PyProxyFS

PyProxyFS is a proxy filesystem interface with a native filesystem implementation and a very simple test in-memory filesystem.

The aim of pyproxyfs is to provide a filesystem class that you can use for doing much of your file handling... but that can easi;ly be mocked for specific testing purposes.

If, instead of using open, os.rename and os.listdir you use the pyproxyfs equivalents you can expect to be able to make a simple filesystem using the builtin TestFS class and write tests around that.

For example:

def show_conf_files(dirtolist, filesystem=None):
 from pyproxyfs import Filesystem
 if not filesystem:
 filesystem = Filesystem()
 files = filesystem.listdir(dirtolist)
 import re
 cfgpat = re.compile(".*\\.cfg$")
 cfg_files = [fn for fn in files if cfgpat.match(fn)]
 return cfg_files

this might be your application code.

You could then test it relatively simply:

def test_show_conf_files():
 """
>>> test_show_conf_files()
['a.cfg', 'b.cfg']
"""
 from pyproxyfs import TestFS
 fs = TestFS({
 "somedir/a.cfg": "",
 "somedir/a.txt": "",
 "somedir/b.cfg": "",
 "somedir/run.py": ""
 })
 return show_conf_files("somedir", filesystem=fs)

Requirements:

• Python

Limitations:

• The pyproxyfs is not designed to be a full filesystem proxy, it's just a simple and quick way to test.
• There is no way to write to the TestFS system yet; native filesystem writes work through the proxy tho as it just uses open directly.