[Fix] Resolve VLM test image placeholders from the model's own chat template (#33509)

This commit is contained in:
Liangsheng Yin
2026-08-04 02:01:39 -07:00
committed by GitHub
parent 26a542722f
commit b6d548afd7
7 changed files with 110 additions and 48 deletions
+16
View File
@@ -183,6 +183,22 @@ def download_image_with_retry(image_url: str, max_retries: int = 3) -> Image.Ima
time.sleep(2**i)
def build_vlm_image_prompt(processor, question: str) -> str:
# Take the image placeholder from the model's own HF chat template: a
# hand-written one silently degrades to a text-only prompt on any model
# whose placeholder differs.
return processor.apply_chat_template(
[
{
"role": "user",
"content": [{"type": "image"}, {"type": "text", "text": question}],
}
],
tokenize=False,
add_generation_prompt=True,
)
def is_in_ci():
"""Return whether it is in CI runner."""
return get_bool_env_var("SGLANG_IS_IN_CI")
@@ -3,7 +3,6 @@ from types import SimpleNamespace
import requests
from sglang.lang.chat_template import get_chat_template_by_model_path
from sglang.srt.utils import kill_process_tree
from sglang.test.kits.ebnf_constrained_kit import EBNFConstrainedMixin
from sglang.test.kits.json_constrained_kit import JSONConstrainedMixin
@@ -164,24 +163,38 @@ class TestDPAttentionDP2TP4VLM(CustomTestCase):
kill_process_tree(cls.process.pid)
def test_vlm_generate(self):
chat_template = get_chat_template_by_model_path(self.model)
prompt = f"{chat_template.image_token}What is in this image?"
# Go through /v1/chat/completions so the server inserts the model's own
# image placeholder instead of the test guessing one.
response = requests.post(
self.base_url + "/generate",
self.base_url + "/v1/chat/completions",
json={
"text": prompt,
"image_data": [self.image_url],
"sampling_params": {
"temperature": 0,
"max_new_tokens": 16,
},
"model": "default",
"messages": [
{
"role": "user",
"content": [
{
"type": "image_url",
"image_url": {"url": self.image_url},
},
{"type": "text", "text": "What is in this image?"},
],
}
],
"temperature": 0,
"max_tokens": 16,
},
)
response.raise_for_status()
response_json = response.json()
print(response_json)
self.assertIn("output_ids", response_json)
self.assertGreater(len(response_json["output_ids"]), 0)
self.assertTrue(response_json["choices"][0]["message"]["content"])
# image_tokens comes from the prefill's multimodal item offsets, so a
# non-zero count is what proves the image reached the vision tower.
usage_details = response_json["usage"].get("prompt_tokens_details")
self.assertIsNotNone(usage_details, "prompt carried no multimodal tokens")
self.assertGreater(usage_details.get("image_tokens", 0), 0)
if __name__ == "__main__":
+5 -3
View File
@@ -1,9 +1,9 @@
import unittest
import requests
from transformers import AutoProcessor
from sglang import Engine
from sglang.lang.chat_template import get_chat_template_by_model_path
from sglang.srt.utils import kill_process_tree
from sglang.test.kits.eval_accuracy_kit import MMLUMixin
from sglang.test.test_utils import (
@@ -13,6 +13,7 @@ from sglang.test.test_utils import (
DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
DEFAULT_URL_FOR_TEST,
CustomTestCase,
build_vlm_image_prompt,
is_in_amd_ci,
popen_launch_server,
)
@@ -72,8 +73,9 @@ class TestTorchAO(CustomTestCase, MMLUMixin):
class TestTorchAOForVLM(CustomTestCase):
def test_vlm_generate(self):
model_path = DEFAULT_SMALL_VLM_MODEL_NAME_FOR_TEST
chat_template = get_chat_template_by_model_path(model_path)
text = f"{chat_template.image_token}What is in this picture? Answer: "
text = build_vlm_image_prompt(
AutoProcessor.from_pretrained(model_path), "What is in this picture?"
)
engine = Engine(
model_path=model_path,
@@ -1,9 +1,9 @@
import unittest
import torch
from transformers import AutoProcessor
from sglang import Engine
from sglang.lang.chat_template import get_chat_template_by_model_path
from sglang.srt.utils import kill_process_tree
from sglang.test.ci.ci_register import register_amd_ci, register_cuda_ci
from sglang.test.run_eval import run_eval
@@ -13,6 +13,7 @@ from sglang.test.test_utils import (
DEFAULT_URL_FOR_TEST,
CustomTestCase,
SimpleNamespace,
build_vlm_image_prompt,
is_in_amd_ci,
popen_launch_server,
)
@@ -73,8 +74,9 @@ class TestPiecewiseCudaGraphQwen25VLEmbedding(CustomTestCase):
def test_embedding(self):
model_path = "Qwen/Qwen2.5-VL-3B-Instruct"
chat_template = get_chat_template_by_model_path(model_path)
text = f"{chat_template.image_token}What is in this picture? Answer: "
text = build_vlm_image_prompt(
AutoProcessor.from_pretrained(model_path), "What is in this picture?"
)
extra_args = (
{"mem_fraction_static": AMD_MEM_FRACTION_STATIC} if is_in_amd_ci() else {}
)
+25 -12
View File
@@ -2,7 +2,6 @@ import unittest
import requests
from sglang.lang.chat_template import get_chat_template_by_model_path
from sglang.srt.environ import envs
from sglang.srt.utils import kill_process_tree
from sglang.test.ci.ci_register import register_amd_ci, register_cuda_ci
@@ -204,24 +203,38 @@ class TestDPAttentionDP2TP2VLM(CustomTestCase):
kill_process_tree(cls.process.pid)
def test_vlm_generate(self):
chat_template = get_chat_template_by_model_path(self.model)
prompt = f"{chat_template.image_token}What is in this image?"
# Go through /v1/chat/completions so the server inserts the model's own
# image placeholder instead of the test guessing one.
response = requests.post(
self.base_url + "/generate",
self.base_url + "/v1/chat/completions",
json={
"text": prompt,
"image_data": [self.image_url],
"sampling_params": {
"temperature": 0,
"max_new_tokens": 16,
},
"model": "default",
"messages": [
{
"role": "user",
"content": [
{
"type": "image_url",
"image_url": {"url": self.image_url},
},
{"type": "text", "text": "What is in this image?"},
],
}
],
"temperature": 0,
"max_tokens": 16,
},
)
response.raise_for_status()
response_json = response.json()
print(response_json)
self.assertIn("output_ids", response_json)
self.assertGreater(len(response_json["output_ids"]), 0)
self.assertTrue(response_json["choices"][0]["message"]["content"])
# image_tokens comes from the prefill's multimodal item offsets, so a
# non-zero count is what proves the image reached the vision tower.
usage_details = response_json["usage"].get("prompt_tokens_details")
self.assertIsNotNone(usage_details, "prompt carried no multimodal tokens")
self.assertGreater(usage_details.get("image_tokens", 0), 0)
if __name__ == "__main__":
@@ -2,7 +2,6 @@ import unittest
import requests
from sglang.lang.chat_template import get_chat_template_by_model_path
from sglang.srt.environ import envs
from sglang.srt.utils import kill_process_tree
from sglang.test.ascend.npu_eval_accuracy_kit import NPUGSM8KMixin
@@ -175,24 +174,38 @@ class TestDPAttentionDP2TP2VLM(CustomTestCase):
kill_process_tree(cls.process.pid)
def test_vlm_generate(self):
chat_template = get_chat_template_by_model_path(self.model)
prompt = f"{chat_template.image_token}What is in this image?"
# Go through /v1/chat/completions so the server inserts the model's own
# image placeholder instead of the test guessing one.
response = requests.post(
self.base_url + "/generate",
self.base_url + "/v1/chat/completions",
json={
"text": prompt,
"image_data": [self.image_url],
"sampling_params": {
"temperature": 0,
"max_new_tokens": 16,
},
"model": "default",
"messages": [
{
"role": "user",
"content": [
{
"type": "image_url",
"image_url": {"url": self.image_url},
},
{"type": "text", "text": "What is in this image?"},
],
}
],
"temperature": 0,
"max_tokens": 16,
},
)
response.raise_for_status()
response_json = response.json()
print(response_json)
self.assertIn("output_ids", response_json)
self.assertGreater(len(response_json["output_ids"]), 0)
self.assertTrue(response_json["choices"][0]["message"]["content"])
# image_tokens comes from the prefill's multimodal item offsets, so a
# non-zero count is what proves the image reached the vision tower.
usage_details = response_json["usage"].get("prompt_tokens_details")
self.assertIsNotNone(usage_details, "prompt carried no multimodal tokens")
self.assertGreater(usage_details.get("image_tokens", 0), 0)
if __name__ == "__main__":
@@ -9,7 +9,6 @@ import unittest
import requests
from transformers import AutoProcessor, AutoTokenizer
from sglang.lang.chat_template import get_chat_template_by_model_path
from sglang.srt.utils import kill_process_tree
from sglang.test.ci.ci_register import register_amd_ci, register_cuda_ci
from sglang.test.test_utils import (
@@ -19,6 +18,7 @@ from sglang.test.test_utils import (
DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
DEFAULT_URL_FOR_TEST,
CustomTestCase,
build_vlm_image_prompt,
download_image_with_retry,
popen_launch_server,
)
@@ -91,9 +91,13 @@ class TestSkipTokenizerInit(CustomTestCase):
self.assertEqual(item["meta_info"]["prompt_tokens"], len(input_ids))
if return_logprob:
num_input_logprobs = len(input_ids) - request["logprob_start_len"]
if num_input_logprobs > len(input_ids):
num_input_logprobs -= len(input_ids)
# -1 resolves to the prompt end, so no input logprob is returned.
if request["logprob_start_len"] == -1:
num_input_logprobs = 0
else:
num_input_logprobs = (
len(input_ids) - request["logprob_start_len"]
)
self.assertEqual(
len(item["meta_info"]["input_token_logprobs"]),
num_input_logprobs,
@@ -230,8 +234,7 @@ class TestSkipTokenizerInitVLM(TestSkipTokenizerInit):
cls.eos_token_id = [cls.tokenizer.eos_token_id]
def get_input_ids(self, _prompt_text) -> list[int]:
chat_template = get_chat_template_by_model_path(self.model)
text = f"{chat_template.image_token}What is in this picture?"
text = build_vlm_image_prompt(self.processor, "What is in this picture?")
inputs = self.processor(
text=[text],
images=[self.image],