result.tool_calls) == 2
+        assert json.loads(result.tool_calls[0].function.arguments) == {"location": "SF"}
+        assert json.loads(result.tool_calls[1].function.arguments) == {
+            "location": "NYC"
+        }
+
+
+# ---------------------------------------------------------------------------
+# Tests: extract_tool_calls_streaming
+# ---------------------------------------------------------------------------
+
+
+class TestExtractToolCallsStreaming:
+    """Simulate character-by-character streaming and verify reconstructed args."""
+
+    @pytest.fixture
+    def parser(self):
+        return make_parser()
+
+    def _stream(self, parser, full_text: str, request=None):
+        """Drive the parser line-by-line and collect non-None deltas.
+
+        Real tokenizers emit multi-character chunks, not individual characters.
+        Streaming character-by-character would never deliver the full sentinel
+        token (e.g. '｜DSML｜') in a single delta, so we split on newlines to
+        ensure each sentinel always lands in one chunk.
+        """
+        if request is None:
+            request = make_request()
+        # Split into lines, preserving the trailing newline in each chunk.
+        chunks: list[str] = []
+        remaining = full_text
+        while remaining:
+            nl = remaining.find("\n")
+            if nl == -1:
+                chunks.append(remaining)
+                break
+            chunks.append(remaining[: nl + 1])
+            remaining = remaining[nl + 1 :]
+
+        deltas = []
+        prev = ""
+        for chunk in chunks:
+            curr = prev + chunk
+            result = parser.extract_tool_calls_streaming(
+                previous_text=prev,
+                current_text=curr,
+                delta_text=chunk,
+                previous_token_ids=[],
+                current_token_ids=[],
+                delta_token_ids=[1],
+                request=request,
+            )
+            prev = curr
+            if result is not None:
+                deltas.append(result)
+        return deltas
+
+    def _reconstruct_args(self, deltas, tool_index=0) -> str:
+        """Concatenate all argument fragments for a given tool index."""
+        fragments = []
+        for d in deltas:
+            if d.tool_calls:
+                for tc in d.tool_calls:
+                    if tc.index == tool_index and tc.function and tc.function.arguments:
+                        fragments.append(tc.function.arguments)
+        return "".join(fragments)
+
+    def test_plain_content_no_tool(self, parser):
+        full_text = "Hello, world!"
+        deltas = self._stream(parser, full_text)
+        content = "".join(d.content for d in deltas if d.content is not None)
+        assert "Hello, world!" in content
+        assert all(not d.tool_calls for d in deltas)
+
+    def test_single_tool_streaming(self, parser):
+        full_text = build_tool_call("get_weather", {"location": "SF"})
+        deltas = self._stream(parser, full_text)
+        args_str = self._reconstruct_args(deltas)
+        assert json.loads(args_str) == {"location": "SF"}
+
+    def test_tool_name_emitted(self, parser):
+        full_text = build_tool_call("my_func", {"x": "1"})
+        deltas = self._stream(parser, full_text)
+        func_names = [
+            tc.function.name
+            for d in deltas
+            if d.tool_calls
+            for tc in d.tool_calls
+            if tc.function and tc.function.name
+        ]
+        assert any("my_func" in n for n in func_names)
+
+    def test_content_before_tool_call_streaming(self, parser):
+        full_text = "Thinking... " + build_tool_call("fn", {"a": "b"})
+        deltas = self._stream(parser, full_text)
+        content = "".join(d.content for d in deltas if d.content is not None)
+        assert "Thinking" in content
+
+    def test_type_conversion_in_streaming(self, parser):
+        tool = make_tool_param(
+            "add",
+            {
+                "type": "object",
+                "properties": {
+                    "x": {"type": "integer"},
+                    "y": {"type": "integer"},
+                },
+            },
+        )
+        request = make_request(tools=[tool])
+        full_text = build_tool_call("add", {"x": "3", "y": "4"})
+        deltas = self._stream(parser, full_text, request=request)
+        args_str = self._reconstruct_args(deltas)
+        assert json.loads(args_str) == {"x": 3, "y": 4}
+
+    def test_multiple_tools_streaming(self, parser):
+        full_text = (
+            f"{FC_START}\n"
+            f'{INV_START}func_a">\n'
+            f'{PARAM_START}p" string="true">v1{PARAM_END}\n'
+            f"{INV_END}\n"
+            f'{INV_START}func_b">\n'
+            f'{PARAM_START}q" string="true">v2{PARAM_END}\n'
+            f"{INV_END}\n"
+            f"{FC_END}"
+        )
+        deltas = self._stream(parser, full_text)
+
+        # Collect function names by index
+        names_by_index: dict[int, str] = {}
+        for d in deltas:
+            if d.tool_calls:
+                for tc in d.tool_calls:
+                    if tc.function and tc.function.name:
+                        names_by_index[tc.index] = tc.function.name
+
+        assert names_by_index.get(0) == "func_a"
+        assert names_by_index.get(1) == "func_b"
+
+        assert json.loads(self._reconstruct_args(deltas, tool_index=0)) == {"p": "v1"}
+        assert json.loads(self._reconstruct_args(deltas, tool_index=1)) == {"q": "v2"}
+
+    def test_state_reset_on_new_stream(self, parser):
+        """A second stream (previous_text == '') must reset state cleanly."""
+        full_text = build_tool_call("fn", {"k": "v"})
+        # First stream
+        self._stream(parser, full_text)
+        # Second stream - should produce identical results
+        deltas2 = self._stream(parser, full_text)
+        assert json.loads(self._reconstruct_args(deltas2)) == {"k": "v"}
+
+    def test_empty_arguments_streaming(self, parser):
+        """Invoke block with zero parameters should produce empty JSON."""
+        full_text = f'{FC_START}\n{INV_START}get_time">\n{INV_END}\n{FC_END}'
+        deltas = self._stream(parser, full_text)
+        args_str = self._reconstruct_args(deltas)
+        assert json.loads(args_str) == {}
+
+    def test_unique_tool_call_ids(self, parser):
+        """Each tool call in a parallel stream must get a distinct id."""
+        full_text = (
+            f"{FC_START}\n"
+            f'{INV_START}fn_a">\n'
+            f'{PARAM_START}x" string="true">1{PARAM_END}\n'
+            f"{INV_END}\n"
+            f'{INV_START}fn_b">\n'
+            f'{PARAM_START}y" string="true">2{PARAM_END}\n'
+            f"{INV_END}\n"
+            f"{FC_END}"
+        )
+        deltas = self._stream(parser, full_text)
+        ids = [
+            tc.id
+            for d in deltas
+            if d.tool_calls
+            for tc in d.tool_calls
+            if tc.id is not None
+        ]
+        assert len(ids) == 2
+        assert ids[0] != ids[1]
+
+    def test_eos_after_tool_calls(self, parser):
+        """EOS token (empty delta_text, non-empty delta_token_ids) returns
+        a non-None DeltaMessage so the serving framework can finalize."""
+        full_text = build_tool_call("fn", {"k": "v"})
+        # Drive through the full text first
+        deltas = self._stream(parser, full_text)
+        assert any(d.tool_calls for d in deltas)
+        # Now simulate EOS: empty delta_text, but token ids present
+        prev = full_text
+        result = parser.extract_tool_calls_streaming(
+            previous_text=prev,
+            current_text=prev,
+            delta_text="",
+            previous_token_ids=[],
+            current_token_ids=[],
+            delta_token_ids=[2],  # EOS token id
+            request=make_request(),
+        )
+        assert result is not None
+
+    def test_streaming_matches_non_streaming(self, parser):
+        """Streaming and non-streaming must produce the same result."""
+        full_text = build_tool_call(
+            "get_weather", {"location": "SF", "date": "2024-01-16"}
+        )
+        # Non-streaming
+        non_stream = parser.extract_tool_calls(full_text, None)
+        assert non_stream.tools_called
+        ns_name = non_stream.tool_calls[0].function.name
+        ns_args = json.loads(non_stream.tool_calls[0].function.arguments)
+        # Streaming
+        deltas = self._stream(parser, full_text)
+        s_names = [
+            tc.function.name
+            for d in deltas
+            if d.tool_calls
+            for tc in d.tool_calls
+            if tc.function and tc.function.name
+        ]
+        s_args = json.loads(self._reconstruct_args(deltas))
+        assert s_names[0] == ns_name
+        assert s_args == ns_args
+
+    def _stream_chunked(self, parser, full_text: str, chunk_size: int, request=None):
+        """Drive the parser with fixed-size chunks (simulates stream interval).
+
+        Unlike ``_stream`` which splits on newlines, this splits the text
+        into ``chunk_size``-character pieces so the start token can be
+        split across chunks — exactly what happens with stream interval > 1.
+        """
+        if request is None:
+            request = make_request()
+        chunks = [
+            full_text[i : i + chunk_size] for i in range(0, len(full_text), chunk_size)
+        ]
+        deltas = []
+        prev = ""
+        for chunk in chunks:
+            curr = prev + chunk
+            result = parser.extract_tool_calls_streaming(
+                previous_text=prev,
+                current_text=curr,
+                delta_text=chunk,
+                previous_token_ids=[],
+                current_token_ids=[],
+                delta_token_ids=[1],
+                request=request,
+            )
+            prev = curr
+            if result is not None:
+                deltas.append(result)
+        return deltas
+
+    def test_single_tool_chunked_stream_interval(self, parser):
+        """Start token split across chunks (stream interval > 1)."""
+        full_text = build_tool_call("get_weather", {"location": "SF"})
+        # Use a chunk size that splits the start token
+        deltas = self._stream_chunked(parser, full_text, chunk_size=5)
+        args_str = self._reconstruct_args(deltas)
+        assert json.loads(args_str) == {"location": "SF"}
+
+    def test_content_before_tool_chunked(self, parser):
+        """Content before tool call with chunked streaming."""
+        full_text = "Thinking... " + build_tool_call("fn", {"a": "b"})
+        deltas = self._stream_chunked(parser, full_text, chunk_size=7)
+        content = "".join(d.content for d in deltas if d.content is not None)
+        assert "Thinking" in content
+        args_str = self._reconstruct_args(deltas)
+        assert json.loads(args_str) == {"a": "b"}
+
+    def test_multiple_tools_chunked(self, parser):
+        """Multiple tools with chunked streaming."""
+        full_text = (
+            f"{FC_START}\n"
+            f'{INV_START}func_a">\n'
+            f'{PARAM_START}p" string="true">v1{PARAM_END}\n'
+            f"{INV_END}\n"
+            f'{INV_START}func_b">\n'
+            f'{PARAM_START}q" string="true">v2{PARAM_END}\n'
+            f"{INV_END}\n"
+            f"{FC_END}"
+        )
+        deltas = self._stream_chunked(parser, full_text, chunk_size=10)
+        assert json.loads(self._reconstruct_args(deltas, tool_index=0)) == {"p": "v1"}
+        assert json.loads(self._reconstruct_args(deltas, tool_index=1)) == {"q": "v2"}
+
+    def test_no_emission_while_incomplete(self, parser):
+        """No tool calls should be emitted until an invoke block completes."""
+        # Stream only a partial invoke (no closing tag)
+        partial_text = (
+            f"{FC_START}\n"
+            f'{INV_START}fn">\n'
+            f'{PARAM_START}k" string="true">val{PARAM_END}\n'
+        )
+        deltas = self._stream(parser, partial_text)
+        # Should have no tool call deltas yet
+        assert all(not d.tool_calls for d in deltas)

vllm/tool_parsers/deepseekv32_tool_parser.py

@@ -48,41 +48,12 @@ class DeepSeekV32ToolParser(ToolParser):
 
         self.prev_tool_call_arr: list[dict] = []
 
-        # Sentinel tokens
-        self.dsml_token: str = "｜DSML｜"
-        self.dsml_start_check: str = "<" + self.dsml_token
+        # Sentinel token
         self.tool_call_start_token: str = "<｜DSML｜function_calls>"
-        self.tool_call_end_token: str = "</｜DSML｜function_calls>"
-        self.invoke_start_prefix: str = "<｜DSML｜invoke name="
-        self.invoke_end_token: str = "</｜DSML｜invoke>"
-        self.parameter_prefix: str = "<｜DSML｜parameter name="
-        self.parameter_end_token: str = "</｜DSML｜parameter>"
-
-        # Streaming state variables
-        self.current_tool_name_sent: bool = False
-        # Override base class type - we use string IDs for tool calls
-        self.current_tool_id: str | None = None  # type: ignore
-        self.streamed_args_for_tool: list[str] = []
-        self.is_tool_call_started: bool = False
-        self.failed_count: int = 0
 
-        # Initialize streaming state variables
+        # Streaming state
+        self.is_tool_call_started: bool = False
         self.current_tool_index: int = 0
-        self.invoke_index: int = 0
-        self.header_sent: bool = False
-        self.current_function_name: str | None = None
-        self.current_param_name: str | None = None
-        self.current_param_value: str = ""
-        self.param_count: int = 0
-        self.in_param: bool = False
-        self.in_function: bool = False
-        self.json_started: bool = False
-        self.json_closed: bool = False
-        self.accumulated_params: dict = {}
-        self.streaming_request: ChatCompletionRequest | None = None
-
-        # Enhanced streaming state - reset for each new message
-        self._reset_streaming_state()
 
         # Regex patterns for complete parsing
         self.tool_call_complete_regex = re.compile(
@@ -106,10 +77,6 @@ class DeepSeekV32ToolParser(ToolParser):
             "vLLM Successfully import tool parser %s !", self.__class__.__name__
         )
 
-    def _generate_tool_call_id(self) -> str:
-        """Generate a unique tool call ID."""
-        return f"call_{uuid.uuid4().hex[:24]}"
-
     def adjust_request(self, request):
         request = super().adjust_request(request)
         if request.tools and request.tool_choice != "none":
@@ -122,33 +89,77 @@ class DeepSeekV32ToolParser(ToolParser):
             request.skip_special_tokens = False
         return request
 
-    def _reset_streaming_state(self):
-        """Reset all streaming state."""
-        self.current_tool_index = 0
-        self.invoke_index = 0
-        self.is_tool_call_started = False
-        self.header_sent = False
-        self.current_tool_id = None
-        self.current_function_name = None
-        self.current_param_name = None
-        self.current_param_value = ""
-        self.param_count = 0
-        self.in_param = False
-        self.in_function = False
-        self.json_started = False
-        self.json_closed = False
-        # Store accumulated parameters for type conversion
-        self.accumulated_params = {}
-        self.streaming_request = None
-        # Clear previous tool call history to avoid state pollution
-        self.prev_tool_call_arr.clear()
+    def _generate_tool_call_id(self) -> str:
+        """Generate a unique tool call ID."""
+        return f"call_{uuid.uuid4().hex[:24]}"
 
-    def _parse_invoke_params(self, invoke_str: str) -> dict | None:
+    def _parse_invoke_params(self, invoke_str: str) -> dict:
         param_dict = dict()
         for param_name, param_val in self.parameter_complete_regex.findall(invoke_str):
             param_dict[param_name] = param_val
         return param_dict
 
+    def _convert_param_value(self, value: str, param_type: str) -> Any:
+        """Convert parameter value to the correct type."""
+        if value.lower() == "null":
+            return None
+
+        param_type = param_type.lower()
+        if param_type in ["string", "str", "text"]:
+            return value
+        elif param_type in ["integer", "int"]:
+            try:
+                return int(value)
+            except (ValueError, TypeError):
+                return value
+        elif param_type in ["number", "float"]:
+            try:
+                val = float(value)
+                return val if val != int(val) else int(val)
+            except (ValueError, TypeError):
+                return value
+        elif param_type in ["boolean", "bool"]:
+            return value.lower() in ["true", "1"]
+        elif param_type in ["object", "array"]:
+            try:
+                return json.loads(value)
+            except json.JSONDecodeError:
+                return value
+        else:
+            # Try JSON parse first, fallback to string
+            try:
+                return json.loads(value)
+            except json.JSONDecodeError:
+                return value
+
+    def _convert_params_with_schema(
+        self,
+        function_name: str,
+        param_dict: dict[str, str],
+        request: ChatCompletionRequest | None,
+    ) -> dict[str, Any]:
+        """Convert raw string param values using the tool schema types."""
+        param_config: dict = {}
+        if request and request.tools:
+            for tool in request.tools:
+                if (
+                    hasattr(tool, "function")
+                    and tool.function.name == function_name
+                    and hasattr(tool.function, "parameters")
+                ):
+                    schema = tool.function.parameters
+                    if isinstance(schema, dict) and "properties" in schema:
+                        param_config = schema["properties"]
+                    break
+
+        converted: dict[str, Any] = {}
+        for name, value in param_dict.items():
+            param_type = "string"
+            if name in param_config and isinstance(param_config[name], dict):
+                param_type = param_config[name].get("type", "string")
+            converted[name] = self._convert_param_value(value, param_type)
+        return converted
+
     def extract_tool_calls(
         self,
         model_output: str,
@@ -200,56 +211,55 @@ class DeepSeekV32ToolParser(ToolParser):
                 tools_called=False, tool_calls=[], content=model_output
             )
 
-    def _extract_name(self, name_str: str) -> str:
-        """Extract name from quoted string."""
-        name_str = name_str.strip()
-        if (
-            name_str.startswith('"')
-            and name_str.endswith('"')
-            or name_str.startswith("'")
-            and name_str.endswith("'")
-        ):
-            return name_str[1:-1]
-        return name_str
-
-    def _extract_param_name(self, input_str: str) -> str:
-        """Extract param name"""
-        start = input_str.find('"') + 1
-        end = input_str.find('"', start)
-        return input_str[start:end] if start > 0 and end > start else input_str
+    def _reset_streaming_state(self):
+        """Reset all streaming state."""
+        self.current_tool_index = 0
+        self.is_tool_call_started = False
+        self.prev_tool_call_arr.clear()
+        self.streamed_args_for_tool.clear()
 
-    def _convert_param_value(self, value: str, param_type: str) -> Any:
-        """Convert parameter value to the correct type."""
-        if value.lower() == "null":
-            return None
+    def _extract_delta_tool_calls(
+        self,
+        current_text: str,
+        request: ChatCompletionRequest | None,
+    ) -> list[DeltaToolCall]:
+        """Extract DeltaToolCalls from newly completed <invoke> blocks.
+
+        Tracks progress via ``current_tool_index`` so each block is
+        extracted exactly once across successive streaming calls.
+        """
+        complete_invokes = self.invoke_complete_regex.findall(current_text)
+        delta_tool_calls: list[DeltaToolCall] = []
+
+        while len(complete_invokes) > self.current_tool_index:
+            invoke_name, invoke_body = complete_invokes[self.current_tool_index]
+            param_dict = self._parse_invoke_params(invoke_body)
+
+            converted = self._convert_params_with_schema(
+                invoke_name, param_dict, request
+            )
+            args_json = json.dumps(converted, ensure_ascii=False)
+            idx = self.current_tool_index
+            self.current_tool_index += 1
 
-        param_type = param_type.lower()
-        if param_type in ["string", "str", "text"]:
-            return value
-        elif param_type in ["integer", "int"]:
-            try:
-                return int(value)
-            except (ValueError, TypeError):
-                return value
-        elif param_type in ["number", "float"]:
-            try:
-                val = float(value)
-                return val if val != int(val) else int(val)
-            except (ValueError, TypeError):
-                return value
-        elif param_type in ["boolean", "bool"]:
-            return value.lower() in ["true", "1"]
-        elif param_type in ["object", "array"]:
-            try:
-                return json.loads(value)
-            except json.JSONDecodeError:
-                return value
-        else:
-            # Try JSON parse first, fallback to string
-            try:
-                return json.loads(value)
-            except json.JSONDecodeError:
-                return value
+            self.prev_tool_call_arr.append(
+                {"name": invoke_name, "arguments": converted}
+            )
+            self.streamed_args_for_tool.append(args_json)
+
+            delta_tool_calls.append(
+                DeltaToolCall(
+                    index=idx,
+                    id=self._generate_tool_call_id(),
+                    function=DeltaFunctionCall(
+                        name=invoke_name,
+                        arguments=args_json,
+                    ),
+                    type="function",
+                )
+            )
+
+        return delta_tool_calls
 
     def extract_tool_calls_streaming(
         self,
@@ -261,345 +271,44 @@ class DeepSeekV32ToolParser(ToolParser):
         delta_token_ids: Sequence[int],
         request: ChatCompletionRequest,
     ) -> DeltaMessage | None:
-        """Extract tool calls from streaming model output."""
+        """Extract tool calls from streaming model output.
+
+        Uses a buffer-until-complete-invoke strategy: tokens are buffered
+        until a complete invoke block is available, then parsed and emitted
+        in one shot.
+        """
 
-        # Store request for type conversion
+        # First chunk of a new stream — reset state from prior request.
         if not previous_text:
             self._reset_streaming_state()
-            self.streaming_request = request
-
-        # If no delta text, return None unless it's an EOS token after tools
-        if not delta_text:
-            # Check if this is an EOS token after all tool calls are complete
-            if delta_token_ids:
-                # Count complete tool calls
-                complete_calls = len(
-                    self.tool_call_complete_regex.findall(current_text)
-                )
-
-                # If we have completed tool calls and populated prev_tool_call_arr
-                if complete_calls > 0 and len(self.prev_tool_call_arr) > 0:
-                    # Check if all tool calls are closed
-                    open_calls = current_text.count(
-                        self.tool_call_start_token
-                    ) - current_text.count(self.tool_call_end_token)
-                    if open_calls == 0:
-                        # Return empty delta for finish_reason processing
-                        return DeltaMessage(content="")
-                elif not self.is_tool_call_started and current_text:
-                    # This is a regular content response that's now complete
-                    return DeltaMessage(content="")
-            return None
-
-        # Check if we need to advance to next tool
-        if self.json_closed and not self.in_function:
-            # Check if this tool call has ended
-            invoke_ends = current_text.count(self.invoke_end_token)
-            if invoke_ends > self.current_tool_index:
-                # This tool has ended, advance to next
-                self.current_tool_index += 1
-                self.header_sent = False
-                self.param_count = 0
-                self.json_started = False
-                self.json_closed = False
-                self.in_function = False  # Now we can safely set this to False
-                self.accumulated_params = {}
-                # Continue processing next tool
-                return None
-
-        # Handle normal content before tool calls
-        if not self.is_tool_call_started:
-            # Check if tool call is starting
-            if self.dsml_token in current_text:
-                self.is_tool_call_started = True
-                # Return any content before the tool call
-                if self.dsml_start_check in delta_text:
-                    content_before = delta_text[
-                        : delta_text.index(self.dsml_start_check)
-                    ]
-                    if content_before:
-                        return DeltaMessage(content=content_before)
-                return None
-            else:
-                # Check if we're between tool calls - skip whitespace
-                if (
-                    current_text.rstrip().endswith(self.tool_call_end_token)
-                    and delta_text.strip() == ""
-                ):
-                    # We just ended a tool call, skip whitespace
-                    return None
-                # Normal content, no tool call
-                if delta_text.endswith("<"):
-                    return DeltaMessage(content=delta_text[:-1])
-                if previous_text and previous_text.endswith("<"):
-                    return DeltaMessage(content="<" + delta_text)
-                return DeltaMessage(content=delta_text)
-
-        # Check if we're between tool calls (waiting for next one)
-        invoke_starts_count = current_text.count(self.invoke_start_prefix)
-        if self.current_tool_index >= invoke_starts_count:
-            # We're past all tool calls, shouldn't be here
-            return None
-
-        # Find the current tool call portion
-        invoke_start_positions: list[int] = []
-        idx = 0
-        while True:
-            idx = current_text.find(self.invoke_start_prefix, idx)
-            if idx == -1:
-                break
-            invoke_start_positions.append(idx)
-            idx += len(self.invoke_start_prefix)
-
-        if self.current_tool_index >= len(invoke_start_positions):
-            # No more tool calls to process yet
-            return None
 
-        invoke_start_idx = invoke_start_positions[self.current_tool_index]
-        # Find where this tool call ends (or current position if not ended yet)
-        invoke_end_idx = current_text.find(self.invoke_end_token, invoke_start_idx)
-        if invoke_end_idx == -1:
-            tool_text = current_text[invoke_start_idx:]
+        # Detect whether we've entered the tool-call region.
+        # Use current_text (not delta_text) since the start token may
+        # be split across chunks.
+        content_before = None
+        if self.is_tool_call_started:
+            pass
+        elif self.tool_call_start_token in current_text:
+            # Tool-call region found, capture any plain text before it.
+            self.is_tool_call_started = True
+            start_idx = current_text.index(self.tool_call_start_token)
+            content_before = current_text[len(previous_text) : start_idx] or None
         else:
-            tool_text = current_text[
-                invoke_start_idx : invoke_end_idx + len(self.invoke_end_token)
-            ]
-
-        # Looking for function header
-        if not self.header_sent:
-            if self.invoke_start_prefix in tool_text:
-                func_start = tool_text.find(self.invoke_start_prefix) + len(
-                    self.invoke_start_prefix
-                )
-                # Find the end quote for the function name
-                func_end = tool_text.find(">", func_start)
-
-                if func_end != -1:
-                    # Found complete function name
-                    function_name_raw = tool_text[func_start:func_end]
-                    self.current_function_name = self._extract_name(function_name_raw)
-                    self.current_tool_id = self._generate_tool_call_id()
-                    self.header_sent = True
-                    self.in_function = True
-
-                    # Add to prev_tool_call_arr immediately when we detect a tool call
-                    # Each tool call should be recorded regardless of function name
-                    # Ensure we don't add the same tool call index multiple times
-                    if len(self.prev_tool_call_arr) <= self.current_tool_index:
-                        self.prev_tool_call_arr.append(
-                            {
-                                "name": self.current_function_name,
-                                "arguments": "{}",  # Placeholder, will be updated later
-                            }
-                        )
+            # Still in plain-text region, forward as content.
+            return DeltaMessage(content=delta_text) if delta_text else None
 
-                    # Send header with function info
-                    return DeltaMessage(
-                        tool_calls=[
-                            DeltaToolCall(
-                                index=self.current_tool_index,
-                                id=self.current_tool_id,
-                                function=DeltaFunctionCall(
-                                    name=self.current_function_name, arguments=""
-                                ),
-                                type="function",
-                            )
-                        ]
-                    )
-            return None
+        # Inside tool-call region: emit any newly completed invokes.
+        delta_tool_calls = self._extract_delta_tool_calls(current_text, request)
 
-        # We've sent header, now handle function body
-        if self.in_function:
-            # Send opening brace if not sent yet
-            if self.in_function and not self.json_started:
-                self.json_started = True
-                return DeltaMessage(
-                    tool_calls=[
-                        DeltaToolCall(
-                            index=self.current_tool_index,
-                            function=DeltaFunctionCall(arguments="{"),
-                        )
-                    ]
-                )
-
-            # Make sure json_started is set if we're processing parameters
-            if not self.json_started:
-                self.json_started = True
-
-            # Check for function end in accumulated text
-            if not self.json_closed and self.invoke_end_token in tool_text:
-                # Count total parameters in the tool text
-                total_param_count = tool_text.count(self.parameter_prefix)
-
-                # Only close JSON if all parameters have been processed
-                if self.param_count >= total_param_count:
-                    # Close JSON
-                    self.json_closed = True
-
-                    # Extract complete tool call
-                    # Find the invoke content
-                    invoke_start = tool_text.find(self.invoke_start_prefix) + len(
-                        self.invoke_start_prefix
-                    )
-                    invoke_content_end = tool_text.find(
-                        self.invoke_end_token, invoke_start
-                    )
-                    if invoke_content_end != -1:
-                        invoke_content = tool_text[invoke_start:invoke_content_end]
-                        # Parse to get the complete arguments
-                        try:
-                            invoke_params = self._parse_invoke_params(invoke_content)
-                            if invoke_params and self.current_tool_index < len(
-                                self.prev_tool_call_arr
-                            ):
-                                # Update existing entry in prev_tool_call_arr
-                                self.prev_tool_call_arr[self.current_tool_index][
-                                    "arguments"
-                                ] = json.dumps(invoke_params, ensure_ascii=False)
-                        except Exception:
-                            pass  # Ignore parsing errors during streaming
-
-                    result = DeltaMessage(
-                        tool_calls=[
-                            DeltaToolCall(
-                                index=self.current_tool_index,
-                                function=DeltaFunctionCall(arguments="}"),
-                            )
-                        ]
-                    )
-
-                    # Reset state for next tool
-                    self.json_closed = True
-                    self.in_function = False
-                    self.accumulated_params = {}
-
-                    logger.debug("[M2_STREAMING] Tool call completed")
-
-                    return result
-                else:
-                    # Don't close JSON yet, continue processing parameters
-                    return None
-
-            # Look for parameters
-            # Find all parameter starts
-            param_starts = []
-            idx = 0
-            while True:
-                idx = tool_text.find(self.parameter_prefix, idx)
-                if idx == -1:
-                    break
-                param_starts.append(idx)
-                idx += len(self.parameter_prefix)
-
-            # Check if we should start a new parameter
-            if (
-                not self.in_param
-                and self.param_count < len(param_starts)
-                and len(param_starts) > self.param_count
-            ):
-                # Process the next parameter
-                param_idx = param_starts[self.param_count]
-                param_start = param_idx + len(self.parameter_prefix)
-                remaining = tool_text[param_start:]
-
-                if ">" in remaining:
-                    # We have the complete parameter name
-                    name_end = remaining.find(">")
-                    param_name_raw = remaining[:name_end]
-                    self.current_param_name = self._extract_param_name(param_name_raw)
-
-                    # Find the parameter value
-                    value_start = param_start + name_end + 1
-                    value_text = tool_text[value_start:]
-                    if value_text.startswith("\n"):
-                        value_text = value_text[1:]
-
-                    # Find where this parameter ends
-                    param_end_idx = value_text.find(self.parameter_end_token)
-                    if param_end_idx == -1:
-                        # No closing tag, look for next parameter or function end
-                        next_param_idx = value_text.find(self.parameter_prefix)
-                        func_end_idx = value_text.find(self.invoke_end_token)
-
-                        if next_param_idx != -1 and (
-                            func_end_idx == -1 or next_param_idx < func_end_idx
-                        ):
-                            param_end_idx = next_param_idx
-                        elif func_end_idx != -1:
-                            param_end_idx = func_end_idx
-                        else:
-                            # Neither found, check if tool call is complete
-                            if self.invoke_end_token in tool_text:
-                                # Tool call and parameter is complete
-                                param_end_idx = len(value_text)
-                            else:
-                                # Still streaming, wait for more content
-                                return None
-
-                    if param_end_idx != -1:
-                        # Complete parameter found
-                        param_value = value_text[:param_end_idx]
-                        if param_value.endswith("\n"):
-                            param_value = param_value[:-1]
-
-                        # Store raw value for later processing
-                        self.accumulated_params[self.current_param_name] = param_value
-
-                        # Get parameter configuration for type conversion
-                        param_config = {}
-                        if self.streaming_request and self.streaming_request.tools:
-                            for tool in self.streaming_request.tools:
-                                if (
-                                    hasattr(tool, "function")
-                                    and tool.function.name == self.current_function_name
-                                    and hasattr(tool.function, "parameters")
-                                ):
-                                    params = tool.function.parameters
-                                    if (
-                                        isinstance(params, dict)
-                                        and "properties" in params
-                                    ):
-                                        param_config = params["properties"]
-                                    break
-
-                        # Get parameter type
-                        param_type = "string"
-                        if (
-                            self.current_param_name in param_config
-                            and isinstance(param_config[self.current_param_name], dict)
-                            and "type" in param_config[self.current_param_name]
-                        ):
-                            param_type = param_config[self.current_param_name]["type"]
-
-                        # Convert param value to appropriate type
-                        converted_value = self._convert_param_value(
-                            param_value, param_type
-                        )
-
-                        # Build JSON fragment based on the converted type
-                        # Use json.dumps to properly serialize the value
-                        serialized_value = json.dumps(
-                            converted_value, ensure_ascii=False
-                        )
+        if delta_tool_calls or content_before:
+            return DeltaMessage(
+                content=content_before,
+                tool_calls=delta_tool_calls,
+            )
 
-                        if self.param_count == 0:
-                            json_fragment = (
-                                f'"{self.current_param_name}": {serialized_value}'
-                            )
-                        else:
-                            json_fragment = (
-                                f', "{self.current_param_name}": {serialized_value}'
-                            )
-
-                        self.param_count += 1
-
-                        return DeltaMessage(
-                            tool_calls=[
-                                DeltaToolCall(
-                                    index=self.current_tool_index,
-                                    function=DeltaFunctionCall(arguments=json_fragment),
-                                )
-                            ]
-                        )
+        # Empty delta with token ids means EOS or closing tag; return
+        # non-None so the serving framework can finalize finish_reason.
+        if not delta_text and delta_token_ids and self.prev_tool_call_arr:
+            return DeltaMessage(content="")
 
         return None