[Diffusion] DreamZero world model integration with CFG parallel + OpenPI serving (#2162)

Signed-off-by: Meng <meng_chen99@163.com>
Signed-off-by: Yangshen Deng <yangshen.d@outlook.com>
Signed-off-by: Suli Wang <50828270+wsl2000@users.noreply.github.com>
Co-authored-by: Meng <meng_chen99@163.com>
Co-authored-by: Suli Wang <50828270+wsl2000@users.noreply.github.com>
Co-authored-by: amy-why-3459 <wuhaiyan17@huawei.com>

tests/dreamzero/test_openpi_client_helper.py

@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+import numpy as np
+import pytest
+
+from tests.dreamzero import openpi_client_helper
+
+pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
+
+
+class FakeMsgpackNumpy:
+    payloads = {}
+
+    @staticmethod
+    def packb(obj):
+        key = str(len(FakeMsgpackNumpy.payloads)).encode()
+        FakeMsgpackNumpy.payloads[key] = obj
+        return key
+
+    @staticmethod
+    def unpackb(data):
+        return FakeMsgpackNumpy.payloads[data]
+
+
+def test_decode_action_response_surfaces_structured_error(monkeypatch):
+    monkeypatch.setattr(openpi_client_helper, "msgpack_numpy", FakeMsgpackNumpy)
+    payload = FakeMsgpackNumpy.packb(
+        {
+            "type": "error",
+            "message": "Internal inference error",
+        }
+    )
+
+    with pytest.raises(RuntimeError, match="Internal inference error"):
+        openpi_client_helper._decode_action_response(payload)
+
+
+def test_decode_action_response_converts_action_payload_to_float32(monkeypatch):
+    monkeypatch.setattr(openpi_client_helper, "msgpack_numpy", FakeMsgpackNumpy)
+    payload = FakeMsgpackNumpy.packb(np.asarray([[1.0, 2.0]], dtype=np.float64))
+
+    actions = openpi_client_helper._decode_action_response(payload)
+
+    assert actions.dtype == np.float32
+    np.testing.assert_array_equal(actions, np.asarray([[1.0, 2.0]], dtype=np.float32))