[torch.compile] Sequence Parallelism threshold compile ranges (#28672)

Signed-off-by: jasonlizhengjian <jasonlizhengjian@gmail.com>
Signed-off-by: Jason Li <jasonlizhengjian@gmail.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Luka Govedič <ProExpertProg@users.noreply.github.com>

tests/compile/conftest.py

@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from contextlib import contextmanager
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from vllm.platforms.interface import DeviceCapability
+
+
+@pytest.fixture
+def mock_cuda_platform():
+    """
+    Fixture that returns a factory for creating mocked CUDA platforms.
+
+    Usage:
+        def test_something(mock_cuda_platform):
+            with mock_cuda_platform(is_cuda=True, capability=(9, 0)):
+                # test code
+    """
+
+    @contextmanager
+    def _mock_platform(is_cuda: bool = True, capability: tuple[int, int] | None = None):
+        mock_platform = MagicMock()
+        mock_platform.is_cuda.return_value = is_cuda
+        if capability is not None:
+            mock_platform.get_device_capability.return_value = DeviceCapability(
+                *capability
+            )
+        with patch("vllm.platforms.current_platform", mock_platform):
+            yield mock_platform
+
+    return _mock_platform