# ruff: noqa: E501
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from __future__ import annotations
import json
from enum import Enum
from typing import TYPE_CHECKING, Any
import jsonschema
import pytest
import regex as re
from pydantic import BaseModel
from tests.reasoning.utils import run_reasoning_extraction
from vllm.entrypoints.llm import LLM
from vllm.outputs import RequestOutput
from vllm.platforms import current_platform
from vllm.reasoning.abs_reasoning_parsers import ReasoningParserManager
from vllm.sampling_params import GuidedDecodingParams, SamplingParams
if TYPE_CHECKING:
from vllm.config import TokenizerMode
NGRAM_SPEC_CONFIG = {
"model": "[ngram]",
"num_speculative_tokens": 5,
"prompt_lookup_max": 5,
"prompt_lookup_min": 1,
}
EAGLE_SPEC_CONFIG = {
"method": "eagle",
"model": "yuhuili/EAGLE-LLaMA3.1-Instruct-8B",
"num_speculative_tokens": 5,
}
PARAMS_MODELS_BACKENDS_TOKENIZER_MODE = [
("mistralai/Ministral-8B-Instruct-2410", "xgrammar", "auto", None),
("mistralai/Ministral-8B-Instruct-2410", "guidance", "auto", None),
("mistralai/Ministral-8B-Instruct-2410", "xgrammar", "mistral", None),
("Qwen/Qwen2.5-1.5B-Instruct", "xgrammar", "auto", None),
#FIXME: This test is flaky on CI thus disabled
#("Qwen/Qwen2.5-1.5B-Instruct", "guidance", "auto"),
("mistralai/Ministral-8B-Instruct-2410", "guidance", "auto",
NGRAM_SPEC_CONFIG),
("Qwen/Qwen2.5-1.5B-Instruct", "xgrammar", "auto", NGRAM_SPEC_CONFIG),
("meta-llama/Meta-Llama-3.1-8B-Instruct", "xgrammar", "auto",
EAGLE_SPEC_CONFIG)
]
PARAMS_MODELS_TOKENIZER_MODE = [
("mistralai/Ministral-8B-Instruct-2410", "auto"),
("Qwen/Qwen2.5-1.5B-Instruct", "auto"),
]
class CarType(str, Enum):
sedan = "sedan"
suv = "SUV"
truck = "Truck"
coupe = "Coupe"
class CarDescription(BaseModel):
brand: str
model: str
car_type: CarType
def _load_json(s: str, backend: str) -> str:
if backend != "xgrammar":
return json.loads(s)
# xgrammar specific workarounds
# https://github.com/mlc-ai/xgrammar/issues/286
s = re.sub(r'[\x00-\x1F\x7F-\xFF]', '', s)
return json.loads(s)
@pytest.mark.skip_global_cleanup
@pytest.mark.parametrize(
"model_name, guided_decoding_backend, tokenizer_mode, speculative_config",
PARAMS_MODELS_BACKENDS_TOKENIZER_MODE)
def test_structured_output(
monkeypatch: pytest.MonkeyPatch,
sample_json_schema: dict[str, Any],
unsupported_json_schema: dict[str, Any],
sample_sql_ebnf: str,
sample_sql_lark: str,
sample_regex: str,
sample_guided_choice: str,
guided_decoding_backend: str,
tokenizer_mode: str,
model_name: str,
speculative_config: dict[str, Any],
):
monkeypatch.setenv("VLLM_USE_V1", "1")
if current_platform.is_tpu() and speculative_config:
pytest.skip("TPU does not support speculative decoding")
# Don't use eager execution on TPUs because we want to test for no
# recompilation at runtime
enforce_eager = bool(not current_platform.is_tpu())
# Use a single LLM instance for several scenarios to
# speed up the test suite.
llm = LLM(model=model_name,
enforce_eager=enforce_eager,
max_model_len=1024,
guided_decoding_backend=guided_decoding_backend,
guided_decoding_disable_any_whitespace=True,
tokenizer_mode=tokenizer_mode,
speculative_config=speculative_config)
#
# Test 1: Generate JSON output based on a provided schema
#
sampling_params = SamplingParams(
temperature=1.0,
max_tokens=4096,
guided_decoding=GuidedDecodingParams(json=sample_json_schema))
outputs = llm.generate(prompts=[
(f"Give an example JSON for an employee profile that fits this "
f"schema. Make the response as short as possible. Schema: "
f"{sample_json_schema}")
] * 2,
sampling_params=sampling_params,
use_tqdm=True)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
prompt = output.prompt
generated_text = output.outputs[0].text
assert generated_text is not None
assert "\n" not in generated_text
print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
output_json = json.loads(generated_text)
jsonschema.validate(instance=output_json, schema=sample_json_schema)
#
# Test 2: Generate JSON object without a schema
#
sampling_params = SamplingParams(
temperature=1.0,
max_tokens=4096,
n=2,
guided_decoding=GuidedDecodingParams(json_object=True))
outputs = llm.generate(
prompts=("Generate a JSON object with curly braces for a person with "
"name and age fields for John Smith who is 31 years old. "
"Make the response as short as possible."),
sampling_params=sampling_params,
use_tqdm=True)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
for i in range(2):
generated_text = output.outputs[i].text
print(generated_text)
assert generated_text is not None
# Parse to verify it is a valid JSON object
parsed_json = json.loads(generated_text)
assert isinstance(parsed_json, dict)
#
# Test 3: test a jsonschema incompatible with xgrammar
#
sampling_params = SamplingParams(
temperature=1.0,
max_tokens=4096,
guided_decoding=GuidedDecodingParams(json=unsupported_json_schema))
if guided_decoding_backend.startswith("xgrammar"):
with pytest.raises(ValueError,
match="The provided JSON schema contains features "
"not supported by xgrammar."):
llm.generate(
prompts=[(f"Give an example JSON for an employee profile that "
f"fits this schema: {unsupported_json_schema}. "
f"Make the response as short as possible.")] * 2,
sampling_params=sampling_params,
use_tqdm=True)
else:
outputs = llm.generate(prompts=(
"Give an example JSON object for a grade "
"that fits this schema: "
f"{unsupported_json_schema}. Make the response as short as "
"possible."),
sampling_params=sampling_params,
use_tqdm=True)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
generated_text = output.outputs[0].text
assert generated_text is not None
print(generated_text)
# Parse to verify it is valid JSON
parsed_json = json.loads(generated_text)
assert isinstance(parsed_json, dict)
#
# Test 4: Generate SQL statement using EBNF grammar
#
sampling_params = SamplingParams(
temperature=0.8,
top_p=0.95,
max_tokens=1000,
guided_decoding=GuidedDecodingParams(grammar=sample_sql_ebnf))
outputs = llm.generate(
prompts=(
"Generate a sql statement that selects col_1 from "
"table_1 where it is equal to 1. Make the response as short as "
"possible."),
sampling_params=sampling_params,
use_tqdm=True,
)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
prompt = output.prompt
generated_text = output.outputs[0].text
assert generated_text is not None
# remove spaces for comparison b/c we removed them in the grammar
ground_truth = "SELECT col_1 from table_1 where col_1 = 1".replace(
" ", "")
assert generated_text.strip() == ground_truth
print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
#
# Test 5: Generate SQL statement using Lark grammar
#
sampling_params = SamplingParams(
temperature=0.8,
top_p=0.95,
max_tokens=1000,
guided_decoding=GuidedDecodingParams(grammar=sample_sql_lark))
outputs = llm.generate(
prompts=(
"Generate a sql statement that selects col_1 from "
"table_1 where it is equal to 1. Make the response as short as "
"possible."),
sampling_params=sampling_params,
use_tqdm=True,
)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
prompt = output.prompt
generated_text = output.outputs[0].text
assert generated_text is not None
# use Lark to parse the output, and make sure it's a valid parse tree
from lark import Lark
parser = Lark(sample_sql_lark)
parser.parse(generated_text)
# remove spaces for comparison b/c we removed them in the grammar
ground_truth = "SELECT col_1 from table_1 where col_1 = 1".replace(
" ", "")
assert generated_text.strip() == ground_truth
print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
#
# Test 6: Test invalid grammar input
#
sampling_params = SamplingParams(
temperature=0.8,
top_p=0.95,
max_tokens=1000,
guided_decoding=GuidedDecodingParams(grammar="not a grammar"))
with pytest.raises(ValueError, match="Failed to convert the grammar "):
llm.generate(
prompts=(
"Generate a sql statement that selects col_1 from "
"table_1 where it is equal to 1. Make the response as short "
"as possible."),
sampling_params=sampling_params,
use_tqdm=True,
)
#
# Test 7: Generate text based on a regex pattern
#
sampling_params = SamplingParams(
temperature=0.8,
top_p=0.95,
guided_decoding=GuidedDecodingParams(regex=sample_regex))
outputs = llm.generate(
prompts=[
(f"Give an example IPv4 address with this regex: {sample_regex}. "
f"Make the response as short as possible.")
] * 2,
sampling_params=sampling_params,
use_tqdm=True,
)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
prompt = output.prompt
generated_text = output.outputs[0].text
print(generated_text)
assert generated_text is not None
assert re.fullmatch(sample_regex, generated_text) is not None
print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
#
# Test 8: Generate text based on a choices
#
sampling_params = SamplingParams(
temperature=0.8,
top_p=0.95,
guided_decoding=GuidedDecodingParams(choice=sample_guided_choice))
outputs = llm.generate(
prompts=("The best language for type-safe systems programming is "
"(Make the response as short as possible.) "),
sampling_params=sampling_params,
use_tqdm=True)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
prompt = output.prompt
generated_text = output.outputs[0].text
print(generated_text)
assert generated_text is not None
assert generated_text in sample_guided_choice
print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
#
# Test 9: Generate structured output using a Pydantic model with an enum
#
json_schema = CarDescription.model_json_schema()
sampling_params = SamplingParams(
temperature=1.0,
max_tokens=1000,
guided_decoding=GuidedDecodingParams(json=json_schema))
outputs = llm.generate(prompts=(
"Generate a JSON with the brand, model and car_type of the most "
"iconic car from the 90's. Make the response as short as "
"possible."),
sampling_params=sampling_params,
use_tqdm=True)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
prompt = output.prompt
generated_text = output.outputs[0].text
assert generated_text is not None
print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
output_json = json.loads(generated_text)
jsonschema.validate(instance=output_json, schema=json_schema)
#
# Test 10: Generate structured with minLength and maxLength
#
min_length = 50
max_length = 50
json_schema = {
"type": "object",
"properties": {
"description": {
"type": "string",
"maxLength": max_length,
"minLength": min_length
}
},
"required": ["description"],
"additionalProperties": False
}
sampling_params = SamplingParams(
temperature=1.0,
max_tokens=4096,
guided_decoding=GuidedDecodingParams(json=json_schema))
outputs = llm.generate(
prompts=("Generate a description of a frog using 50 characters. "
"Make the response as short as possible."),
sampling_params=sampling_params,
use_tqdm=True)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
prompt = output.prompt
generated_text = output.outputs[0].text
assert generated_text is not None
print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
output_json = json.loads(generated_text)
jsonschema.validate(instance=output_json, schema=json_schema)
#
# Test 11: Generate structured output using structural_tag format
#
structural_tag_config = {
"type":
"structural_tag",
"structures": [{
"begin": "",
"schema": {
"type": "object",
"properties": {
"city": {
"type": "string"
}
},
"additionalProperties": False
},
"end": ""
}],
"triggers": ["{parameters}{end_tag}
where
start_tag => ` a JSON dict with the function argument name
as key and function argument value as value.
end_tag => ``
Here is an example,
{"example_name": "example_value"}
Reminder:
- Function calls MUST follow the specified format
- Required parameters MUST be specified
- Only call one function at a time
- Put the entire function call reply on one line
- Always add your sources when using search results to answer the user query
You are a helpful assistant.
Given the previous instructions, what is the weather in New York City? \
Make the response as short as possible.
"""
# Change this once other backends support structural_tag
outputs = llm.generate(prompts=prompt,
sampling_params=sampling_params,
use_tqdm=True)
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
generated_text = output.outputs[0].text
assert generated_text is not None
# Search for function call pattern in the response
function_call_pattern = r'(.*?)'
matches = re.findall(function_call_pattern, generated_text)
if not matches:
print(f"Warning: No function calls found in response: "
f"{generated_text!r}")
continue
# Take the first function call if multiple are found
json_str = matches[0]
try:
json_content = json.loads(json_str)
assert "city" in json_content
assert isinstance(json_content["city"], str)
print(f"Found valid function call: {generated_text!r}")
except (json.JSONDecodeError, AssertionError) as e:
pytest.fail("Invalid function call format: "
f"{generated_text!r}\nError: {str(e)}")
@pytest.mark.skip_global_cleanup
@pytest.mark.parametrize(
"model_name, guided_decoding_backend, tokenizer_mode, reasoning_parser, speculative_config", # noqa: E501
[
("deepseek-ai/DeepSeek-R1-Distill-Qwen-1.5B", "xgrammar", "auto",
"deepseek_r1", NGRAM_SPEC_CONFIG),
("Qwen/Qwen3-1.7B", "xgrammar", "auto", "deepseek_r1", None),
],
)
def test_structured_output_with_reasoning_matrices(
monkeypatch: pytest.MonkeyPatch,
guided_decoding_backend: str,
tokenizer_mode: TokenizerMode,
reasoning_parser: str,
model_name: str,
speculative_config: dict[str, Any] | None,
):
monkeypatch.setenv("VLLM_USE_V1", "1")
if current_platform.is_tpu() and speculative_config:
pytest.skip("TPU does not support speculative decoding")
# Use a single LLM instance for several scenarios to
# speed up the test suite.
llm = LLM(
model=model_name,
# Don't use eager execution on TPUs because we want to test for no
# recompilation at runtime
enforce_eager=bool(not current_platform.is_tpu()),
max_model_len=1024,
max_num_seqs=16,
guided_decoding_backend=guided_decoding_backend,
guided_decoding_disable_any_whitespace=True,
tokenizer_mode=tokenizer_mode,
reasoning_parser=reasoning_parser,
speculative_config=speculative_config,
)
tokenizer = llm.get_tokenizer(None)
reasoner = ReasoningParserManager.get_reasoning_parser(reasoning_parser)(
tokenizer=tokenizer)
reasoning_prompt = "Solve the following math problem step-by-step, then provide the final answer as JSON object with a single key 'result'. Make sure to correct your reasoning if there are any issue should it arise.\nProblem: What is 5 * 8 + 2?" # noqa: E501
reasoning_schema = {
"type": "object",
"properties": {
"result": {
"type": "integer"
}
},
"required": ["result"],
"additionalProperties": False
}
if "Qwen3" in model_name:
reasoning_prompt += "\n"
sampling_params = SamplingParams(
temperature=0.1,
max_tokens=8192,
guided_decoding=GuidedDecodingParams(json=reasoning_schema),
)
outputs = llm.generate(
[reasoning_prompt],
sampling_params=sampling_params,
use_tqdm=True,
)
assert outputs is not None
output = outputs[0]
assert output is not None and isinstance(output, RequestOutput)
prompt = output.prompt
generated_text = output.outputs[0].text
reasoning_content, content = run_reasoning_extraction(
reasoner, [generated_text])
print(
f"Prompt: {prompt!r}\nReasoning: {reasoning_content!r}\nContent: {content!r}"
)
assert content is not None and reasoning_content is not None
output_json = json.loads(content)
jsonschema.validate(instance=output_json, schema=reasoning_schema)
@pytest.mark.skip_global_cleanup
@pytest.mark.parametrize("model_name, tokenizer_mode",
PARAMS_MODELS_TOKENIZER_MODE)
def test_structured_output_auto_mode(
monkeypatch: pytest.MonkeyPatch,
unsupported_json_schema: dict[str, Any],
model_name: str,
tokenizer_mode: str,
):
monkeypatch.setenv("VLLM_USE_V1", "1")
llm = LLM(model=model_name,
max_model_len=1024,
guided_decoding_backend="auto",
tokenizer_mode=tokenizer_mode)
sampling_params = SamplingParams(
temperature=1.0,
max_tokens=1000,
guided_decoding=GuidedDecodingParams(json=unsupported_json_schema))
prompts = (
"Give an example JSON object for a grade "
"that fits this schema: "
f"{unsupported_json_schema}. Make the response as short as possible.")
# This would fail with the default of "xgrammar", but in "auto"
# we will handle fallback automatically.
outputs = llm.generate(prompts=prompts,
sampling_params=sampling_params,
use_tqdm=True)
# Make sure `auto` backend handling doesn't mess up sampling_params
# and that we can reuse it without error.
outputs.extend(
llm.generate(prompts=prompts,
sampling_params=sampling_params,
use_tqdm=True))
assert outputs is not None
for output in outputs:
assert output is not None
assert isinstance(output, RequestOutput)
generated_text = output.outputs[0].text
assert generated_text is not None
print(generated_text)
# Parse to verify it is valid JSON
parsed_json = json.loads(generated_text)
assert isinstance(parsed_json, dict)
@pytest.mark.skip_global_cleanup
def test_guidance_no_additional_properties(monkeypatch: pytest.MonkeyPatch):
monkeypatch.setenv("VLLM_USE_V1", "1")
llm = LLM(model="Qwen/Qwen2.5-1.5B-Instruct",
max_model_len=1024,
guided_decoding_backend="guidance",
guided_decoding_disable_any_whitespace=True,
guided_decoding_disable_additional_properties=True)
schema = {
'type': 'object',
'properties': {
'a1': {
'type': 'string'
},
'a2': {
'type': 'string'
},
'a3': {
'type': 'string'
}
},
'required': ['a1', 'a2', 'a3'],
}
prompt = (
"<|im_start|>system\nYou are Qwen, created by Alibaba Cloud. You are a "
"helpful assistant.<|im_end|>\n<|im_start|>user\nPlease generate a "
"large JSON object with key-value pairs a1=b1, a2=b2, ..., a20=b20. "
"Make the response as short as possible."
"<|im_end|>\n<|im_start|>assistant\n")
def generate_with_backend(backend):
guided_params = GuidedDecodingParams(
json=schema,
backend=backend,
disable_any_whitespace=True,
disable_additional_properties=True)
sampling_params = SamplingParams(temperature=0,
max_tokens=256,
guided_decoding=guided_params)
outputs = llm.generate(prompts=prompt, sampling_params=sampling_params)
assert outputs is not None
generated_text = outputs[0].outputs[0].text
assert generated_text is not None
parsed_json = json.loads(generated_text)
assert isinstance(parsed_json, dict)
jsonschema.validate(instance=parsed_json, schema=schema)
return parsed_json
generated = generate_with_backend("guidance")
assert "a1" in generated
assert "a2" in generated
assert "a3" in generated
assert "a4" not in generated
assert "a5" not in generated
assert "a6" not in generated