From 30f5b8760851bb3aafdb7babe70bc726e58b9994 Mon Sep 17 00:00:00 2001
From: Lidang Jiang <119769478+Lidang-Jiang@users.noreply.github.com>
Date: Mon, 6 Apr 2026 10:29:55 +0800
Subject: [PATCH] [CI] Add unit tests for function_call detectors (hermes,
 llama32, mistral) (#21399)

---
 .../function_call/test_hermes_detector.py     | 179 ++++++++++++++
 .../function_call/test_llama32_detector.py    | 192 +++++++++++++++
 .../function_call/test_mistral_detector.py    | 224 ++++++++++++++++++
 3 files changed, 595 insertions(+)
 create mode 100644 test/registered/unit/function_call/test_hermes_detector.py
 create mode 100644 test/registered/unit/function_call/test_llama32_detector.py
 create mode 100644 test/registered/unit/function_call/test_mistral_detector.py

diff --git a/test/registered/unit/function_call/test_hermes_detector.py b/test/registered/unit/function_call/test_hermes_detector.py
new file mode 100644
index 000000000..d1a67c3ae
--- /dev/null
+++ b/test/registered/unit/function_call/test_hermes_detector.py
@@ -0,0 +1,179 @@
+"""Unit tests for HermesDetector — no server, no model loading."""
+
+import json
+
+from sglang.srt.entrypoints.openai.protocol import Function, Tool
+from sglang.srt.function_call.hermes_detector import HermesDetector
+from sglang.test.ci.ci_register import register_cpu_ci
+from sglang.test.test_utils import CustomTestCase
+
+register_cpu_ci(1.0, "stage-a-test-cpu")
+
+
+class TestHermesDetector(CustomTestCase):
+    def setUp(self):
+        self.tools = [
+            Tool(
+                type="function",
+                function=Function(
+                    name="get_weather",
+                    description="Get weather information",
+                    parameters={
+                        "type": "object",
+                        "properties": {
+                            "city": {"type": "string", "description": "City name"},
+                            "unit": {
+                                "type": "string",
+                                "enum": ["celsius", "fahrenheit"],
+                            },
+                        },
+                        "required": ["city"],
+                    },
+                ),
+            ),
+            Tool(
+                type="function",
+                function=Function(
+                    name="search",
+                    description="Search the web",
+                    parameters={
+                        "type": "object",
+                        "properties": {
+                            "query": {
+                                "type": "string",
+                                "description": "Search query",
+                            },
+                        },
+                        "required": ["query"],
+                    },
+                ),
+            ),
+        ]
+        self.detector = HermesDetector()
+
+    # ==================== has_tool_call Tests ====================
+
+    def test_has_tool_call_true(self):
+        text = '<tool_call>{"name": "get_weather", "arguments": {"city": "Beijing"}}</tool_call>'
+        self.assertTrue(self.detector.has_tool_call(text))
+
+    def test_has_tool_call_false(self):
+        text = "The weather in Beijing is sunny today."
+        self.assertFalse(self.detector.has_tool_call(text))
+
+    # ==================== detect_and_parse Tests ====================
+
+    def test_single_tool_call(self):
+        text = '<tool_call>{"name": "get_weather", "arguments": {"city": "Beijing"}}</tool_call>'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.calls[0].name, "get_weather")
+        args = json.loads(result.calls[0].parameters)
+        self.assertEqual(args["city"], "Beijing")
+        self.assertEqual(result.normal_text, "")
+
+    def test_multiple_tool_calls(self):
+        text = (
+            '<tool_call>{"name": "get_weather", "arguments": {"city": "Beijing"}}</tool_call>'
+            '<tool_call>{"name": "search", "arguments": {"query": "restaurants"}}</tool_call>'
+        )
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 2)
+        self.assertEqual(result.calls[0].name, "get_weather")
+        self.assertEqual(result.calls[1].name, "search")
+
+    def test_tool_call_with_leading_text(self):
+        text = 'I will check the weather for you. <tool_call>{"name": "get_weather", "arguments": {"city": "Tokyo"}}</tool_call>'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.calls[0].name, "get_weather")
+        self.assertEqual(result.normal_text, "I will check the weather for you.")
+
+    def test_no_tool_call(self):
+        text = "The weather is nice today."
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 0)
+        self.assertEqual(result.normal_text, "The weather is nice today.")
+
+    def test_tool_call_with_multiple_arguments(self):
+        text = '<tool_call>{"name": "get_weather", "arguments": {"city": "London", "unit": "celsius"}}</tool_call>'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        args = json.loads(result.calls[0].parameters)
+        self.assertEqual(args["city"], "London")
+        self.assertEqual(args["unit"], "celsius")
+
+    def test_malformed_json_returns_original_text(self):
+        text = "<tool_call>not valid json</tool_call>"
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 0)
+        self.assertEqual(result.normal_text, text)
+
+    # ==================== structure_info Tests ====================
+
+    def test_structure_info(self):
+        info_func = self.detector.structure_info()
+        info = info_func("get_weather")
+        self.assertIn("get_weather", info.begin)
+        self.assertEqual(info.trigger, "<tool_call>")
+        self.assertEqual(info.end, "}</tool_call>")
+
+    # ==================== Streaming Tests ====================
+
+    def test_streaming_single_tool_call(self):
+        detector = HermesDetector()
+        chunks = [
+            "<tool_",
+            'call>{"name": "get_weather",',
+            ' "arguments": {"city": "Beijing"',
+            "}}</tool_call>",
+        ]
+        all_calls = []
+        for chunk in chunks:
+            result = detector.parse_streaming_increment(chunk, self.tools)
+            all_calls.extend(result.calls)
+
+        # Verify tool name
+        func_calls = [c for c in all_calls if c.name]
+        self.assertEqual(len(func_calls), 1)
+        self.assertEqual(func_calls[0].name, "get_weather")
+
+        # Verify parameters
+        full_params = "".join(c.parameters for c in all_calls if c.parameters)
+        params = json.loads(full_params)
+        self.assertEqual(params["city"], "Beijing")
+
+    def test_streaming_normal_text_before_tool(self):
+        detector = HermesDetector()
+        result = detector.parse_streaming_increment("Hello! Let me help. ", self.tools)
+        self.assertEqual(result.normal_text, "Hello! Let me help. ")
+        self.assertEqual(len(result.calls), 0)
+
+    def test_streaming_text_then_tool_call(self):
+        detector = HermesDetector()
+        chunks = [
+            "Sure, let me check. ",
+            '<tool_call>{"name": "get_weather",',
+            ' "arguments": {"city": "Tokyo"',
+            "}}</tool_call>",
+        ]
+        all_calls = []
+        all_normal_text = ""
+        for chunk in chunks:
+            result = detector.parse_streaming_increment(chunk, self.tools)
+            all_calls.extend(result.calls)
+            all_normal_text += result.normal_text
+
+        self.assertEqual(all_normal_text, "Sure, let me check. ")
+        func_calls = [c for c in all_calls if c.name]
+        self.assertEqual(len(func_calls), 1)
+        self.assertEqual(func_calls[0].name, "get_weather")
+        full_params = "".join(c.parameters for c in all_calls if c.parameters)
+        params = json.loads(full_params)
+        self.assertEqual(params["city"], "Tokyo")
+
+
+if __name__ == "__main__":
+    import unittest
+
+    unittest.main()
diff --git a/test/registered/unit/function_call/test_llama32_detector.py b/test/registered/unit/function_call/test_llama32_detector.py
new file mode 100644
index 000000000..db828ef04
--- /dev/null
+++ b/test/registered/unit/function_call/test_llama32_detector.py
@@ -0,0 +1,192 @@
+"""Unit tests for Llama32Detector — no server, no model loading."""
+
+import json
+
+from sglang.srt.entrypoints.openai.protocol import Function, Tool
+from sglang.srt.function_call.llama32_detector import Llama32Detector
+from sglang.test.ci.ci_register import register_cpu_ci
+from sglang.test.test_utils import CustomTestCase
+
+register_cpu_ci(1.0, "stage-a-test-cpu")
+
+
+class TestLlama32Detector(CustomTestCase):
+    def setUp(self):
+        self.tools = [
+            Tool(
+                type="function",
+                function=Function(
+                    name="get_weather",
+                    description="Get weather information",
+                    parameters={
+                        "type": "object",
+                        "properties": {
+                            "city": {"type": "string", "description": "City name"},
+                            "unit": {
+                                "type": "string",
+                                "enum": ["celsius", "fahrenheit"],
+                            },
+                        },
+                        "required": ["city"],
+                    },
+                ),
+            ),
+            Tool(
+                type="function",
+                function=Function(
+                    name="search",
+                    description="Search the web",
+                    parameters={
+                        "type": "object",
+                        "properties": {
+                            "query": {
+                                "type": "string",
+                                "description": "Search query",
+                            },
+                        },
+                        "required": ["query"],
+                    },
+                ),
+            ),
+        ]
+        self.detector = Llama32Detector()
+
+    # ==================== has_tool_call Tests ====================
+
+    def test_has_tool_call_with_python_tag(self):
+        text = '<|python_tag|>{"name": "get_weather", "arguments": {"city": "Beijing"}}'
+        self.assertTrue(self.detector.has_tool_call(text))
+
+    def test_has_tool_call_with_json_start(self):
+        text = '{"name": "get_weather", "arguments": {"city": "Beijing"}}'
+        self.assertTrue(self.detector.has_tool_call(text))
+
+    def test_has_tool_call_false(self):
+        text = "The weather in Beijing is sunny today."
+        self.assertFalse(self.detector.has_tool_call(text))
+
+    # ==================== detect_and_parse Tests ====================
+
+    def test_single_tool_call_with_python_tag(self):
+        text = '<|python_tag|>{"name": "get_weather", "arguments": {"city": "Beijing"}}'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.calls[0].name, "get_weather")
+        args = json.loads(result.calls[0].parameters)
+        self.assertEqual(args["city"], "Beijing")
+
+    def test_single_tool_call_without_python_tag(self):
+        text = '{"name": "get_weather", "arguments": {"city": "Beijing"}}'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.calls[0].name, "get_weather")
+
+    def test_normal_text_before_python_tag(self):
+        text = 'Let me check. <|python_tag|>{"name": "get_weather", "arguments": {"city": "Tokyo"}}'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.normal_text, "Let me check. ")
+
+    def test_no_tool_call(self):
+        text = "The weather is nice today."
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 0)
+        self.assertEqual(result.normal_text, "The weather is nice today.")
+
+    def test_multiple_json_objects(self):
+        text = '<|python_tag|>{"name": "get_weather", "arguments": {"city": "Beijing"}};{"name": "search", "arguments": {"query": "restaurants"}}'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 2)
+        self.assertEqual(result.calls[0].name, "get_weather")
+        self.assertEqual(result.calls[1].name, "search")
+
+    def test_tool_call_with_multiple_arguments(self):
+        text = '<|python_tag|>{"name": "get_weather", "arguments": {"city": "London", "unit": "celsius"}}'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        args = json.loads(result.calls[0].parameters)
+        self.assertEqual(args["city"], "London")
+        self.assertEqual(args["unit"], "celsius")
+
+    # ==================== Python dict conversion Tests ====================
+
+    def test_convert_python_dict_to_json(self):
+        python_dict = "{'name': 'get_weather', 'arguments': {'city': 'Beijing'}}"
+        result = self.detector._convert_python_dict_to_json(python_dict)
+        parsed = json.loads(result)
+        self.assertEqual(parsed["name"], "get_weather")
+
+    def test_convert_invalid_string_returns_original(self):
+        invalid = "not a dict at all"
+        result = self.detector._convert_python_dict_to_json(invalid)
+        self.assertEqual(result, invalid)
+
+    # ==================== structure_info Tests ====================
+
+    def test_structure_info(self):
+        info_func = self.detector.structure_info()
+        info = info_func("get_weather")
+        self.assertIn("get_weather", info.begin)
+        self.assertIn("<|python_tag|>", info.begin)
+        self.assertEqual(info.trigger, "<|python_tag|>")
+
+    # ==================== Streaming Tests ====================
+
+    def test_streaming_single_tool_call(self):
+        detector = Llama32Detector()
+        chunks = [
+            "<|python_",
+            'tag|>{"name": "get_weather",',
+            ' "arguments": {"city": "Beijing"',
+            "}}",
+        ]
+        all_calls = []
+        for chunk in chunks:
+            result = detector.parse_streaming_increment(chunk, self.tools)
+            all_calls.extend(result.calls)
+
+        func_calls = [c for c in all_calls if c.name]
+        self.assertEqual(len(func_calls), 1)
+        self.assertEqual(func_calls[0].name, "get_weather")
+
+        full_params = "".join(c.parameters for c in all_calls if c.parameters)
+        params = json.loads(full_params)
+        self.assertEqual(params["city"], "Beijing")
+
+    def test_streaming_normal_text_before_tool(self):
+        detector = Llama32Detector()
+        result = detector.parse_streaming_increment(
+            "Let me check the weather. ", self.tools
+        )
+        self.assertEqual(result.normal_text, "Let me check the weather. ")
+        self.assertEqual(len(result.calls), 0)
+
+    def test_streaming_text_then_tool_call(self):
+        detector = Llama32Detector()
+        chunks = [
+            "I'll look that up. ",
+            '<|python_tag|>{"name": "get_weather",',
+            ' "arguments": {"city": "Tokyo", "unit": "celsius"',
+            "}}",
+        ]
+        all_calls = []
+        all_normal_text = ""
+        for chunk in chunks:
+            result = detector.parse_streaming_increment(chunk, self.tools)
+            all_calls.extend(result.calls)
+            all_normal_text += result.normal_text
+
+        self.assertEqual(all_normal_text, "I'll look that up. ")
+        func_calls = [c for c in all_calls if c.name]
+        self.assertEqual(len(func_calls), 1)
+        self.assertEqual(func_calls[0].name, "get_weather")
+        full_params = "".join(c.parameters for c in all_calls if c.parameters)
+        params = json.loads(full_params)
+        self.assertEqual(params["city"], "Tokyo")
+        self.assertEqual(params["unit"], "celsius")
+
+
+if __name__ == "__main__":
+    import unittest
+
+    unittest.main()
diff --git a/test/registered/unit/function_call/test_mistral_detector.py b/test/registered/unit/function_call/test_mistral_detector.py
new file mode 100644
index 000000000..ec49efedb
--- /dev/null
+++ b/test/registered/unit/function_call/test_mistral_detector.py
@@ -0,0 +1,224 @@
+"""Unit tests for MistralDetector — no server, no model loading."""
+
+import json
+
+from sglang.srt.entrypoints.openai.protocol import Function, Tool
+from sglang.srt.function_call.mistral_detector import MistralDetector
+from sglang.test.ci.ci_register import register_cpu_ci
+from sglang.test.test_utils import CustomTestCase
+
+register_cpu_ci(1.0, "stage-a-test-cpu")
+
+
+class TestMistralDetector(CustomTestCase):
+    def setUp(self):
+        self.tools = [
+            Tool(
+                type="function",
+                function=Function(
+                    name="get_weather",
+                    description="Get weather information",
+                    parameters={
+                        "type": "object",
+                        "properties": {
+                            "city": {"type": "string", "description": "City name"},
+                            "unit": {
+                                "type": "string",
+                                "enum": ["celsius", "fahrenheit"],
+                            },
+                        },
+                        "required": ["city"],
+                    },
+                ),
+            ),
+            Tool(
+                type="function",
+                function=Function(
+                    name="search",
+                    description="Search the web",
+                    parameters={
+                        "type": "object",
+                        "properties": {
+                            "query": {
+                                "type": "string",
+                                "description": "Search query",
+                            },
+                        },
+                        "required": ["query"],
+                    },
+                ),
+            ),
+        ]
+        self.detector = MistralDetector()
+
+    # ==================== has_tool_call Tests ====================
+
+    def test_has_tool_call_json_array_format(self):
+        text = (
+            '[TOOL_CALLS] [{"name": "get_weather", "arguments": {"city": "Beijing"}}]'
+        )
+        self.assertTrue(self.detector.has_tool_call(text))
+
+    def test_has_tool_call_compact_format(self):
+        text = '[TOOL_CALLS]get_weather[ARGS]{"city": "Beijing"}'
+        self.assertTrue(self.detector.has_tool_call(text))
+
+    def test_has_tool_call_false(self):
+        text = "The weather in Beijing is sunny today."
+        self.assertFalse(self.detector.has_tool_call(text))
+
+    # ==================== JSON Array Format Tests ====================
+
+    def test_json_array_single_tool_call(self):
+        text = (
+            '[TOOL_CALLS] [{"name": "get_weather", "arguments": {"city": "Beijing"}}]'
+        )
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.calls[0].name, "get_weather")
+        args = json.loads(result.calls[0].parameters)
+        self.assertEqual(args["city"], "Beijing")
+        self.assertEqual(result.normal_text, "")
+
+    def test_json_array_multiple_tool_calls(self):
+        text = '[TOOL_CALLS] [{"name": "get_weather", "arguments": {"city": "Beijing"}}, {"name": "search", "arguments": {"query": "restaurants"}}]'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 2)
+        self.assertEqual(result.calls[0].name, "get_weather")
+        self.assertEqual(result.calls[1].name, "search")
+
+    def test_json_array_with_leading_text(self):
+        text = 'I will check. [TOOL_CALLS] [{"name": "get_weather", "arguments": {"city": "Tokyo"}}]'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.normal_text, "I will check.")
+
+    # ==================== Compact Format Tests ====================
+
+    def test_compact_format_single_tool_call(self):
+        text = '[TOOL_CALLS]get_weather[ARGS]{"city": "Beijing"}'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.calls[0].name, "get_weather")
+        args = json.loads(result.calls[0].parameters)
+        self.assertEqual(args["city"], "Beijing")
+
+    def test_compact_format_with_leading_text(self):
+        text = 'Let me help. [TOOL_CALLS]get_weather[ARGS]{"city": "Tokyo"}'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        self.assertEqual(result.normal_text, "Let me help.")
+
+    # ==================== No Tool Call Tests ====================
+
+    def test_no_tool_call(self):
+        text = "The weather is nice today."
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 0)
+        self.assertEqual(result.normal_text, "The weather is nice today.")
+
+    # ==================== Edge Cases ====================
+
+    def test_tool_call_with_nested_json(self):
+        text = '[TOOL_CALLS] [{"name": "get_weather", "arguments": {"city": "Beijing", "options": {"detailed": true}}}]'
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 1)
+        args = json.loads(result.calls[0].parameters)
+        self.assertEqual(args["options"]["detailed"], True)
+
+    def test_json_array_with_invalid_json(self):
+        text = "[TOOL_CALLS] [not valid json]"
+        result = self.detector.detect_and_parse(text, self.tools)
+        self.assertEqual(len(result.calls), 0)
+        self.assertEqual(result.normal_text, "")
+
+    # ==================== Internal Methods Tests ====================
+
+    def test_extract_json_array(self):
+        text = (
+            '[TOOL_CALLS] [{"name": "get_weather", "arguments": {"city": "Beijing"}}]'
+        )
+        result = self.detector._extract_json_array(text)
+        self.assertIsNotNone(result)
+        parsed = json.loads(result)
+        self.assertEqual(len(parsed), 1)
+        self.assertEqual(parsed[0]["name"], "get_weather")
+
+    def test_extract_json_array_nested_brackets(self):
+        text = (
+            '[TOOL_CALLS] [{"name": "get_weather", "arguments": {"tags": ["a", "b"]}}]'
+        )
+        result = self.detector._extract_json_array(text)
+        self.assertIsNotNone(result)
+        parsed = json.loads(result)
+        self.assertEqual(parsed[0]["arguments"]["tags"], ["a", "b"])
+
+    def test_extract_json_array_no_marker(self):
+        text = "no tool calls here"
+        result = self.detector._extract_json_array(text)
+        self.assertIsNone(result)
+
+    # ==================== structure_info Tests ====================
+
+    def test_structure_info(self):
+        info_func = self.detector.structure_info()
+        info = info_func("get_weather")
+        self.assertIn("get_weather", info.begin)
+        self.assertIn("[TOOL_CALLS]", info.trigger)
+        self.assertEqual(info.end, "}]")
+
+    # ==================== Streaming Tests ====================
+
+    def test_streaming_compact_format(self):
+        detector = MistralDetector()
+        chunks = [
+            "[TOOL_",
+            "CALLS]get_weather",
+            '[ARGS]{"city": "Beijing"}',
+        ]
+        all_calls = []
+        for chunk in chunks:
+            result = detector.parse_streaming_increment(chunk, self.tools)
+            all_calls.extend(result.calls)
+
+        func_calls = [c for c in all_calls if c.name]
+        self.assertEqual(len(func_calls), 1)
+        self.assertEqual(func_calls[0].name, "get_weather")
+
+        full_params = "".join(c.parameters for c in all_calls if c.parameters)
+        params = json.loads(full_params)
+        self.assertEqual(params["city"], "Beijing")
+
+    def test_streaming_normal_text_before_tool(self):
+        detector = MistralDetector()
+        result = detector.parse_streaming_increment("Let me check. ", self.tools)
+        self.assertEqual(result.normal_text, "Let me check. ")
+        self.assertEqual(len(result.calls), 0)
+
+    def test_streaming_text_then_tool_call(self):
+        detector = MistralDetector()
+        chunks = [
+            "Sure! ",
+            "[TOOL_CALLS]get_weather",
+            '[ARGS]{"city": "Tokyo"}',
+        ]
+        all_calls = []
+        all_normal_text = ""
+        for chunk in chunks:
+            result = detector.parse_streaming_increment(chunk, self.tools)
+            all_calls.extend(result.calls)
+            all_normal_text += result.normal_text
+
+        self.assertEqual(all_normal_text, "Sure! ")
+        func_calls = [c for c in all_calls if c.name]
+        self.assertEqual(len(func_calls), 1)
+        self.assertEqual(func_calls[0].name, "get_weather")
+        full_params = "".join(c.parameters for c in all_calls if c.parameters)
+        params = json.loads(full_params)
+        self.assertEqual(params["city"], "Tokyo")
+
+
+if __name__ == "__main__":
+    import unittest
+
+    unittest.main()