[Feature][LingBot World]stepwise execution (#6844)

Signed-off-by: BruceLoveDecimal <liuqihao970610@gmail.com>
Signed-off-by: liuqihao <liuqihao970610@gmail.com>

tests/engine/test_diffusion_streaming_output_kwarg.py

@@ -0,0 +1,79 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM-Omni project
+"""``diffusion_streaming_output`` must reach a diffusion stage as ``streaming_output``.
+
+The public AsyncOmni/serve kwarg and the stage schema field have different
+names, and the two config paths translate it in different places: the
+unregistered single-stage fallback writes it into the default stage config,
+while a registered pipeline resolves through ``StageConfigFactory``, which drops
+keys the stage schema does not know. Without the mirror in
+``_resolve_stage_configs`` a registered pipeline (LingBot World stepwise) serves
+only its final chunk instead of streaming one per step.
+"""
+
+from __future__ import annotations
+
+from types import SimpleNamespace
+from typing import Any
+
+import pytest
+
+from vllm_omni.engine.async_omni_engine import AsyncOmniEngine
+
+pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
+
+
+def _resolve(monkeypatch, kwargs: dict[str, Any]) -> dict[str, Any]:
+    """Run ``_resolve_stage_configs`` and return the kwargs it forwarded."""
+
+    seen: dict[str, Any] = {}
+
+    def _fake_load(model, forwarded_kwargs, **_: Any):
+        seen.update(forwarded_kwargs)
+        return "config.yaml", [], None
+
+    monkeypatch.setattr(
+        "vllm_omni.engine.async_omni_engine.load_and_resolve_stage_configs",
+        _fake_load,
+    )
+    engine = SimpleNamespace(
+        _create_default_diffusion_stage_cfg=AsyncOmniEngine._create_default_diffusion_stage_cfg,
+        _apply_strategy_lb_policy=lambda *_args, **_kw: None,
+    )
+    AsyncOmniEngine._resolve_stage_configs(
+        engine,
+        "some/model",
+        kwargs,
+        trust_remote_code=None,
+    )
+    return seen
+
+
+def test_registered_pipeline_receives_streaming_output(monkeypatch) -> None:
+    forwarded = _resolve(monkeypatch, {"diffusion_streaming_output": True})
+
+    assert forwarded["streaming_output"] is True
+
+
+def test_disabled_kwarg_does_not_override_the_deploy_config(monkeypatch) -> None:
+    # ``serve`` always carries the flag's ``False`` default; mirroring it would
+    # silently turn streaming off for a deploy YAML that asks for it.
+    forwarded = _resolve(monkeypatch, {"diffusion_streaming_output": False})
+
+    assert "streaming_output" not in forwarded
+
+
+def test_explicit_streaming_output_wins(monkeypatch) -> None:
+    forwarded = _resolve(
+        monkeypatch,
+        {"diffusion_streaming_output": True, "streaming_output": False},
+    )
+
+    assert forwarded["streaming_output"] is False
+
+
+@pytest.mark.parametrize("enabled", [True, False])
+def test_unregistered_fallback_stage_carries_the_flag(enabled: bool) -> None:
+    stage_cfg = AsyncOmniEngine._create_default_diffusion_stage_cfg({"diffusion_streaming_output": enabled})[0]
+
+    assert stage_cfg["engine_args"]["streaming_output"] is enabled