vllm-omni/docs/contributing/ci/test_writing_guide.md

# Test Writing Guide

This document describes how to author tests for each CI level (L1–L5). For the level matrix, CI triggers, and Buildkite upload behavior, see [Test System Overview](./test_system_overview.md).

## Test Directory Structure

Canonical placement by CI level is in the **Test Dir** column of the level matrix in [Test System Overview](./test_system_overview.md).

Summary:

- **Component / unit:** `tests/{component}/…` mirroring `vllm_omni/{component}/`
- **Model E2E:** `tests/e2e/online_serving/`, `tests/e2e/offline_inference/`, `tests/e2e/accuracy/`
- **Feature integration:** `tests/e2e/features/<feature>/`
- **Doc example tests:** `tests/examples/online_serving/`, `tests/examples/offline_inference/`
- **Performance:** `tests/dfx/perf/tests/` (JSON configs; runners under `tests/dfx/perf/scripts/`)
- **Stability:** `tests/dfx/stability/tests/`
- **Reliability:** `tests/dfx/reliability/`
- Do **not** add new top-level `tests/` directories unrelated to a component (or to `e2e` / `dfx` / `helpers` / `examples` / `buildkite`)

Deploy YAMLs: `vllm_omni/deploy/` via `tests.helpers.stage_config.get_deploy_config_path` (see [stage configs](../../configuration/stage_configs.md)).

## Markers for Tests

By adding markers before test functions, tests can later be executed uniformly by simply declaring the corresponding marker type.

### Current Markers
Defined in `pyproject.toml`:

| Marker             | Description                                               |
| ------------------ | --------------------------------------------------------- |
| `core_model`       | L1&L2 tests (run in each PR)                              |
| `advanced_model`   | L3 tests (run on each merge to main)                 |
| `full_model`       | L4 tests (run nightly) |
| `diffusion`        | Diffusion model tests                                     |
| `omni`             | Omni multimodal model tests |
| `tts`              | TTS model tests     |
| `cache`            | Cache backend tests                                       |
| `parallel`         | Parallelism/distributed tests                             |
| `cpu`              | Tests that run on CPU                                     |
| `gpu`              | Tests that run on GPU *                                   |
| `cuda`             | Tests that run on CUDA *                                  |
| `rocm`             | Tests that run on AMD/ROCm *                              |
| `xpu`              | Tests that run on Intel XPU *                             |
| `npu`              | Tests that run on NPU/Ascend *                            |
| `H100`             | Tests that require H100 GPU  *                            |
| `L4`               | Tests that require L4 GPU *                               |
| `MI325`            | Tests that require MI325 GPU (AMD/ROCm) *                 |
| `A2`               | Tests that require A2 NPU *                               |
| `A3`               | Tests that require A3 NPU *                               |
| `distributed_cuda` | Tests that require multi cards on CUDA platform *         |
| `distributed_rocm` | Tests that require multi cards on ROCm platform  *        |
| `distributed_npu`  | Tests that require multi cards on NPU platform  *         |
| `skipif_cuda`      | Skip if the num of CUDA cards is less than the required * |
| `skipif_rocm`      | Skip if the num of ROCm cards is less than the required * |
| `skipif_npu`       | Skip if the num of NPU cards is less than the required *  |
| `slow`             | Slow tests (may skip in quick CI)                         |
| `benchmark`        | Benchmark tests (decorator on runner test functions; perf JSON uses `full_model` + type marker instead) |
| `local_model`      | Tests requiring local / non-HF-hub model weights          |

\* Means those markers are auto-added by `@hardware_test` (parametrization decorator) or `hardware_marks` (only returning the list of marks for flexibility).

#### Example usage for markers

```python
from tests.helpers.mark import hardware_test

@pytest.mark.core_model
@pytest.mark.omni
@hardware_test(
   res={"cuda": "L4", "rocm": "MI325", "npu": "A2"},
   num_cards=2,
)
@pytest.mark.parametrize("omni_server", test_params, indirect=True)
def test_video_to_audio()
    ...
```

#### Decorator: `@hardware_test`

This decorator is intended to make hardware-aware, cross-platform test authoring easier and more robust for CI/CD environments. The `hardware_test` decorator in `vllm-omni/tests/helpers/mark.py` performs the following actions:

1. **Applies platform and resource markers**  
   Adds the appropriate pytest markers for each specified hardware platform (e.g., `cuda`, `rocm`, `xpu`, `npu`) and resource type (e.g., `L4`, `H100`, `MI325`, `B60`, `A2`, `A3`).
   ```
   @pytest.mark.cuda
   @pytest.mark.L4
   ```
2. **Handles multi-card (distributed) scenarios**  
   For tests requiring multiple cards, it automatically adds distributed markers such as `distributed_cuda`, `distributed_rocm`, or `distributed_npu`.
   ```
   @pytest.mark.distributed_cuda(num_cards=num_cards)
   ```
3. **Supports flexible card requirements**  
   Accepts `num_cards` as either a single integer for all platforms or as a dictionary with per-platform values. If not specified, defaults to 1 card per platform.

4. **Integrates resource validation**  
   On CUDA, adds a skip marker (`skipif_cuda`) if the system does not have the required number of devices.
   Support for `skipif_rocm` and `skipif_npu` will be implemented later.


5. **Works with pytest filtering**  
   Allows tests to be filtered and selected at runtime using standard pytest marker expressions (e.g., `-m "distributed_cuda and L4"`).

##### Example usage for decorator
- Single call for multiple platforms:
    ```python
    @hardware_test(
        res={"cuda": "L4", "rocm": "MI325", "xpu": "B60", "npu": "A2"},
        num_cards={"cuda": 2, "rocm": 2, "xpu": 2, "npu": 2},
    )
    ```
    or
    ```python
    @hardware_test(
        res={"cuda": "L4", "rocm": "MI325", "xpu": "B60", "npu": "A2"},
        num_cards=2,
    )
    ```
- `res` must be a dict; supported resources: CUDA (L4/H100), ROCm (MI325), XPU (B60), MUSA (S5000), NPU (A2/A3)
- `num_cards` can be int (all platforms) or dict (per platform); defaults to 1 when missing
- Distributed markers (`distributed_cuda`, `distributed_rocm`, `distributed_npu`) are auto-added for multi-card cases
- Filtering examples:
    - CUDA only: `pytest -m "distributed_cuda and L4"`
    - ROCm only: `pytest -m "distributed_rocm and MI325"`
    - NPU only: `pytest -m "distributed_npu"`

#### Function: `hardware_marks`

`hardware_marks` returns a list of pytest mark objects with the same signature as `@hardware_test`. Use it when you need more flexibility, such as attaching hardware marks to individual `pytest.param` entries rather than an entire test function.

```python
from tests.helpers.mark import hardware_marks

MULTI_CARD_MARKS = hardware_marks(
    res={"cuda": "H100", "rocm": "MI325", "npu": "A2"}, num_cards=2
)

@pytest.mark.parametrize("omni_server", [
    pytest.param(OmniServerParams(...), id="case_001", marks=MULTI_CARD_MARKS),
], indirect=True)
def test_feature(omni_server):
    ...
```

#### JSON `mark` field (L4 perf configs)

Perf JSON under `tests/dfx/perf/tests/` can attach pytest marks per **case** (`test_name` block). Parsed by `tests.dfx.conftest.resolve_pytest_marks` and applied to each parametrized run in `run_benchmark.py` / `run_diffusion_benchmark.py`.

When `mark` is present, it must be an **array** with exactly one ``hardware_marks`` object (same semantics as `hardware_marks()` above), followed by registered pytest marker name strings such as `full_model`, `omni`, `tts`, or `diffusion`.

```json
{
  "test_name": "test_cosmos3_t2i_official_demo_2gpu",
  "mark": [
    {"hardware_marks": {"res": {"cuda": "H100"}, "num_cards": 2}},
    "full_model",
    "diffusion"
  ],
  "server_type": "vllm-omni",
  "server_params": { "...": "..." },
  "benchmark_params": [{ "name": "1024x1024_steps4", "...": "..." }]
}
```

- Local bulk load: `pytest -sv tests/dfx/perf/scripts/run_diffusion_benchmark.py -m "full_model and diffusion and H100"`
- Nightly CI perf steps: `--test-config-file tests/dfx/perf/tests/test_<model>_vllm_omni.json` (file selects cases; no `-m`)
- Result filenames use **runtime** GPU detection (`get_runtime_resource_label`); `H100` is omitted on the default CI pool

See [L4 performance test examples](./test_examples/l4_performance_tests.inc.md) for the full schema.

### Add Support for a New Platform

If you want to add support for a new platform (e.g., "tpu" for a new accelerator), follow these steps:

1. **Extend the marker list in your pytest config** so that platform/resource markers are defined:
   ```toml
   # In pyproject.toml or pytest.ini
   [tool.pytest.ini_options]
   markers = [
       # ... existing markers ...
       "tpu: Tests that require TPU device",
       "TPU_V3: Tests that require TPU v3 hardware",
       "distributed_tpu: Tests that require multiple TPU devices",
   ]
   ```
2. **Implement a marker construction function for your platform** in `vllm-omni/tests/helpers/mark.py`:
   ```python
   # In vllm-omni/tests/helpers/mark.py

   def tpu_marks(*, res: str, num_cards: int):
       test_platform = pytest.mark.tpu
       if res == "TPU_V3":
           test_resource = pytest.mark.TPU_V3
       else:
           raise ValueError(
               f"Invalid TPU resource type: {res}. Supported: TPU_V3")

       if num_cards == 1:
           return [test_platform, test_resource]
       else:
           test_distributed = pytest.mark.distributed_tpu(num_cards=num_cards)
           # Optionally: add skipif_tpu when implemented
           return [test_platform, test_resource, test_distributed]
   ```
3. **Update `hardware_marks` to recognize your new platform**:
    In the relevant place (see the `hardware_marks` implementation), add:
    ```python
    if platform == "tpu":
        marks = tpu_marks(res=resource, num_cards=cards)
    ```
    (`hardware_test` calls `hardware_marks` internally, so both will pick up the change.)
4. **(Recommended) Add a test using your new markers**:
   ```python
   @hardware_test(
       res={"tpu": "TPU_V3"},
       num_cards=2,
   )
   def test_my_tpu_feature():
       ...
   ```

**Summary**:  
- Add pytest markers for your new platform/resources  
- Implement a marker function (`xxx_marks`)  
- Plug into `hardware_marks`  
- You're done: tests using `@hardware_test` or `hardware_marks` with your platform now automatically get the correct markers, distribution, and isolation!

See code in `vllm-omni/tests/helpers/mark.py` for existing examples (`cuda_marks`, `rocm_marks`, `npu_marks`).

## Test case style

### L1 & L2 Level Testing - Unit Testing and Basic End-to-End Verification

#### 1.1 Testing Purpose

L1 and L2 level testing form the foundation of the quality assurance system. L1 level testing focuses on verifying the internal logic correctness of code units (e.g., functions, classes), ensuring each independent component behaves as designed.

L2 level testing builds upon L1 by introducing GPU resources and verifying that the end-to-end (E2E) process of the model in basic deployment scenarios is smooth. For example, it uses dummy models to confirm that core interfaces like the inference pipeline, output format, and streaming response work properly. The common goal of these two levels is to provide developers with rapid feedback, discovering and fixing issues early in the development cycle.



#### 1.2 Testing Content and Scope

-   ***L1 (Unit & Logic Testing)***:
-   -   ***Scope***: Tests internal functions and methods of core components such as `entrypoints`, `models`.
    -   ***Focus***: Branch coverage, exception handling, algorithm logic correctness. Does not involve external dependencies or the complete service stack.
    -   ***Time Cost***: Execution time is controlled within ***15 minutes*** to ensure fast feedback.
-   ***L2 (Basic End-to-End Testing)***:
-   -   ***Scope***: Covers two basic deployment scenarios: `online` (serving) and `offline` (inference).
    -   ***Focus***: Uses `dummy` weights (via deploy YAML patching at `core_model`) or lightweight real models to verify that the entire chain from request input to result output works normally, including output data structure, streaming (stream) support, and **cheap payload checks** at `--run-level core_model` (see below). Also includes some unit tests that require launching independent service instances.
    -   ***L2 response validation (`core_model`)***: Implemented in `tests/helpers/assertions.py` and invoked by `OpenAIClientHandler` based on `--run-level`. At L2 we require **request success** plus minimal output sanity—not full accuracy:
        -   **Speech / TTS** (`assert_audio_speech_response`): decoded audio must be present and non-empty (or exceed `min_audio_bytes` when set in `request_config`); `response_format` must match the returned content-type (e.g. `wav`, `pcm`). Whisper transcript similarity, PCM HNR, and preset-voice gender checks run only at L3+.
        -   **Diffusion** (`assert_diffusion_response`): at least one non-empty image, video, or audio artifact. Resolution/frame-count parity and other deep checks run only at L3+.
        -   **Omni multimodal** (`assert_omni_response`): L2 asserts successful completion; keyword, transcript, and cross-modal similarity checks run only at L3+.
    -   ***Characteristic***: Requires ***GPU*** resources to perform model computations.

#### 1.3 Test Directory and Execution Files

A clear directory structure is key to managing test cases efficiently. See the **Test Dir** column in [Test System Overview](./test_system_overview.md) for the canonical placement rules.

-   ***L1 (component / unit)***: `tests/{component_name}/…` mirroring `vllm_omni/{component_name}/` (e.g. `tests/diffusion/`, `tests/entrypoints/`). Do **not** invent new top-level `tests/` folders unrelated to a component.
-   ***L2 (basic model E2E)***:
    -   Online serving: `tests/e2e/online_serving/test_{model_name}.py`
    -   Offline inference: `tests/e2e/offline_inference/test_{model_name}.py`
-   ***Feature-level integration*** (cross-cutting, not a single-model smoke): `tests/e2e/features/<feature>/` (e.g. `fullduplex/`, `custom_pipeline/`, `rlhf_test/`).

#### 1.4 Execution Method and Example

-   ***Trigger Timing***: **`PR with ready label`**. That is, when a developer adds a "ready for review" or similar label to a PR on platforms like GitHub, L1 and L2 tests are automatically triggered.
-   ***Diff-aware step skipping***: On L2, **E2E Test** jobs may be omitted at pipeline upload when the PR diff does not touch their [`source_file_dependencies`](ci_settings.md#step-filtering) prefixes; non-E2E groups still always upload. See [CI Settings — Diff-aware CI](ci_settings.md#diff-aware-ci).
-   ***Execution Environment***: L1 uses ***CPU*** environment; L2 requires ***GPU*** environment.
-   ***Script Example***:

<details>
<summary> L1 Test Examples</summary>

Examples from `tests/model_executor/models/qwen2_5_omni/test_audio_length.py`
```python
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project

import pytest

pytestmark = [pytest.mark.core_model, pytest.mark.cpu]

def test_resolve_max_mel_frames_default():
    from vllm_omni.model_executor.models.qwen2_5_omni.audio_length import resolve_max_mel_frames

    assert resolve_max_mel_frames(None, default=30000) == 30000
    assert resolve_max_mel_frames(None, default=6000) == 6000


def test_resolve_max_mel_frames_explicit():
    from vllm_omni.model_executor.models.qwen2_5_omni.audio_length import resolve_max_mel_frames

    # Explicit argument always wins over default
    assert resolve_max_mel_frames(123, default=30000) == 123
    assert resolve_max_mel_frames(6000, default=30000) == 6000
    assert resolve_max_mel_frames(0, default=30000) == 0


@pytest.mark.parametrize("repeats", [2, 4])
@pytest.mark.parametrize("code_len", [0, 1, 32768])
@pytest.mark.parametrize("max_mel_frames", [None, -1, 0, 1, 6000, 30000])
def test_cap_and_align_mel_length_no_mismatch(repeats, code_len, max_mel_frames):
    """Guard that any max_mel_frames yields a mel length aligned to repeats, and
    consistent with the truncated code length (prevents concat mismatch).
    """
    from vllm_omni.model_executor.models.qwen2_5_omni.audio_length import cap_and_align_mel_length

    target_code_len, target_mel_len = cap_and_align_mel_length(
        code_len=code_len,
        repeats=repeats,
        max_mel_frames=max_mel_frames,
    )

    assert isinstance(target_code_len, int)
    assert isinstance(target_mel_len, int)

    if code_len == 0:
        assert target_code_len == 0
        assert target_mel_len == 0
        return

    assert target_code_len >= 1
    assert target_mel_len >= repeats
    assert target_mel_len % repeats == 0
    assert target_mel_len == target_code_len * repeats
    assert target_code_len <= code_len

    if max_mel_frames is not None and int(max_mel_frames) > 0 and int(max_mel_frames) >= repeats:
        assert target_mel_len <= int(max_mel_frames)
```
</details>

<details>
<summary> L2 Test Examples</summary>
You can refer to Test Examples in the L3 section to see example test cases that incorporate both L2 and L3 testing logic.
</details>

-   -   ***Run Command***:

    `pytest -s -v /tests/e2e/online_serving/test_{model_name}.py`
    `pytest -s -v -m 'core_model and cpu' --run-level=core_model`

### L3 Level Testing - Core Integration, Performance, and Accuracy Verification

#### 2.1 Testing Purpose

L3 level testing executes after code is merged into the main branch. Its core purpose is to verify the integration effect, key performance indicators, and output accuracy of ***real models*** in ***multiple deployment scenarios***

. It acts as the "quality gatekeeper" for the main branch, ensuring that no merge breaks the core capabilities of the model service. Testing needs to provide clear conclusions within a relatively short time (<30min), balancing test depth with feedback speed.



#### 2.2 Testing Content and Scope

-   ***Deployment Scenarios***: Covers richer `online` and `offline` deployment configurations, which may include different hardware configurations, batch sizes, concurrency levels, etc.
-   ***Core Verification***:
-   1.  ***Inference Functionality***: Ensures real models can perform forward computation normally and return results.
    2.  ***Accuracy Compliance***: Verifies that the model's evaluation metrics (e.g., accuracy) meet the expected baseline, preventing code changes from introducing accuracy issues.
    3.  ***Important Performance***: Verifies whether performance (e.g., P99 latency, throughput) in core scenarios meets preset thresholds.
-   ***L3 response validation (`advanced_model`)***: At `--run-level advanced_model`, `tests/helpers/assertions.py` adds semantic checks on top of L2 payload gates (see L1 & L2 above):
    -   **Speech / TTS** (`assert_audio_speech_response`): Whisper transcript of returned audio vs `request_config["input"]` (cosine similarity &gt; 0.9 when input text is set); optional `min_audio_bytes` floor; PCM harmonic-to-noise ratio when `response_format` is `pcm`; **preset voice gender** via `_assert_preset_voice_gender_from_audio` when `voice` matches a known preset in `_PRESET_VOICE_GENDER_MAP` (pitch/F0-based classifier; skipped for unknown voices or `pcm` output).
    -   **Omni multimodal** (`assert_omni_response`): non-empty text/audio outputs; `key_words` in transcript or text; text–audio similarity / containment; preset **`speaker`** gender check (same helper as TTS).
    -   **Diffusion** (`assert_*_diffusion_response`): image/video dimension and frame-count parity with request parameters where configured.
    -   **Accuracy suites**: pixel/video similarity and metric baselines under `/tests/e2e/accuracy/` (separate from inline helper assertions).

#### 2.3 Test Directory and Execution Files

-   ***Functional / model E2E***:
    -   Online serving: `tests/e2e/online_serving/test_{model_name}_expansion.py`
    -   Offline inference: `tests/e2e/offline_inference/test_{model_name}_expansion.py`
    -   Accuracy / similarity: `tests/e2e/accuracy/`
    -   (`_expansion.py` holds broader scenario coverage than the L2 smoke file.)
-   ***Feature-level integration***: `tests/e2e/features/<feature>/` (not under a new top-level `tests/` directory).

#### 2.4 Execution Method and Example

-   ***Trigger Timing***: **`PR Merged`**. Automatically triggered after code review is approved and merged into the main branch (typically via `merge-test` label on the PR before merge).
-   ***Diff-aware step skipping***: Same [`source_file_dependencies`](ci_settings.md#step-filtering) mechanism as L2—**all E2E Test** leaf steps are diff-gated; other L3 groups always upload. See [CI Settings — Diff-aware CI](ci_settings.md#diff-aware-ci).
-   ***Execution Environment***: ***GPU*** servers.
-   ***Script Example***:

???+ example "Test Examples"

    **2.4.1 Mark Declaration Section**

    ```python
    @pytest.mark.advanced_model
    @pytest.mark.core_model
    @pytest.mark.parametrize("omni_server", test_params, indirect=True)
    ```

    **Explanation**:

    @pytest.mark.advanced_model: Marks the test as L3 merge level (`--run-level advanced_model`): real weights, Whisper/similarity/keyword checks, diffusion deep checks, and **preset voice/speaker gender** validation where applicable. @pytest.mark.full_model: Marks L4 nightly-only suites (e.g. `test_*_expansion.py`, doc examples).

    @pytest.mark.core_model: Marks the test as L1 or L2 level. At `--run-level core_model`, validation is limited to request success plus cheap payload checks (e.g. non-empty audio bytes, response format/content-type, non-empty diffusion outputs)—not Whisper, keyword, or accuracy gates. Deploy YAML may use `load_format: dummy` for fast PR feedback.

    @pytest.mark.parametrize: A parameterization decorator that allows abstracting test data into parameters, enabling reuse of the same test logic across different data configurations. indirect=True indicates that parameters will be passed to the fixture for processing.

    **Notes**: If you believe the test case only needs to execute basic run logic at the PR-level CI, you can mark it only with @pytest.mark.core_model. If you believe it only needs to execute deep validation at merge (L3), use @pytest.mark.advanced_model. For L4 nightly-only expansion and doc-example tests, use @pytest.mark.full_model with `--run-level full_model`. If the test case needs both basic run and deep validation, mark with @pytest.mark.core_model and the appropriate L3/L4 marker (`advanced_model` and/or `full_model`).

    **2.4.2 Test Function Definition and Documentation**

    ```python
    def test_mix_to_text_audio_001(omni_server, openai_client) -> None:
        """
        Test multi-modal input processing and text/audio output generation via OpenAI API.
        Deploy Setting: default yaml
        Input Modal: text + audio + video + image
        Output Modal: text + audio
        Input Setting: stream=True
        Datasets: single request
        """
    ```

    **Explanation**:

    **Function Naming Convention**: Uses the test_ prefix, describes the test scenario mix_to_text_audio, and the number 001 indicates the first test case for this scenario.

    **Parameter Explanation**:

    omni_server: Omni server instance obtained via fixture, containing model information and configuration.

    openai_client: Unified OpenAI client processing instance, encapsulating request sending and response validation logic.

    Docstring: Describes the test purpose, deployment settings, input/output modalities, streaming settings, and dataset type in detail, providing clear context for test maintenance.

    **2.4.3 Multimodal Data Preparation**

    ```python
    video_data_url = f"data:video/mp4;base64,{generate_synthetic_video(224, 224, 300)['base64']}"
    image_data_url = f"data:image/jpeg;base64,{generate_synthetic_image(224, 224)['base64']}"
    audio_data_url = f"data:audio/wav;base64,{generate_synthetic_audio(5, 1)['base64']}"
    ```

    **Explanation**:

    **Data Generation Functions**: Use the generate_synthetic_* series of functions to generate synthetic test data, avoiding reliance on external resources and ensuring test reproducibility and stability.

    **Parameter Explanation**:

    Video: width, height, duration_frames

    Image: width, height

    Audio: duration_seconds, channels

    **2.4.4 Request Configuration and Keyword Validation**

    ```python
    request_config = {
        "model": omni_server.model,
        "messages": messages,
        "stream": True,
        "key_words": {
            "audio": ["water", "cricket"],
            "video": ["sphere", "globe", "circle", "round"],
            "image": ["square", "quadrate"],
            "text": ["beijing"]
        },
    }
    ```

    **Explanation**:

    **Model Specification**: Uses omni_server.model to ensure the test aligns with the model configured on the server.

    **Keyword Validation Mechanism**: This is an innovative design of the template to address the specific needs of multimodal testing:

    Audio Keywords: Validate whether the generated text's description of audio content contains expected elements (e.g., "water" for water sounds, "cricket" for cricket sounds). If you provide multiple keywords, the validation is considered successful if at least one keyword is present.

    **Video Keywords**: Validate whether the generated text's description of video content contains expected elements. If you provide multiple keywords, the validation is considered successful if at least one keyword is present.

    Image Keywords: Validate whether the generated text's description of image content contains expected elements. If you provide multiple keywords, the validation is considered successful if at least one keyword is present.

    Text Keywords: Validate whether the generated text contains expected elements. If you provide multiple keywords, the validation is considered successful if at least one keyword is present.

    **2.4.5 Request Execution**

    ```python
    openai_client.send_omni_request(request_config, request_num=1)  # for omni-understanding models
    # or
    openai_client.send_diffusion_request(request_config, request_num=1)  # for diffusion models
    ```

    **Explanation**:

    **Unified Client**: Uses the OpenAIClientHandler instance to send requests. This client encapsulates error handling, retry mechanisms, and response validation logic.

    **Single Request**: The comment clearly states this is a single-request completion test. For concurrent testing, it can be extended to multiple requests using request_num = n.

    **Implicit Validation**: `send_omni_request`, `send_audio_speech_request`, and `send_diffusion_request` call `assert_*_response` helpers with the session `--run-level`. At `core_model`, checks are limited to success plus cheap payload sanity (non-empty audio/media, format/content-type, optional `min_audio_bytes`). At `advanced_model` and `full_model`, deep validation adds Whisper transcripts, keyword/similarity, diffusion dimension checks, PCM HNR, etc.

    **Audio output debugging**: Deep validation may transcribe returned audio via `convert_audio_bytes_to_text` (Whisper). If an audio keyword or text–audio similarity assertion fails, set `VLLM_OMNI_KEEP_REQUEST_MEDIA=1` before running pytest to keep the intermediate WAV files for inspection (see [Test helper environment variables](test_system_overview.md#test-helper-environment-variables)).

-   ***Run Command (L3 merge)***: `pytest -s -v /tests/e2e/online_serving/test_{model_name}.py -m advanced_model --run-level=advanced_model`

-   ***Run Command (L4 nightly expansion)***: `pytest -s -v /tests/e2e/online_serving/test_{model_name}_expansion.py -m full_model --run-level=full_model`

### L4 Level Testing - Full Functionality, Performance, and Documentation Testing

#### 3.1 Testing Purpose

L4 level testing is a comprehensive quality audit before a version release. It expands upon L3, executing ***full*** functional scenarios, conducting systematic ***performance stress tests***, and simultaneously verifying the correctness of accompanying ***example documentation***. Its purpose is to perform deep validation of the system during off-peak nighttime hours, providing quality trend reports for daytime development and data support for release decisions.



#### 3.2 Testing Content and Scope

-   ***Full Functionality Testing***: Executes all test cases defined in `test_{model_name}_expansion.py`, covering all implemented features, positive flows, boundary conditions, and exception handling.
-   ***Performance Testing***: Uses `tests/dfx/perf/tests/test_qwen3_omni_*.json` (Omni), `test_tts.json` / `test_voxcpm2.json` / `test_higgs_audio_v3.json` (TTS), and diffusion configs `tests/dfx/perf/tests/test_*_vllm_omni.json` (passed to `run_benchmark.py` or `run_diffusion_benchmark.py` via `--test-config-file` in nightly **Perf Test** steps) to drive throughput, latency, and memory benchmarks. Each JSON **case** may declare an optional top-level **`mark`** array: exactly one ``hardware_marks`` object plus pytest marker name strings (`full_model`, `omni` / `tts` / `diffusion`, …). Runners attach those marks to each parametrized `(server, benchmark index)` pair so **local** bulk runs can filter with `-m` (for example `-m "full_model and H100 and diffusion"`). Nightly CI perf jobs select workloads by **`--test-config-file`**, not `-m`. Details are in the Performance Tests example below.
-   ***Documentation Testing***: Verifies whether the example code provided to users is runnable and its results match the description.

#### 3.3 Test Directory and Execution Files

-   ***Functional Testing***: Same directories as L3.
-   ***Performance Test Configuration***: `tests/dfx/perf/tests/test_qwen3_omni_*.json`, `test_tts.json`, `test_voxcpm2.json`, `test_higgs_audio_v3.json`, and diffusion configs `tests/dfx/perf/tests/test_*_vllm_omni.json` (e.g. `test_qwen_image_vllm_omni.json`, `test_cosmos3_vllm_omni.json`). Optional per-case `mark` for local `-m` filtering is documented in Section 3.4 Performance Tests.
-   ***Documentation Example Tests***:
    -   `tests/examples/online_serving/test_{model_name}.py`
    -   `tests/examples/offline_inference/test_{model_name}.py`

#### 3.4 Execution Method and Example

-   ***Trigger Timing***: **`Nightly`**, automatically executed every night.
-   ***Execution Environment***: ***GPU*** server clusters to meet the resource demands of performance testing.
-   ***Script Example***:

??? example "Test Examples: Documentation Example Tests"

    --8<-- "docs/contributing/ci/test_examples/l4_doc_example_tests.inc.md"

??? example "Test Examples: Performance Tests"

    --8<-- "docs/contributing/ci/test_examples/l4_performance_tests.inc.md"

??? example "Test Examples: Functionality Tests"

    --8<-- "docs/contributing/ci/test_examples/l4_functionality_tests.inc.md"

-   ***Run Command***: (Specific commands would depend on the performance testing tool and configuration defined in `nightly.json`).

### L5 Level Testing - Stability and Reliability Testing

#### 4.1 Testing Purpose

L5 level testing focuses on the performance of model services under ***long-running*** and ***abnormal fault*** scenarios. It aims to uncover deep-seated issues that only manifest under sustained pressure or extreme conditions, such as memory leaks, resource contention, gradual performance degradation, and lack of fault tolerance mechanisms. This is the final, yet crucial, line of defense for ensuring service high availability and production environment robustness.



#### 4.2 Testing Content and Scope

-   ***Long-term Stability (Stability) Testing***: Uses JSON under `tests/dfx/stability/tests/` (for example `test_qwen3_omni.json` and `test_wan22.json`) to run the service under moderate load for an extended period (e.g., over 12 hours), monitoring whether metrics like memory/VRAM usage, response time, and throughput degrade over time, and whether the service process remains stable.
-   ***Reliability Testing***: Uses pytest suites under `tests/dfx/reliability/` to inject controlled faults against a **live** `vllm_omni serve` instance (same **`omni_server` / `omni_server_function`** fixture style as E2E). Current suites emphasize **GPU memory pressure** (CUDA sidecar “memory hog”), **worker / runtime process kill** (`SIGKILL` on `VLLM::Worker` for Qwen3-Omni, `multiprocessing.spawn` for Wan2.2 video workers, or `vLLM-Omni::` for HunyuanImage DiT workers), **large multimodal chat**, **`/v1/videos`**, **`/v1/images/generations`**, or **`/v1/audio/speech`** jobs under OOM, **`/health` → 503** and **fast-fail / non-hanging concurrent** requests after kill, and **OpenAI-style 5xx error contracts** (e.g. text vs text+audio under OOM). **Post-fault recovery** checks exist where enabled (some cases may be `skip` while issues are tracked). See the Reliability `<details>` block in Section 4.4 for file-level responsibilities and CI markers (`slow`, `hardware_test`, POSIX-only kill).

#### 4.3 Test Directory and Execution Files

-   ***Stability Test Configuration***: `tests/dfx/stability/tests/test_qwen3_omni.json`, `tests/dfx/stability/tests/test_wan22.json` (one JSON per model / runner family)
-   ***Reliability Test Suite*** (`tests/dfx/reliability/`):
    -   `test_reliability_qwen3_omni.py` — Qwen3-Omni chat / multimodal reliability (GPU OOM, process kill, recovery, error contract under `--async-chunk` vs default).
    -   `test_reliability_wan22.py` — Wan2.2 I2V video API reliability (`/v1/videos` under OOM and process kill, recovery).
    -   `test_reliability_hunyuan_image.py` — HunyuanImage-3.0-Instruct DiT-only reliability (`/v1/images/generations` under OOM and process kill; deploy `hunyuan_image3_dit.yaml`, H100 × 4).
    -   `test_reliability_voxcpm2.py` — VoxCPM2 TTS reliability (`/v1/audio/speech` under OOM and process kill; deploy `voxcpm2.yaml`, L4 × 1).
    -   `helpers.py` — Shared primitives used by current suites: raw HTTP probes for `/v1/chat/completions` and `/health`, OpenAI-style error parsing, GPU OOM sidecar (`inject_gpu_oom` / `stop_gpu_oom_hogs`), and `pgrep`-based process-kill injector construction (`make_process_kill_fault_injector`).
    -   `conftest.py` — `fault_injector` and `omni_server_after_fault` / `omni_server_after_fault_function` fixtures to run a callable **after** the server is ready.
    -   `README.md` — Short local run commands for this directory.

#### 4.4 Execution Method and Example

-   ***Trigger Timing***: **`Weekly`** (weekly) or **`Days before Release`** (several days before a major release). Due to long execution times, the frequency is lower.
-   ***Execution Environment***: ***GPU*** servers, requiring a stable and exclusive testing environment.
-   ***Script Example***:
<details>
<summary> Test Examples</summary>

When you want to add L5-level stability test cases, add or extend the appropriate JSON file under `tests/dfx/stability/tests/` (for example `test_qwen3_omni.json` for Omni bench traffic, or `test_wan22.json` for diffusion `/v1/videos` workloads). The following illustrates the Qwen3-Omni shape:

```json
{
    "test_name": "test_qwen3_omni_stability",
    "server_params": {
        "model": "Qwen/Qwen3-Omni-30B-A3B-Instruct",
        "stage_config_name": "qwen3_omni.yaml"
    },
    "benchmark_params": [
        {
            "dataset_name": "random",
            "backend": "openai-chat-omni",
            "endpoint": "/v1/chat/completions",
            "duration_sec": 43200,
            "request_rate": 0.5,
            "num_prompts_per_batch": 20,
            "random_input_len": 2500,
            "random_output_len": 900,
            "ignore_eos": true,
            "percentile-metrics": "ttft,tpot,itl,e2el,audio_rtf,audio_ttfp,audio_duration"
        }
    ]
}
```

##### Parameter Explanation

***Overview***

| Field            | Required | Description                                                                 |
| ---------------- | -------- | --------------------------------------------------------------------------- |
| test_name        | Yes      | Unique identifier for the stability test case                               |
| server_params    | Yes      | Server-side configuration parameters (model, stage configuration, etc.)     |
| benchmark_params | Yes      | Stability benchmark running parameters (supports multiple configurations)   |

##### server_params Configuration

###### Basic Parameters

| Parameter         | Required | Example                            | Description                         |
| ----------------- | -------- | ---------------------------------- | ----------------------------------- |
| model             | Yes      | "Qwen/Qwen3-Omni-30B-A3B-Instruct" | Model name or path                  |
| stage_config_name | Yes      | "qwen3_omni.yaml"                  | Stage configuration file name       |

###### Dynamic Configuration (update/delete)

Supports incremental modifications based on the basic configuration:

| Operation | Description                          |
| --------- | ------------------------------------ |
| update    | Update or add configuration items    |
| delete    | Delete specified configuration items |

***Example***:
You can refer to Test Examples in L4 §3.4

##### benchmark_params Configuration

For stability testing, the key parameters are:

-   **duration_sec**: Total duration (in seconds) during which benchmark traffic is sent. The stability benchmark will keep sending batches until this duration is reached.
-   **request_rate** / **max_concurrency**: Exactly one of them must be specified. They control how the traffic is generated for each batch:
    -   `request_rate`: Number of requests per second. The benchmark will send `num_prompts_per_batch` requests at the given rate.
    -   `max_concurrency`: Maximum number of concurrent requests. When this is used, `request_rate` is set to `inf` internally.
-   **num_prompts_per_batch**: Number of prompts sent in each batch. Multiple batches will be executed sequentially within `duration_sec`.

All other optional parameters follow the same rules as in L4 §3.4.

</details>

<details>
<summary> Reliability test suite (<code>tests/dfx/reliability</code>)</summary>

##### Purpose and relationship to stability

Reliability tests are **short fault-injection** integration runs (L5 **(b)** in `tests/dfx/reliability/README.md`). They complement **stability** JSON-driven long runs: instead of hours of steady traffic, they **perturb** the server (GPU OOM sidecar, fatal signals on selected processes) and check **failure mode** and **latency bounds** (e.g. chat or `/v1/videos` must not hang under concurrent fault-time load).

##### Directory layout

| Path | Responsibility |
| ---- | -------------- |
| `helpers.py` | Shared helpers used by current reliability suites: raw `POST`/`GET` probes (`/v1/chat/completions`, `/health`), OpenAI error parsing (`extract_openai_error_contract_from_bytes`), GPU OOM sidecar lifecycle (`inject_gpu_oom`, `stop_gpu_oom_hogs`), and process-kill injector builder (`make_process_kill_fault_injector`). |
| `conftest.py` | Pytest fixtures: indirect `fault_injector`, `omni_server_after_fault` / `omni_server_after_fault_function` (run injector after server is ready, then yield server). |
| `test_reliability_qwen3_omni.py` | Qwen3-Omni: OOM vs **text vs text+audio** error contract, large multimodal chat under OOM, concurrent pressure, **SIGKILL** on `VLLM::Worker`, `/health` → 503 + fast-fail + concurrent chat; optional OOM recovery scenario (may be skipped while tracked in issues). |
| `test_reliability_wan22.py` | Wan2.2 I2V: large `/v1/videos` under OOM, **SIGKILL** on `multiprocessing.spawn` chain, health / fast-fail / concurrent video requests; optional recovery test (may be skipped). |
| `test_reliability_hunyuan_image.py` | HunyuanImage DiT-only: large `/v1/images/generations` under OOM, **SIGKILL** on `vLLM-Omni::` workers and serve/tree targets, health / fast-fail / concurrent image requests; some OOM/recovery cases may be skipped while tracked in issues. |
| `test_reliability_voxcpm2.py` | VoxCPM2: `/v1/audio/speech` under OOM (error contract), **SIGKILL** on `VLLM::` workers and serve/tree targets, health / fast-fail / concurrent speech requests; some OOM cases may be skipped while tracked in issues. |
| `README.md` | Minimal run / collect examples. |

##### Parametrization and markers

- Each test module defines a **`RELIABILITY_SCENARIOS`** list (`test_name`, `server_params`: model, `stage_config_name` or diffusion `server_args`, etc.). **`create_reliability_omni_server_params()`** in `tests/dfx/conftest.py` resolves stage paths (including XPU substitutions where applicable) and builds **`OmniServerParams`** lists consumed by **`@pytest.mark.parametrize(..., indirect=True)`** on `omni_server` or `omni_server_function`.
- Cases are tagged **`@pytest.mark.slow`** for weekly / selective CI. GPU-heavy suites use **`@hardware_test(res={"cuda": "H100"}, num_cards=...)`** or **`@hardware_test(res={"cuda": "L4"}, num_cards=1)`** (Qwen3-Omni **2**× H100; Wan2.2 **1**× H100; HunyuanImage DiT **4**× H100; VoxCPM2 **1**× L4).
- **Process-kill** tests use **`@pytest.mark.skipif(os.name == "nt", ...)`** because injection uses POSIX **`pgrep` / `kill`**.

##### CI trigger

Weekly Buildkite (`.buildkite/cuda/test-weekly.yml`) runs one step per model suite (trigger: `WEEKLY=1` or PR label `weekly-test`), for example:

| Buildkite step | Test file | CI hardware |
| -------------- | --------- | ----------- |
| Reliability Test - qwen3-omni | `test_reliability_qwen3_omni.py` | H100 × 2 (`mithril-h100-pool`) |
| Reliability Test - wan22 | `test_reliability_wan22.py` | H100 × 2 (`mithril-h100-pool`) |
| Reliability Test - hunyuan-image | `test_reliability_hunyuan_image.py` | H100 × 4 (`mithril-h100-pool`) |
| Reliability Test - voxcpm2 | `test_reliability_voxcpm2.py` | L4 × 1 (`gpu_1_queue`) |

```bash
pytest -s -v tests/dfx/reliability/test_reliability_qwen3_omni.py -m "slow"
pytest -s -v tests/dfx/reliability/test_reliability_wan22.py -m "slow"
pytest -s -v tests/dfx/reliability/test_reliability_hunyuan_image.py -m "slow"
pytest -s -v tests/dfx/reliability/test_reliability_voxcpm2.py -m "slow"
```

##### Local commands

```bash
pytest --collect-only tests/dfx/reliability
pytest -s -v tests/dfx/reliability/test_reliability_qwen3_omni.py -m slow
pytest -s -v tests/dfx/reliability/test_reliability_wan22.py -m slow
pytest -s -v tests/dfx/reliability/test_reliability_hunyuan_image.py -m slow
pytest -s -v tests/dfx/reliability/test_reliability_voxcpm2.py -m slow
```

##### Adding a new model suite

1. Add `test_reliability_<model>.py` under `tests/dfx/reliability/`.
2. Define **`RELIABILITY_SCENARIOS`** and pass them through **`create_reliability_omni_server_params()`** with the correct deploy or e2e stage-config directory (same pattern as existing files).
3. Reuse **`helpers`** for OOM / kill / raw HTTP; prefer **`assert_fault_exception()`** and **`resolve_oom_device_spec()`** from `tests/dfx/conftest.py` for consistent device selection vs stage YAML.
4. Register **`slow`** (and **`hardware_test`** if needed); extend **`.buildkite/cuda/test-weekly.yml`** when the suite should run in weekly L5.

</details>

-   -   ***Stability***: `pytest -s -v tests/dfx/stability/scripts/test_stability_qwen3_omni.py` or `pytest -s -v tests/dfx/stability/scripts/test_stability_wan22.py` (or add `test_stability_<model>.py` alongside a matching JSON config)
    -   ***Reliability***: `pytest -s -v tests/dfx/reliability/test_reliability_<model>.py -m slow` (current suites: `qwen3_omni`, `wan22`, `hunyuan_image`, `voxcpm2`; add `test_reliability_<suite>.py` and a matching step in `.buildkite/cuda/test-weekly.yml` for new models)