add test case

tests/test_system.py

@@ -1,12 +1,15 @@
 import os
 import stat
 import time
+import tempfile
+
 import pytest
+
 from pydu.platform import WINDOWS
 from pydu.system import makedirs, remove, removes, open_file, copy, touch, which
 
 if not WINDOWS:
-    from pydu.system import link, symlink
+    from pydu.system import link, symlink, chmod
 
 
 class TestMakeDirs:
@@ -350,3 +353,23 @@ def test_chcp():
         assert str(cp) == '<active code page number: 437>'
     finally:
         windll.kernel32.SetConsoleOutputCP(origin_code)
+
+
+@pytest.mark.skipif(WINDOWS, reason='Not support on windows')
+class TestChmod:
+    def test_chmod_file(self):
+        _, t_file = tempfile.mkstemp()
+        chmod(t_file, 755)
+        assert oct(os.stat(t_file).st_mode)[-3:] == '755'
+
+    def test_chmod_dir(self):
+        t_dir = tempfile.mkdtemp()
+        for _ in range(5):
+            tempfile.mkstemp(dir=t_dir)
+        chmod(t_dir, 755)
+        for root, _, files in os.walk(t_dir):
+            root_path = os.path.abspath(root)
+            assert oct(os.stat(root_path).st_mode)[-3:0] == '755'
+            for file_ in files:
+                assert oct(os.stat(os.path.join(root_path, file_)).st_mode)[-3:0] == '755'
+