Add more tests

Author: vstinner

Lib/test/test_capi/test_file.py

@@ -1,23 +1,55 @@
 import os
 import unittest
-from test.support import import_helper
+from test import support
+from test.support import import_helper, os_helper
 
 _testcapi = import_helper.import_module('_testcapi')
 
 
 class CAPIFileTest(unittest.TestCase):
     def test_py_fopen(self):
+        # Test Py_fopen() and Py_fclose()
         for filename in (__file__, os.fsencode(__file__)):
             with self.subTest(filename=filename):
                 content = _testcapi.py_fopen(filename, "rb")
                 with open(filename, "rb") as fp:
                     self.assertEqual(fp.read(256), content)
 
+        with open(__file__, "rb") as fp:
+            content = fp.read()
+        for filename in (
+            os_helper.TESTFN,
+            os.fsencode(os_helper.TESTFN),
+            os_helper.TESTFN_UNDECODABLE,
+            os_helper.TESTFN_UNENCODABLE,
+        ):
+            with self.subTest(filename=filename):
+                try:
+                    with open(filename, "wb") as fp:
+                        fp.write(content)
+
+                    content = _testcapi.py_fopen(filename, "rb")
+                    with open(filename, "rb") as fp:
+                        self.assertEqual(fp.read(256), content[:256])
+                finally:
+                    os_helper.unlink(filename)
+
+        # embedded null character/byte in the filename
+        with self.assertRaises(ValueError):
+            _testcapi.py_fopen("a\x00b", "rb")
+        with self.assertRaises(ValueError):
+            _testcapi.py_fopen(b"a\x00b", "rb")
+
         for invalid_type in (123, object()):
             with self.subTest(filename=invalid_type):
                 with self.assertRaises(TypeError):
                     _testcapi.py_fopen(invalid_type, "r")
 
+        if support.MS_WINDOWS:
+            with self.assertRaises(OSError):
+                # On Windows, the file mode is limited to 10 characters
+                _testcapi.py_fopen(__file__, "rt+, ccs=UTF-8")
+
 
 if __name__ == "__main__":
     unittest.main()