vllm/tests/async_engine/test_chat_template.py
Cyrus Leung 66d617e343
[Frontend] Gracefully handle missing chat template and fix CI failure (#7238)
Co-authored-by: Roger Wang <ywang@roblox.com>
2024-08-07 09:12:05 +00:00

101 lines
3.1 KiB
Python

import pytest
from vllm.entrypoints.chat_utils import apply_chat_template, load_chat_template
from vllm.entrypoints.openai.protocol import ChatCompletionRequest
from vllm.transformers_utils.tokenizer import get_tokenizer
from ..utils import VLLM_PATH
chatml_jinja_path = VLLM_PATH / "examples/template_chatml.jinja"
assert chatml_jinja_path.exists()
# Define models, templates, and their corresponding expected outputs
MODEL_TEMPLATE_GENERATON_OUTPUT = [
("facebook/opt-125m", chatml_jinja_path, True, """<|im_start|>user
Hello<|im_end|>
<|im_start|>assistant
Hi there!<|im_end|>
<|im_start|>user
What is the capital of<|im_end|>
<|im_start|>assistant
"""),
("facebook/opt-125m", chatml_jinja_path, False, """<|im_start|>user
Hello<|im_end|>
<|im_start|>assistant
Hi there!<|im_end|>
<|im_start|>user
What is the capital of""")
]
TEST_MESSAGES = [
{
'role': 'user',
'content': 'Hello'
},
{
'role': 'assistant',
'content': 'Hi there!'
},
{
'role': 'user',
'content': 'What is the capital of'
},
]
def test_load_chat_template():
# Testing chatml template
template_content = load_chat_template(chat_template=chatml_jinja_path)
# Test assertions
assert template_content is not None
# Hard coded value for template_chatml.jinja
assert template_content == """{% for message in messages %}{{'<|im_start|>' + message['role'] + '\\n' + message['content']}}{% if (loop.last and add_generation_prompt) or not loop.last %}{{ '<|im_end|>' + '\\n'}}{% endif %}{% endfor %}
{% if add_generation_prompt and messages[-1]['role'] != 'assistant' %}{{ '<|im_start|>assistant\\n' }}{% endif %}""" # noqa: E501
def test_no_load_chat_template_filelike():
# Testing chatml template
template = "../../examples/does_not_exist"
with pytest.raises(ValueError, match="looks like a file path"):
load_chat_template(chat_template=template)
def test_no_load_chat_template_literallike():
# Testing chatml template
template = "{{ messages }}"
template_content = load_chat_template(chat_template=template)
assert template_content == template
@pytest.mark.parametrize(
"model,template,add_generation_prompt,expected_output",
MODEL_TEMPLATE_GENERATON_OUTPUT)
def test_get_gen_prompt(model, template, add_generation_prompt,
expected_output):
# Initialize the tokenizer
tokenizer = get_tokenizer(tokenizer_name=model)
template_content = load_chat_template(chat_template=template)
# Create a mock request object using keyword arguments
mock_request = ChatCompletionRequest(
model=model,
messages=TEST_MESSAGES,
add_generation_prompt=add_generation_prompt)
# Call the function and get the result
result = apply_chat_template(
tokenizer,
conversation=mock_request.messages,
chat_template=mock_request.chat_template or template_content,
add_generation_prompt=mock_request.add_generation_prompt,
)
# Test assertion
assert result == expected_output, (
f"The generated prompt does not match the expected output for "
f"model {model} and template {template}")