| 1 | # SPDX-License-Identifier: Apache-2.0 |
| 2 | # SPDX-FileCopyrightText: Copyright contributors to the vLLM project |
| 3 | """Reasoning extraction, reasoning-end gating and parser selection for the |
| 4 | unified Cohere Command parser.""" |
| 5 | |
| 6 | from __future__ import annotations |
| 7 | |
| 8 | from dataclasses import dataclass |
| 9 | |
| 10 | import pytest |
| 11 | |
| 12 | from vllm.entrypoints.openai.chat_completion.protocol import ChatCompletionRequest |
| 13 | from vllm.parser import ParserManager |
| 14 | from vllm.reasoning.cohere_command_reasoning_parser import ( |
| 15 | CohereCommand3ReasoningParser, |
| 16 | CohereCommand4ReasoningParser, |
| 17 | ) |
| 18 | |
| 19 | from .utils import make_parser, stream_parser |
| 20 | |
| 21 | |
| 22 | @dataclass |
| 23 | class ReasoningCase: |
| 24 | parser_name: str |
| 25 | model_output: str |
| 26 | expected_reasoning: str | None |
| 27 | expected_content: str | None |
| 28 | |
| 29 | |
| 30 | REASONING_CASES = [ |
| 31 | pytest.param( |
| 32 | ReasoningCase( |
| 33 | parser_name="cohere_command3", |
| 34 | model_output="""\ |
| 35 | <|START_THINKING|> i will call foo with query1<|END_THINKING|><|START_ACTION|> |
| 36 | [ |
| 37 | {"tool_call_id": "0", "tool_name": "foo", "parameters": {"query": "query1"}} |
| 38 | ] |
| 39 | <|END_ACTION|>""", |
| 40 | expected_reasoning="i will call foo with query1", |
| 41 | expected_content=None, |
| 42 | ), |
| 43 | id="cmd3-single_tool_call", |
| 44 | ), |
| 45 | pytest.param( |
| 46 | ReasoningCase( |
| 47 | parser_name="cohere_command4", |
| 48 | model_output="""\ |
| 49 | <|START_THINKING|> i will call foo with query1<|END_THINKING|><|START_ACTION|> |
| 50 | [ |
| 51 | {"tool_call_id": "0", "tool_name": "foo", "parameters": {"query": "query1"}} |
| 52 | ] |
| 53 | <|END_ACTION|>""", |
| 54 | expected_reasoning="i will call foo with query1", |
| 55 | expected_content=None, |
| 56 | ), |
| 57 | id="cmd4-single_tool_call", |
| 58 | ), |
| 59 | pytest.param( |
| 60 | ReasoningCase( |
| 61 | parser_name="cohere_command3", |
| 62 | model_output="""\ |
| 63 | <|START_THINKING|>This is a rainbow <co>emoji: 🌈</co: 0:[1]><|END_THINKING|> |
| 64 | <|START_RESPONSE|>foo <co>bar</co: 0:[1,2],1:[3,4]><|END_RESPONSE|>""", |
| 65 | expected_reasoning="This is a rainbow emoji: 🌈", |
| 66 | expected_content="foo bar", |
| 67 | ), |
| 68 | id="cmd3-citations_with_emoji", |
| 69 | ), |
| 70 | pytest.param( |
| 71 | ReasoningCase( |
| 72 | parser_name="cohere_command4", |
| 73 | model_output="""\ |
| 74 | <|START_THINKING|>This is a rainbow <co>emoji: 🌈</co: 0:[1]><|END_THINKING|> |
| 75 | <|START_RESPONSE|>foo <co>bar</co: 0:[1,2],1:[3,4]><|END_RESPONSE|>""", |
| 76 | expected_reasoning="This is a rainbow emoji: 🌈", |
| 77 | expected_content="foo bar", |
| 78 | ), |
| 79 | id="cmd4-citations_with_emoji", |
| 80 | ), |
| 81 | ] |
| 82 | |
| 83 | |
| 84 | @pytest.mark.parametrize("case", REASONING_CASES) |
| 85 | class TestExtractReasoning: |
| 86 | def test_nonstreaming(self, tokenizer, request_obj, case: ReasoningCase): |
| 87 | parser = make_parser(tokenizer, case.parser_name) |
| 88 | reasoning, content, tool_calls = parser.parse( |
| 89 | case.model_output, request_obj, enable_auto_tools=True |
| 90 | ) |
| 91 | assert reasoning == case.expected_reasoning |
| 92 | assert content == case.expected_content |
| 93 | # No tools on the request, so any tool call is dropped, not surfaced. |
| 94 | assert not tool_calls |
| 95 | |
| 96 | def test_streaming(self, tokenizer, request_obj, case: ReasoningCase): |
| 97 | parser = make_parser(tokenizer, case.parser_name) |
| 98 | deltas = stream_parser(parser, request_obj, tokenizer, case.model_output) |
| 99 | |
| 100 | reasoning = "".join(d.reasoning for d in deltas if d.reasoning) or None |
| 101 | content = "".join(d.content for d in deltas if d.content) or None |
| 102 | assert reasoning == case.expected_reasoning |
| 103 | assert content == case.expected_content |
| 104 | assert all(not d.tool_calls for d in deltas) |
| 105 | |
| 106 | |
| 107 | class TestFramingTokensStripped: |
| 108 | @pytest.mark.parametrize( |
| 109 | ("parser_name", "content_tags"), |
| 110 | [ |
| 111 | pytest.param( |
| 112 | "cohere_command4", ("<|START_TEXT|>", "<|END_TEXT|>"), id="cmd4" |
| 113 | ), |
| 114 | pytest.param( |
| 115 | "cohere_command3", ("<|START_RESPONSE|>", "<|END_RESPONSE|>"), id="cmd3" |
| 116 | ), |
| 117 | ], |
| 118 | ) |
| 119 | @pytest.mark.parametrize("chunk_size", [1, 4], ids=["per_token", "batched"]) |
| 120 | @pytest.mark.parametrize("with_tools", [False, True], ids=["no_tools", "tools"]) |
| 121 | def test_content_framing_tokens_stripped( |
| 122 | self, tokenizer, parser_name, content_tags, chunk_size, with_tools |
| 123 | ): |
| 124 | parser = make_parser(tokenizer, parser_name) |
| 125 | tools = [{"type": "function", "function": {"name": "foo"}}] |
| 126 | request = ChatCompletionRequest( |
| 127 | messages=[], model="test-model", tools=tools if with_tools else None |
| 128 | ) |
| 129 | parser.adjust_request(request) |
| 130 | |
| 131 | start_tag, end_tag = content_tags |
| 132 | generation = ( |
| 133 | f"<|START_THINKING|>Think deeply. The user greets us.<|END_THINKING|>" |
| 134 | f"{start_tag}I'm doing well, thank you{end_tag}" |
| 135 | ) |
| 136 | deltas = stream_parser(parser, request, tokenizer, generation, chunk_size) |
| 137 | |
| 138 | assert "".join(d.reasoning or "" for d in deltas) == ( |
| 139 | "Think deeply. The user greets us." |
| 140 | ) |
| 141 | assert not any(d.tool_calls for d in deltas) |
| 142 | assert "".join(d.content or "" for d in deltas) == "I'm doing well, thank you" |
| 143 | |
| 144 | |
| 145 | class TestIsReasoningEnd: |
| 146 | @pytest.mark.parametrize( |
| 147 | "parser_cls", |
| 148 | [CohereCommand3ReasoningParser, CohereCommand4ReasoningParser], |
| 149 | ids=["cmd3", "cmd4"], |
| 150 | ) |
| 151 | def test_is_reasoning_end(self, tokenizer, parser_cls): |
| 152 | parser = parser_cls(tokenizer) |
| 153 | start_id = tokenizer.convert_tokens_to_ids("<|START_THINKING|>") |
| 154 | end_id = tokenizer.convert_tokens_to_ids("<|END_THINKING|>") |
| 155 | chatbot_id = tokenizer.convert_tokens_to_ids("<|CHATBOT_TOKEN|>") |
| 156 | content_ids = [99, 100] |
| 157 | |
| 158 | # Generation-only tokens have no chatbot marker, so the whole sequence |
| 159 | # is considered. |
| 160 | assert parser.is_reasoning_end([end_id]) |
| 161 | assert parser.is_reasoning_end([start_id, *content_ids, end_id]) |
| 162 | assert not parser.is_reasoning_end([start_id, *content_ids]) |
| 163 | |
| 164 | # Full prompt/history tokens are scoped to the latest chatbot marker, |
| 165 | # so stray thinking tokens from the preamble or previous turns are ignored. |
| 166 | assert not parser.is_reasoning_end([start_id, end_id, chatbot_id, *content_ids]) |
| 167 | assert parser.is_reasoning_end( |
| 168 | [start_id, end_id, chatbot_id, start_id, *content_ids, end_id] |
| 169 | ) |
| 170 | |
| 171 | |
| 172 | @pytest.mark.parametrize("parser_name", ["cohere_command3", "cohere_command4"]) |
| 173 | def test_count_reasoning_tokens(tokenizer, parser_name): |
| 174 | parser = make_parser(tokenizer, parser_name) |
| 175 | start = tokenizer.convert_tokens_to_ids("<|START_THINKING|>") |
| 176 | end = tokenizer.convert_tokens_to_ids("<|END_THINKING|>") |
| 177 | |
| 178 | assert parser.count_reasoning_tokens([99, start, 11, 12, end, 100]) == 2 |
| 179 | assert parser.count_reasoning_tokens([end, start, 1, start, 2, end, 3, end]) == 3 |
| 180 | assert parser.count_reasoning_tokens([start, 1, 2]) == 2 |
| 181 | assert parser.count_reasoning_tokens([1, 2, end]) == 0 |
| 182 | |
| 183 | |
| 184 | class TestParserSelection: |
| 185 | @pytest.mark.parametrize("with_tool_parser", [True, False]) |
| 186 | def test_adjust_request_keeps_framing_tokens(self, tokenizer, with_tool_parser): |
| 187 | """Melody needs the special tokens, with or without a tool parser.""" |
| 188 | cls = ParserManager.get_parser( |
| 189 | "cohere_command4" if with_tool_parser else None, |
| 190 | "cohere_command4", |
| 191 | enable_auto_tools=True, |
| 192 | ) |
| 193 | request = ChatCompletionRequest(messages=[], model="m") |
| 194 | assert request.skip_special_tokens |
| 195 | cls(tokenizer).adjust_request(request) |
| 196 | assert request.skip_special_tokens is False |
| 197 | |
| 198 | def test_non_cohere_selection_does_not_import_melody_parser(self, monkeypatch): |
| 199 | """``cohere_melody`` is optional; other parsers must not depend on it.""" |
| 200 | import sys |
| 201 | |
| 202 | monkeypatch.setitem(sys.modules, "vllm.parser.cohere_command", None) |
| 203 | assert ParserManager.get_parser("hermes", "deepseek_r1", True) is not None |