【Hackathon 9th No.70】supplementary unit test for CPUPlatform and CUDAPlatform (#3580)

* 功能模块 CUDAPlatform、CPUPlatform 单测补充

* update the "is_cuda" to "is_cuda_and_available"

* fix pre-commit

---------

Co-authored-by: Tao Luo <luotao02@baidu.com>

tests/platforms/test_platforms.py

@@ -0,0 +1,86 @@
+"""
+# Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+
+import unittest
+from unittest.mock import patch
+
+from fastdeploy.platforms.base import _Backend
+from fastdeploy.platforms.cpu import CPUPlatform
+from fastdeploy.platforms.cuda import CUDAPlatform
+
+
+class TestCPUPlatform(unittest.TestCase):
+    def setUp(self):
+        self.platform = CPUPlatform()
+
+    @patch("paddle.device.get_device", return_value="cpu")
+    def test_is_cpu_and_available(self, mock_get_device):
+        """
+        Check hardware type (CPU) and availability
+        """
+        self.assertTrue(self.platform.is_cpu())
+        self.assertTrue(self.platform.available())
+
+    def test_attention_backend(self):
+        """CPUPlatform attention_backend should return empty string"""
+        self.assertEqual(self.platform.get_attention_backend_cls(None), "")
+
+
+class TestCUDAPlatform(unittest.TestCase):
+    def setUp(self):
+        self.platform = CUDAPlatform()
+
+    @patch("paddle.is_compiled_with_cuda", return_value=True)
+    @patch("paddle.device.get_device", return_value="cuda")
+    @patch("paddle.static.cuda_places", return_value=[0])
+    def test_is_cuda_and_available(self, mock_get_device, mock_is_cuda, mock_cuda_places):
+        """
+        Check hardware type (CUDA) and availability
+        """
+        self.assertTrue(self.platform.is_cuda())
+        self.assertTrue(self.platform.available())
+
+    def test_attention_backend_valid(self):
+        """
+        CUDAPlatform should return correct backend class name for valid backends
+        """
+        self.assertIn(
+            "PaddleNativeAttnBackend",
+            self.platform.get_attention_backend_cls(_Backend.NATIVE_ATTN),
+        )
+        self.assertIn(
+            "AppendAttentionBackend",
+            self.platform.get_attention_backend_cls(_Backend.APPEND_ATTN),
+        )
+        self.assertIn(
+            "MLAAttentionBackend",
+            self.platform.get_attention_backend_cls(_Backend.MLA_ATTN),
+        )
+        self.assertIn(
+            "FlashAttentionBackend",
+            self.platform.get_attention_backend_cls(_Backend.FLASH_ATTN),
+        )
+
+    def test_attention_backend_invalid(self):
+        """
+        CUDAPlatform should raise ValueError for invalid backend
+        """
+        with self.assertRaises(ValueError):
+            self.platform.get_attention_backend_cls("INVALID_BACKEND")
+
+
+if __name__ == "__main__":
+    unittest.main()