Added pytest plugin support

.travis.yml

@@ -27,5 +27,8 @@ python:
 install:
   - if [[ $TRAVIS_PYTHON_VERSION == 2.6 ]]; then pip install importlib unittest2; fi
   - pip install -r requirements.txt
+  - pip install .
 
-script: ./all_tests.py
+script:
+  - ./all_tests.py
+  - py.test pytest_plugin_test.py

README.md

@@ -43,6 +43,21 @@ with patch('mymodule.glob', glob):
     print(glob.glob('/var/data/xx*'))
 ```
 
+### Usage as a Pytest Plugin
+
+Installation of pyfakefs also provides a [PyTest](doc.pytest.org) plugin. The plugin makes the `fs`
+fixture available for any test. For example:
+
+```
+def my_fakefs_test(fs):
+    # "fs" is the reference to the fake file system
+    fs.CreateFile('/var/data/xx1.txt')
+    assert os.path.exists('/var/data/xx1.txt')
+```
+
+Similar to the unittest class (`fake_filesystem_unittest.TestCase`), the `fs` fixture stubs
+out all file system functions and modules. 
+
 ## Continuous Integration
 
 pyfakefs is automatically tested with Python 2.6 and above, and it is currently

pyfakefs/pytest_plugin.py

@@ -0,0 +1,25 @@
+"""A pytest plugin for using pyfakefs as a fixture
+
+When pyfakefs is installed, the "fs" fixture becomes avaialable.
+
+:Usage:
+
+def my_fakefs_test(fs):
+    fs.CreateFile('/var/data/xx1.txt')
+    assert os.path.exists('/var/data/xx1.txt')
+"""
+import py
+import pytest
+from pyfakefs.fake_filesystem_unittest import Patcher
+
+
+Patcher.SKIPMODULES.add(py)  # Ignore pytest components when faking filesystem
+
+
+@pytest.fixture
+def fs(request):
+    """ Fake filesystem. """
+    patcher = Patcher()
+    patcher.setUp()
+    request.addfinalizer(patcher.tearDown)
+    return patcher.fs

pytest_plugin_test.py

@@ -0,0 +1,7 @@
+"""Tests that the pytest plugin properly provides the "fs" fixture"""
+import os
+
+
+def test_fs_fixture(fs):
+    fs.CreateFile('/var/data/xx1.txt')
+    assert os.path.exists('/var/data/xx1.txt')

setup.py

@@ -66,6 +66,9 @@
 
 params = dict(
     name=NAME,
+    entry_points={
+        'pytest11': ['pytest_fakefs = pyfakefs.pytest_plugin'],
+    },
     version=__version__,
     install_requires=REQUIRES,
 

tox.ini

@@ -2,7 +2,9 @@
 envlist=py26,py27,py32,py33,pypy
 
 [testenv]
-commands=python all_tests.py
+commands=
+    python all_tests.py
+    py.test pytest_plugin_test.py
 
 [testenv:py26]
 deps=unittest2