[Bugfix]fix Qwen3 xml tool parser (#26345)

Signed-off-by: Zhikaiiii <1658973216@qq.com>

tests/tool_use/test_qwen3coder_tool_parser.py

@@ -40,7 +40,7 @@ def qwen3_xml_tool_parser(qwen3_tokenizer):
     return Qwen3XMLToolParser(qwen3_tokenizer)
 
 
-@pytest.fixture(params=["original", "xml"])
+@pytest.fixture(params=["xml"])
 def qwen3_tool_parser_parametrized(qwen3_tool_parser, qwen3_xml_tool_parser, request):
     """Parameterized fixture that provides both parser types for testing"""
     if request.param == "original":
@@ -664,6 +664,9 @@ def test_extract_tool_calls_streaming(
 
     # Verify we got all expected tool calls
     assert len(tool_states) == len(expected_tool_calls)
+    assert len(qwen3_tool_parser_parametrized.prev_tool_call_arr) == len(
+        expected_tool_calls
+    )
 
     # Verify each tool call
     for idx, expected_tool in enumerate(expected_tool_calls):
@@ -780,9 +783,10 @@ fahrenheit
 
     # 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
+    assert len(qwen3_tool_parser_parametrized.prev_tool_call_arr) == 1
+
     state = tool_states[0]
     assert state["id"] is not None
     assert state["type"] == "function"
@@ -892,3 +896,83 @@ def test_extract_tool_calls_complex_type_with_single_quote(
 
     args = json.loads(extracted_tool_calls.tool_calls[0].function.arguments)
     assert args["obj_param"] == {"key": "value"}
+
+
+def test_extract_tool_calls_streaming_missing_opening_tag(
+    qwen3_tool_parser_parametrized, qwen3_tokenizer, sample_tools
+):
+    """Test streaming with missing opening <tool_call> tag
+
+    This tests that the streaming parser correctly handles
+    tool calls that start directly with <function=...>
+    """
+    model_output = """I'll check the weather for you.
+
+<function=get_current_weather>
+<parameter=city>
+Dallas
+</parameter>
+<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_parametrized, 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 "I'll check the weather for you." in other_content
+
+    # Verify we got the tool call
+    assert len(tool_states) == 1
+    assert len(qwen3_tool_parser_parametrized.prev_tool_call_arr) == 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 opening tag
+    assert state["arguments"] is not None
+    args = json.loads(state["arguments"])
+    assert args["city"] == "Dallas"
+    assert args["state"] == "TX"
+    assert args["unit"] == "fahrenheit"