Revert to using mox.stubout instead of mock.patch

[jmcgeheeiv]

A few months ago, in pyfakefs.pyfakefs_unittest._Patcher I replaced mox with unittest.mock. mox worked fine, but mock seemed like a more reliable dependency:

• mox is seemingly abandoned while mock is now part of the standard library
• mox does not support Python 3
• The OpenStack people created mox3 to support Python 3, but it is marked with the omimous comment, "Use at your own risk". Moreover, OpenStack stopped using mox3.

Now we are seeing all kinds of trouble caused by mock module bug 250:

• pyfakefs issue pyfakefs is incompatible with pytest #43
• pyfakefs issue fake_filesystem_unittest.py uses python2 __builtin__ #46

pyfakefs used only one small part of mox, mox.stubout. I do not care to depend on unmaintained mox, (or to take on maintenance of the mox3 module as a whole), so I am considering salvaging just the part of mox3 that pyfakefs needs:

1. Take just mox3.stubout.py and its test from mox3
2. Add it to pyfakefs as pyfakefs.stubout
3. Revert to using pyfakefs.stubout as I used mox.stubout in earlier versions, eliminating the dependency on both mock and mox

Please tell me what you think of this plan.

[tomviner]

Given the issues we're seeing, this sounds like the best option.

[robintw]

This sounds like a very good way forward.

(In the meantime, is there anything I can do myself to fix this? I'm really struggling with fake_filesystem_unittest.py at the moment)

[jmcgeheeiv]

Robin, which issue it it that you are facing?