From 6bc3162256acc9364a096ba1d58883c9cb599ce5 Mon Sep 17 00:00:00 2001
From: mrbean-bremen <mrbean-bremen@users.noreply.github.com>
Date: Mon, 11 Jul 2022 18:31:30 +0200
Subject: [PATCH] Overwrite instance check for PathLibPathModule (#685)

- fixes #666 without the need to skip _pytest.pathlib patching
- add module and session scoped fs fixtures
- fixes #684
---
 CHANGES.md                                    |  8 ++++++
 docs/usage.rst                                |  4 +++
 pyfakefs/fake_pathlib.py                      |  5 ++++
 pyfakefs/pytest_plugin.py                     | 27 ++++++++++++++++---
 .../tests/fake_filesystem_unittest_test.py    | 12 +++++++++
 5 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index a07e2b44..89a49e68 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -18,6 +18,14 @@ The released versions correspond to PyPi releases.
 ### New Features
 * added some support for the upcoming Python version 3.11
   (see [#677](../../issues/677))
+* added convenience fixtures for module- and session based `fs` fixtures
+  (`fs_module` and `fs_session`)
+
+### Fixes
+* fixed an incompatibility of `tmpdir` (and probably other fixtures) with the 
+  module-scoped version of `fs`; had been introduced in 
+  pyfakefs 4.5.5 by the fix for [#666](../../issues/666)
+  (see [#684](../../issues/684))
 
 ## [Version 4.5.6](https://pypi.python.org/pypi/pyfakefs/4.5.6) (2022-03-17)
 Fixes a regression which broke tests with older pytest versions (< 3.9).
diff --git a/docs/usage.rst b/docs/usage.rst
index b2ec2fa1..2a2631ec 100644
--- a/docs/usage.rst
+++ b/docs/usage.rst
@@ -64,6 +64,10 @@ tests:
         """
         yield fs
 
+For convenience, module- and session-scoped fixtures with the same
+functionality are provided, named ``fs_module`` and ``fs_session``,
+respectively.
+
 
 Patch using fake_filesystem_unittest.Patcher
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/pyfakefs/fake_pathlib.py b/pyfakefs/fake_pathlib.py
index e1179a28..efa07067 100644
--- a/pyfakefs/fake_pathlib.py
+++ b/pyfakefs/fake_pathlib.py
@@ -792,6 +792,11 @@ def __call__(self, *args, **kwargs):
     def __getattr__(self, name):
         return getattr(self.fake_pathlib.Path, name)
 
+    @classmethod
+    def __instancecheck__(cls, instance):
+        # fake the inheritance to pass isinstance checks - see #666
+        return isinstance(instance, PurePath)
+
 
 class RealPath(pathlib.Path):
     """Replacement for `pathlib.Path` if it shall not be faked.
diff --git a/pyfakefs/pytest_plugin.py b/pyfakefs/pytest_plugin.py
index 3d3306cd..7a3103f6 100644
--- a/pyfakefs/pytest_plugin.py
+++ b/pyfakefs/pytest_plugin.py
@@ -8,7 +8,6 @@ def my_fakefs_test(fs):
     fs.create_file('/var/data/xx1.txt')
     assert os.path.exists('/var/data/xx1.txt')
 """
-import _pytest
 import py
 import pytest
 
@@ -16,8 +15,6 @@ def my_fakefs_test(fs):
 
 Patcher.SKIPMODULES.add(py)
 Patcher.SKIPMODULES.add(pytest)
-if hasattr(_pytest, "pathlib"):
-    Patcher.SKIPMODULES.add(_pytest.pathlib)
 
 
 @pytest.fixture
@@ -31,3 +28,27 @@ def fs(request):
     patcher.setUp()
     yield patcher.fs
     patcher.tearDown()
+
+
+@pytest.fixture(scope="module")
+def fs_module(request):
+    """ Module-scoped fake filesystem fixture. """
+    if hasattr(request, 'param'):
+        patcher = Patcher(*request.param)
+    else:
+        patcher = Patcher()
+    patcher.setUp()
+    yield patcher.fs
+    patcher.tearDown()
+
+
+@pytest.fixture(scope="session")
+def fs_session(request):
+    """ Session-scoped fake filesystem fixture. """
+    if hasattr(request, 'param'):
+        patcher = Patcher(*request.param)
+    else:
+        patcher = Patcher()
+    patcher.setUp()
+    yield patcher.fs
+    patcher.tearDown()
diff --git a/pyfakefs/tests/fake_filesystem_unittest_test.py b/pyfakefs/tests/fake_filesystem_unittest_test.py
index 97b5f7b6..4627b098 100644
--- a/pyfakefs/tests/fake_filesystem_unittest_test.py
+++ b/pyfakefs/tests/fake_filesystem_unittest_test.py
@@ -32,6 +32,8 @@
 from pathlib import Path
 from unittest import TestCase, mock
 
+import pytest
+
 import pyfakefs.tests.import_as_example
 import pyfakefs.tests.logsio
 from pyfakefs import fake_filesystem_unittest, fake_filesystem
@@ -879,5 +881,15 @@ def test_is_absolute(self, fs):
         self.assertTrue(pathlib.Path(".").absolute().is_absolute())
 
 
+class TestModuleScopedFsWithTmpdir:
+    @pytest.fixture(autouse=True)
+    def test_internal(self, tmpdir):
+        yield
+
+    def test_fail(self, fs_module):
+        # Regression test for #684
+        assert True
+
+
 if __name__ == "__main__":
     unittest.main()