From 0849c5efd87404b6e27f4df2c43d2b7baab83990 Mon Sep 17 00:00:00 2001
From: Lingfeng Zhang <48312954+lcukyfuture@users.noreply.github.com>
Date: Wed, 25 Mar 2026 14:21:04 +0800
Subject: [PATCH] [Test] Add L4 diffusion feature test for LongCat-Image
 (#1970)

Signed-off-by: lcukyfuture <zlf994478451@outlook.com>
Signed-off-by: Lingfeng Zhang <48312954+lcukyfuture@users.noreply.github.com>
---
 .../test_longcat_image_expansion.py           | 83 +++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 tests/e2e/online_serving/test_longcat_image_expansion.py

diff --git a/tests/e2e/online_serving/test_longcat_image_expansion.py b/tests/e2e/online_serving/test_longcat_image_expansion.py
new file mode 100644
index 000000000..161e7cd2e
--- /dev/null
+++ b/tests/e2e/online_serving/test_longcat_image_expansion.py
@@ -0,0 +1,83 @@
+"""
+Recommended tests of diffusion features that are available in online serving mode
+and are supported by the following model:
+- LongCat-Image: text-to-image with single prompt input
+Coverage:
+- CPU offloading (model-level sequential offload via --enable-cpu-offload)
+- Cache-DiT
+- SP (Ulysses)
+
+This validates:
+ - Successful image generation at the expected 768x1344 resolution with recommended feature combinations
+"""
+
+import pytest
+
+from tests.conftest import (
+    OmniServer,
+    OmniServerParams,
+    OpenAIClientHandler,
+    dummy_messages_from_mix_data,
+)
+from tests.utils import hardware_marks
+
+TEXT_TO_IMAGE_PROMPT = (
+    "A cinematic illustration of a cat typing on a silver laptop, soft window light, highly detailed."
+)
+NEGATIVE_PROMPT = "blurry, low quality, distorted, oversaturated"
+SINGLE_CARD_FEATURE_MARKS = hardware_marks(res={"cuda": "H100"})
+PARALLEL_FEATURE_MARKS = hardware_marks(res={"cuda": "H100"}, num_cards=2)
+
+
+def _get_diffusion_feature_cases(model: str):
+    """Return diffusion feature cases for LongCat-Image."""
+    return [
+        pytest.param(
+            OmniServerParams(
+                model=model,
+                server_args=["--enable-cpu-offload"],
+            ),
+            id="single_card_001",
+            marks=SINGLE_CARD_FEATURE_MARKS,
+        ),
+        pytest.param(
+            OmniServerParams(
+                model=model,
+                server_args=[
+                    "--cache-backend",
+                    "cache_dit",
+                    "--ulysses-degree",
+                    "2",
+                ],
+            ),
+            id="parallel_001",
+            marks=PARALLEL_FEATURE_MARKS,
+        ),
+    ]
+
+
+@pytest.mark.advanced_model
+@pytest.mark.diffusion
+@pytest.mark.parametrize(
+    "omni_server",
+    _get_diffusion_feature_cases("meituan-longcat/LongCat-Image"),
+    indirect=True,
+)
+def test_longcat_image(omni_server: OmniServer, openai_client: OpenAIClientHandler):
+    """Test the recommended feature combinations for LongCat-Image."""
+    messages = dummy_messages_from_mix_data(content_text=TEXT_TO_IMAGE_PROMPT)
+
+    request_config = {
+        "model": omni_server.model,
+        "messages": messages,
+        "extra_body": {
+            "height": 768,
+            "width": 1344,
+            "num_inference_steps": 2,
+            "negative_prompt": NEGATIVE_PROMPT,
+            "guidance_scale": 4.0,
+            "seed": 42,
+        },
+    }
+
+    openai_client.send_diffusion_request(request_config)