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[Bugfix]: Reasoning output bug according to the chat template change #13025

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Merged
merged 2 commits into from
Feb 11, 2025
Merged

[Bugfix]: Reasoning output bug according to the chat template change #13025

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ef7e1ec
chore: Keep compatibility
gaocegege Feb 11, 2025
11b6b4b
chore: Add two more test cases and speed it up
gaocegege Feb 11, 2025
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8 changes: 4 additions & 4 deletions examples/online_serving/openai_chat_completion_with_reasoning.py
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Original file line number Diff line number Diff line change
Expand Up @@ -36,8 +36,8 @@
reasoning_content = response.choices[0].message.reasoning_content
content = response.choices[0].message.content

print("reasoning_content:", reasoning_content)
print("content:", content)
print("reasoning_content for Round 1:", reasoning_content)
print("content for Round 1:", content)

# Round 2
messages.append({"role": "assistant", "content": content})
Expand All @@ -50,5 +50,5 @@
reasoning_content = response.choices[0].message.reasoning_content
content = response.choices[0].message.content

print("reasoning_content:", reasoning_content)
print("content:", content)
print("reasoning_content for Round 2:", reasoning_content)
print("content for Round 2:", content)
108 changes: 90 additions & 18 deletions tests/entrypoints/openai/reasoning_parsers/test_deepseekr1_reasoning_parser.py
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Original file line number Diff line number Diff line change
Expand Up @@ -15,32 +15,62 @@
end_token = "</think>"

SIMPLE_REASONING = {
"output": "<think>This is a reasoning section</think>This is the rest",
"output": "This is a reasoning section</think>This is the rest",
"reasoning_content": "This is a reasoning section",
"content": "This is the rest",
}
COMPLETE_REASONING = {
"output": "<think>This is a reasoning section</think>",
"output": "This is a reasoning section</think>",
"reasoning_content": "This is a reasoning section",
"content": None,
}
NO_REASONING = {
"output": "This is a reasoning section",
"output": "This is content",
"reasoning_content": None,
"content": "This is a reasoning section",
"content": "This is content",
}
NO_REASONING_STREAMING = {
"output": "This is a reasoning section",
"reasoning_content": "This is a reasoning section",
"content": None,
}
MULTIPLE_LINES = {
"output": "<think>This\nThat</think>This is the rest\nThat",
"output": "This\nThat</think>This is the rest\nThat",
"reasoning_content": "This\nThat",
"content": "This is the rest\nThat",
}
SHORTEST_REASONING_NO_STREAMING = {
"output": "<think></think>This is the rest",
"output": "</think>This is the rest",
"reasoning_content": "",
"content": "This is the rest",
}
SHORTEST_REASONING = {
"output": "<think></think>This is the rest",
"output": "</think>This is the rest",
"reasoning_content": None,
"content": "This is the rest",
}
REASONING_WITH_THINK = {
"output": "<think>This is a reasoning section</think>This is the rest",
"reasoning_content": "This is a reasoning section",
"content": "This is the rest",
}
COMPLETE_REASONING_WITH_THINK = {
"output": "<think>This is a reasoning section</think>",
"reasoning_content": "This is a reasoning section",
"content": None,
}
MULTIPLE_LINES_WITH_THINK = {
"output": "<think>This\nThat</think>This is the rest\nThat",
"reasoning_content": "This\nThat",
"content": "This is the rest\nThat",
}
SHORTEST_REASONING_NO_STREAMING_WITH_THINK = {
"output": "</think>This is the rest",
"reasoning_content": "",
"content": "This is the rest",
}
SHORTEST_REASONING_WITH_THINK = {
"output": "</think>This is the rest",
"reasoning_content": None,
"content": "This is the rest",
}
Expand All @@ -49,37 +79,37 @@
pytest.param(
False,
SIMPLE_REASONING,
id="simple_streaming",
id="simple_reasoning",
),
pytest.param(
True,
SIMPLE_REASONING,
id="simple_streaming",
id="simple_reasoning_streaming",
),
pytest.param(
False,
COMPLETE_REASONING,
id="complete_streaming",
id="complete_reasoning",
),
pytest.param(
True,
COMPLETE_REASONING,
id="complete_streaming",
id="complete_reasoning_streaming",
),
pytest.param(
False,
NO_REASONING,
id="no_streaming",
id="no_reasoning_token",
),
pytest.param(
True,
NO_REASONING,
id="no_streaming",
NO_REASONING_STREAMING,
id="no_reasoning_token_streaming",
),
pytest.param(
False,
MULTIPLE_LINES,
id="multiple_lines_streaming",
id="multiple_lines",
),
pytest.param(
True,
Expand All @@ -89,23 +119,65 @@
pytest.param(
True,
SHORTEST_REASONING,
id="shortest_streaming",
id="shortest",
),
pytest.param(
False,
SHORTEST_REASONING_NO_STREAMING,
id="shortest_streaming",
),
pytest.param(
False,
REASONING_WITH_THINK,
id="reasoning_with_think",
),
pytest.param(
True,
REASONING_WITH_THINK,
id="reasoning_with_think_streaming",
),
pytest.param(
False,
COMPLETE_REASONING_WITH_THINK,
id="complete_reasoning_with_think",
),
pytest.param(
True,
COMPLETE_REASONING_WITH_THINK,
id="complete_reasoning_with_think_streaming",
),
pytest.param(
False,
MULTIPLE_LINES_WITH_THINK,
id="multiple_lines_with_think",
),
pytest.param(
True,
MULTIPLE_LINES_WITH_THINK,
id="multiple_lines_with_think_streaming",
),
pytest.param(
False,
SHORTEST_REASONING_NO_STREAMING_WITH_THINK,
id="shortest_with_think",
),
pytest.param(
True,
SHORTEST_REASONING_WITH_THINK,
id="shortest_with_think_streaming",
),
]

# Global tokenizer initialization to avoid repeated loading
tokenizer = AutoTokenizer.from_pretrained("facebook/opt-125m")
tokenizer.add_tokens([start_token, end_token])


@pytest.mark.parametrize("streaming, param_dict", TEST_CASES)
def test_reasoning(
streaming: bool,
param_dict: dict,
):
tokenizer = AutoTokenizer.from_pretrained("facebook/opt-125m")
tokenizer.add_tokens([start_token, end_token])
output = tokenizer.tokenize(param_dict["output"])
# decode everything to tokens
output_tokens: List[str] = [
Expand Down
58 changes: 35 additions & 23 deletions vllm/entrypoints/openai/reasoning_parsers/deepseek_r1_reasoning_parser.py
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Original file line number Diff line number Diff line change
Expand Up @@ -67,6 +67,8 @@ def extract_reasoning_content_streaming(
]):
return None

# Check if <think> is present in previous or delta.
# Keep compatibility with models that don't generate <think> tokens.
if self.think_start_token_id in previous_token_ids:
if self.think_end_token_id in delta_token_ids:
# <think> in previous, </think> in delta,
Expand All @@ -85,7 +87,6 @@ def extract_reasoning_content_streaming(
# reasoning content continues
return DeltaMessage(reasoning_content=delta_text)
elif self.think_start_token_id in delta_token_ids:
logger.info(delta_text)
if self.think_end_token_id in delta_token_ids:
# <think> in delta, </think> in delta, extract reasoning content
start_index = delta_text.find(self.think_start_token)
Expand All @@ -101,35 +102,46 @@ def extract_reasoning_content_streaming(
# reasoning content continues
return DeltaMessage(reasoning_content=delta_text)
else:
# No <think> in previous or delta, reasoning content continues.
return DeltaMessage(content=delta_text)
# No <think> in previous or delta, also need to check for </think>.
# Because the model may have generated </think> without <think>
# Ref https://huggingface.co/deepseek-ai/DeepSeek-R1/commit/8a58a132790c9935686eb97f042afa8013451c9f
if self.think_end_token_id in delta_token_ids:
# </think> in delta with more tokens,
# extract reasoning content and content
end_index = delta_text.find(self.think_end_token)
reasoning_content = delta_text[:end_index]
content = delta_text[end_index + len(self.think_end_token):]
return DeltaMessage(reasoning_content=reasoning_content,
content=content if content else None)
elif self.think_end_token_id in previous_token_ids:
# </think> in previous, thinking content ends
return DeltaMessage(content=delta_text)
else:
# no </think> in previous or delta, reasoning content continues
return DeltaMessage(reasoning_content=delta_text)

def extract_reasoning_content(
self, model_output: str, request: ChatCompletionRequest
) -> Tuple[Optional[str], Optional[str]]:

# Check if the model output contains the <think> tokens.
if (self.think_start_token not in model_output
or self.think_end_token not in model_output):
# DeepSeek R1 doesn't generate <think> now.
# Thus we assume the reasoning content is always at the start.
# Ref https://huggingface.co/deepseek-ai/DeepSeek-R1/commit/8a58a132790c9935686eb97f042afa8013451c9f
if self.think_end_token not in model_output:
return None, model_output
else:
# Add a start token if it's missing to keep compatibility.
if self.think_start_token not in model_output:
model_output = f"{self.think_start_token}{model_output}"
# Use a regex to find the reasoning content
reasoning_content = self.reasoning_regex.findall(model_output)[0]

# Remove the reasoning content from the model output
# Although deepseek's <think> token is always at the
# beginning of the line, we cannot guarantee that the
# other models will follow this convention.
# Therefore, we need to add :start_index.
start_index = model_output.find(self.think_start_token)
if start_index != -1:
end_index = start_index + len(
f"{self.think_start_token}{reasoning_content}{self.think_end_token}"
)
model_output = model_output[:start_index] + \
model_output[end_index:]

if len(model_output) == 0:
return reasoning_content, None

return reasoning_content, model_output
end_index = len(
f"{self.think_start_token}{reasoning_content}{self.think_end_token}"
)
final_output = model_output[end_index:]

if len(final_output) == 0:
return reasoning_content, None

return reasoning_content, final_output