[Bugfix]: Qwen3 Coder Tool Parser (#23099)

Signed-off-by: Yiheng Xu <charlesyihengxu@gmail.com>
Co-authored-by: Aaron Pham <contact@aarnphm.xyz>

tests/tool_use/test_qwen3coder_tool_parser.py

@@ -16,7 +16,7 @@ from vllm.entrypoints.openai.tool_parsers.qwen3coder_tool_parser import (
 from vllm.transformers_utils.detokenizer import detokenize_incrementally
 from vllm.transformers_utils.tokenizer import AnyTokenizer, get_tokenizer
 
-MODEL = "Qwen/Qwen3-Coder-480B-A35B-Instruct-FP8"
+MODEL = "Qwen/Qwen3-Coder-30B-A3B-Instruct-FP8"
 
 
 @pytest.fixture(scope="module")
@@ -397,7 +397,9 @@ hello world
         "no_tools",
         "single_tool",
         "single_tool_with_content",
+        "single_tool_multiline_param",
         "parallel_tools",
+        "tool_with_typed_params",  # Added this test case
     ],
     argnames=["model_output", "expected_tool_calls", "expected_content"],
     argvalues=[
@@ -422,7 +424,7 @@ fahrenheit
                                           "state": "TX",
                                           "unit": "fahrenheit"
                                       })))
-        ], ""),
+        ], None),
         ('''Sure! Let me check the weather for you.<tool_call>
 <function=get_current_weather>
 <parameter=city>
@@ -445,6 +447,30 @@ fahrenheit
                                       })))
         ], "Sure! Let me check the weather for you."),
         ('''<tool_call>
+<function=calculate_area>
+<parameter=shape>
+rectangle
+</parameter>
+<parameter=dimensions>
+{"width": 10, 
+ "height": 20}
+</parameter>
+<parameter=precision>
+2
+</parameter>
+</function>
+</tool_call>''', [
+            ToolCall(function=FunctionCall(name="calculate_area",
+                                           arguments=json.dumps({
+                                               "shape": "rectangle",
+                                               "dimensions": {
+                                                   "width": 10,
+                                                   "height": 20
+                                               },
+                                               "precision": 2
+                                           })))
+        ], None),
+        ('''<tool_call>
 <function=get_current_weather>
 <parameter=city>
 Dallas
@@ -484,13 +510,36 @@ celsius
                                           "state": "FL",
                                           "unit": "celsius"
                                       })))
-        ], ""),
+        ], None),
+        # Added tool_with_typed_params test case
+        ('''Let me calculate that area for you.<tool_call>
+<function=calculate_area>
+<parameter=shape>
+circle
+</parameter>
+<parameter=dimensions>
+{"radius": 15.5}
+</parameter>
+<parameter=precision>
+3
+</parameter>
+</function>
+</tool_call>''', [
+            ToolCall(function=FunctionCall(name="calculate_area",
+                                           arguments=json.dumps({
+                                               "shape": "circle",
+                                               "dimensions": {
+                                                   "radius": 15.5
+                                               },
+                                               "precision": 3
+                                           })))
+        ], "Let me calculate that area for you."),
     ],
 )
 def test_extract_tool_calls_streaming(qwen3_tool_parser, qwen3_tokenizer,
                                       sample_tools, model_output,
                                       expected_tool_calls, expected_content):
-    """Test incremental streaming behavior"""
+    """Test incremental streaming behavior including typed parameters"""
     request = ChatCompletionRequest(model=MODEL,
                                     messages=[],
                                     tools=sample_tools)
@@ -539,7 +588,7 @@ def test_extract_tool_calls_streaming(qwen3_tool_parser, qwen3_tokenizer,
                             "arguments"] += tool_call.function.arguments
 
     # Verify final content
-    assert other_content == expected_content
+    assert other_content == (expected_content or "")  # Handle None case
 
     # Verify we got all expected tool calls
     assert len(tool_states) == len(expected_tool_calls)
@@ -559,6 +608,125 @@ def test_extract_tool_calls_streaming(qwen3_tool_parser, qwen3_tokenizer,
         assert actual_args == expected_args
 
 
+def test_extract_tool_calls_missing_closing_parameter_tag(
+        qwen3_tool_parser, sample_tools):
+    """Test handling of missing closing </parameter> tag"""
+    # Using get_current_weather from sample_tools but with malformed XML
+    model_output = '''Let me check the weather for you:
+<tool_call>
+<function=get_current_weather>
+<parameter=city>
+Dallas
+<parameter=state>
+TX
+</parameter>
+<parameter=unit>
+fahrenheit
+</parameter>
+</function>
+</tool_call>'''
+
+    request = ChatCompletionRequest(model=MODEL,
+                                    messages=[],
+                                    tools=sample_tools)
+    extracted_tool_calls = qwen3_tool_parser.extract_tool_calls(
+        model_output, request=request)
+
+    # The parser should handle the malformed XML gracefully
+    assert extracted_tool_calls.tools_called
+    assert len(extracted_tool_calls.tool_calls) == 1
+
+    # Verify the function name is correct
+    assert extracted_tool_calls.tool_calls[
+        0].function.name == "get_current_weather"
+
+    # Verify the arguments are parsed despite the missing closing tag
+    args = json.loads(extracted_tool_calls.tool_calls[0].function.arguments)
+    assert "city" in args
+    assert args["city"] == "Dallas"
+    assert args["state"] == "TX"
+    assert args["unit"] == "fahrenheit"
+
+    # Check that content before the tool call is preserved
+    assert "Let me check the weather for you:" in extracted_tool_calls.content
+
+
+def test_extract_tool_calls_streaming_missing_closing_tag(
+        qwen3_tool_parser, qwen3_tokenizer, sample_tools):
+    """Test streaming with missing closing </parameter> tag"""
+    # Using get_current_weather from sample_tools but with malformed XML
+    model_output = '''Let me check the weather for you:
+<tool_call>
+<function=get_current_weather>
+<parameter=city>
+Dallas
+<parameter=state>
+TX
+</parameter>
+<parameter=unit>
+fahrenheit
+</parameter>
+</function>
+</tool_call>'''
+
+    request = ChatCompletionRequest(model=MODEL,
+                                    messages=[],
+                                    tools=sample_tools)
+
+    other_content = ''
+    tool_states = {}
+
+    for delta_message in stream_delta_message_generator(
+            qwen3_tool_parser, qwen3_tokenizer, model_output, request):
+
+        if delta_message.content:
+            other_content += delta_message.content
+
+        if delta_message.tool_calls:
+            for tool_call in delta_message.tool_calls:
+                idx = tool_call.index
+
+                if idx not in tool_states:
+                    tool_states[idx] = {
+                        "id": None,
+                        "name": None,
+                        "arguments": "",
+                        "type": None
+                    }
+
+                if tool_call.id:
+                    tool_states[idx]["id"] = tool_call.id
+
+                if tool_call.type:
+                    assert tool_call.type == "function"
+                    tool_states[idx]["type"] = tool_call.type
+
+                if tool_call.function:
+                    if tool_call.function.name:
+                        tool_states[idx]["name"] = tool_call.function.name
+
+                    if tool_call.function.arguments is not None:
+                        tool_states[idx][
+                            "arguments"] += tool_call.function.arguments
+
+    # Verify content was streamed
+    assert "Let me check the weather for you:" in other_content
+
+    # Verify we got the tool call
+    assert len(tool_states) == 1
+    state = tool_states[0]
+    assert state["id"] is not None
+    assert state["type"] == "function"
+    assert state["name"] == "get_current_weather"
+
+    # Verify arguments were parsed correctly despite missing closing tag
+    assert state["arguments"] is not None
+    args = json.loads(state["arguments"])
+    assert args["city"] == "Dallas"
+    assert args["state"] == "TX"
+    assert args["unit"] == "fahrenheit"
+
+
 def test_extract_tool_calls_streaming_incremental(qwen3_tool_parser,
                                                   qwen3_tokenizer,
                                                   sample_tools):