test: skip GPU tests when PyTorch is missing

Keep the test suite reporting an intentional skip instead of crashing in environments without torch.

Author: shijiashuai

tests/conftest.py

@@ -3,9 +3,13 @@
 """
 
 import pytest
-import torch
 import numpy as np
 
+try:
+    import torch
+except ImportError:  # pragma: no cover - environment-dependent guard
+    pytest.skip("PyTorch is not installed", allow_module_level=True)
+
 
 def pytest_configure(config):
     """Configure pytest markers."""

tests/test_attention.py

@@ -4,9 +4,13 @@
 """
 
 import pytest
-import torch
 from hypothesis import given, settings, strategies as st
 
+try:
+    import torch
+except ImportError:  # pragma: no cover - environment-dependent guard
+    pytest.skip("PyTorch is not installed", allow_module_level=True)
+
 from conftest import assert_close, compute_attention_reference
 
 

tests/test_gemm.py

@@ -4,9 +4,13 @@
 """
 
 import pytest
-import torch
 from hypothesis import given, settings, strategies as st
 
+try:
+    import torch
+except ImportError:  # pragma: no cover - environment-dependent guard
+    pytest.skip("PyTorch is not installed", allow_module_level=True)
+
 from conftest import assert_close
 
 

tests/test_interface.py

@@ -4,9 +4,13 @@
 """
 
 import pytest
-import torch
 from hypothesis import given, settings, strategies as st
 
+try:
+    import torch
+except ImportError:  # pragma: no cover - environment-dependent guard
+    pytest.skip("PyTorch is not installed", allow_module_level=True)
+
 from conftest import assert_close