Fix patching "open" calls in modules with a name ending with "io"

- adapted test that sometimes fail due to timing issue
- fixes #569

Author: mrbean-bremen

CHANGES.md

@@ -3,6 +3,10 @@ The released versions correspond to PyPi releases.
 
 ## Version 4.4.0 (as yet unreleased)
 
+### Fixes
+* `open` calls had not been patched for modules with a name ending with "io"
+  (see [#569](../../issues/569))
+
 ## [Version 4.3.1](https://pypi.python.org/pypi/pyfakefs/4.3.1) (2020-11-23)
 
 This is an update to the performance release, with more setup caching and the

pyfakefs/fake_filesystem.py

@@ -4563,7 +4563,8 @@ def open(self, file, mode='r', buffering=-1, encoding=None,
         stack = traceback.extract_stack(limit=2)
         module_name = os.path.splitext(stack[0].filename)[0]
         module_name = module_name.replace(os.sep, '.')
-        if any([module_name.endswith(sn) for sn in self.skip_names]):
+        if any([module_name == sn or module_name.endswith('.' + sn)
+                for sn in self.skip_names]):
             return io.open(file, mode, buffering, encoding, errors,
                            newline, closefd, opener)
         fake_open = FakeFileOpen(self.filesystem)

pyfakefs/fake_filesystem_unittest.py

@@ -432,7 +432,6 @@ def __init__(self, additional_skip_names=None,
         self._skip_names = self.SKIPNAMES.copy()
         # save the original open function for use in pytest plugin
         self.original_open = open
-        self.fake_open = None
         self.patch_open_code = patch_open_code
 
         if additional_skip_names is not None:
@@ -701,7 +700,6 @@ def _refresh(self):
             if hasattr(self.fake_modules[name], 'skip_names'):
                 self.fake_modules[name].skip_names = self._skip_names
         self.fake_modules[PATH_MODULE] = self.fake_modules['os'].path
-        self.fake_open = fake_filesystem.FakeFileOpen(self.fs)
         for name in self._unfaked_module_classes:
             self.unfaked_modules[name] = self._unfaked_module_classes[name]()
 

pyfakefs/tests/fake_filesystem_unittest_test.py

@@ -32,6 +32,7 @@
 from unittest import TestCase, mock
 
 import pyfakefs.tests.import_as_example
+import pyfakefs.tests.logsio
 from pyfakefs import fake_filesystem_unittest, fake_filesystem
 from pyfakefs.extra_packages import pathlib
 from pyfakefs.fake_filesystem import OSType
@@ -343,6 +344,13 @@ def test_open_fails(self):
         with self.assertRaises(OSError):
             pyfakefs.tests.import_as_example.open_this_file()
 
+    def test_open_patched_in_module_ending_with_io(self):
+        # regression test for #569
+        file_path = '/foo/bar'
+        self.fs.create_file(file_path, contents=b'abc')
+        contents = pyfakefs.tests.logsio.file_contents(file_path)
+        self.assertEqual(b'abc', contents)
+
 
 class AdditionalSkipNamesTest(fake_filesystem_unittest.TestCase):
     """Make sure that modules in additional_skip_names are not patched.

pyfakefs/tests/fake_open_test.py

@@ -1895,7 +1895,7 @@ def test_chdir_uses_open_fd_as_path(self):
             # unclear behavior with PyPi
             self.skip_real_fs()
         self.assert_raises_os_error(
-            [errno.ENOTDIR, errno.EBADF], self.os.chdir, 10)
+            [errno.ENOTDIR, errno.EBADF], self.os.chdir, 500)
         dir_path = self.make_path('foo', 'bar')
         self.create_dir(dir_path)
 

pyfakefs/tests/fake_stat_time_test.py

@@ -334,8 +334,8 @@ def check_open_write_flush_close_w_mode(self):
         """
         before, opened, written, flushed, closed = self.open_write_flush()
 
-        self.assertLessExceptWindows(before.st_ctime, opened.st_ctime)
-        self.assertLessExceptWindows(written.st_ctime, flushed.st_ctime)
+        self.assertLessEqual(before.st_ctime, opened.st_ctime)
+        self.assertLessEqual(written.st_ctime, flushed.st_ctime)
         self.assertEqual(opened.st_ctime, written.st_ctime)
         self.assertEqual(flushed.st_ctime, closed.st_ctime)
 

pyfakefs/tests/logsio.py

@@ -0,0 +1,22 @@
+# 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.
+
+"""
+Example module that is used for a regression test where a module with
+a name ending with "io" was skipped from patching (see #569).
+"""
+
+
+def file_contents(path):
+    """Return the contents of the given path as byte array."""
+    with open(path, 'rb') as f:
+        return f.read()