mock.patch with py2 and p3

[Hellowlol]

Thanks for submitting an issue!

Here's a quick checklist in what to include:

• Include a detailed description of the bug or suggestion
  Im wondering if there is a bug in pytest. I get a exception when i try to rename input or raw input depending on the python version.
• pip list of the virtual environment you are using
  py3

aiohttp (0.21.5)
apipkg (1.4)
chardet (2.3.0)
colorama (0.3.7)
coverage (4.1)
curio (0.1)
enum-compat (0.0.2)
execnet (1.4.1)
mock (2.0.0)
pbr (1.10.0)
pip (8.1.2)
py (1.4.31)
pytest (2.9.2)
pytest-cov (2.2.1)
pytest-mock (1.1)
pytest-xdist (1.14)
requests (2.9.1)
setuptools (18.2)
six (1.10.0)
tqdm (3.8.0)
workerpool (0.9.4)

py2 list

addict (0.4.0)
addicted (0.0.5)
alabaster (0.7.7)
apipkg (1.4)
arrow (0.7.0)
Babel (2.2.0)
backports-abc (0.4)
backports.ssl-match-hostname (3.5.0.1)
beautifulsoup4 (4.4.1)
blitzdb (0.2.12)
bottle (0.12.9)
CacheControl (0.11.6)
certifi (2016.2.28)
cffi (1.6.0)
Cheetah (2.4.4)
colorama (0.3.7)
colorconsole (0.7.2)
CProfileV (1.0.7)
cryptography (1.3.2)
decorator (4.0.6)
doc2md (0.1.0)
docopt (0.6.2)
docutils (0.12)
dpath (1.4.0)
ecdsa (0.13)
enum-compat (0.0.2)
enum34 (1.1.6)
execnet (1.4.1)
FormEncode (1.3.0)
funcsigs (1.0.2)
functools32 (3.2.3.post2)
future (0.15.2)
futures (3.0.3)
Glances (2.5.1)
html5lib (0.9999999)
idna (2.1)
imdbpie (4.0.2)
IMDbPY (5.0)
ipaddress (1.0.16)
ipykernel (4.3.1)
ipython (4.1.2)
ipython-genutils (0.1.0)
ipywidgets (4.1.1)
iso8601 (0.1.11)
Jinja2 (2.8)
jsonpath-rw (1.4.0)
jsonrpclib-pelix (0.2.6)
jsonschema (2.5.1)
jupyter (1.0.0)
jupyter-client (4.2.1)
jupyter-console (4.1.1)
jupyter-core (4.1.0)
lifter (0.2.1)
line-profiler (1.0)
lockfile (0.12.2)
lxml (3.5.0)
m3u8 (0.2.8)
Markdown (2.6.5)
MarkupSafe (0.23)
mistune (0.7.2)
mock (2.0.0)
nbconvert (4.1.0)
nbformat (4.0.1)
netdisco (0.6.4)
netifaces (0.10.4)
noattr (0.0.6)
notebook (4.1.0)
oauthlib (1.0.3)
paramiko (2.0.0)
path.py (8.1.2)
pbr (1.8.1)
pickleshare (0.6)
Pillow (3.1.0)
pip (8.1.2)
pipreqs (0.4.2)
PlexAPI (2.0.0a-..................................-.version.of.this.api)
ply (3.8)
pockets (0.3)
profilehooks (1.8.1)
psutil (3.4.1)
py (1.4.31)
pyasn1 (0.1.9)
pycparser (2.14)
pycrypto (2.6.1)
Pygments (2.1)
pyment (0.3.2.dev0)
Pympler (0.4.2)
pyOpenSSL (0.15.1)
pypiwin32 (219)
pyreadline (2.1)
pytest (2.9.2)
pytest-mock (1.1)
pytest-xdist (1.14)
python-dateutil (2.4.2)
python-qbittorrent (0.1.5)
pytz (2015.7)
PyYAML (3.11)
pyzmq (15.2.0)
qtconsole (4.2.0)
records (0.4.0)
requests (2.9.1)
requests-futures (0.9.5)
requirements-txt (0.0.0)
selenium (2.53.0)
setuptools (22.0.0)
simplegeneric (0.8.1)
simplejson (3.8.1)
singledispatch (3.4.0.3)
six (1.10.0)
snowballstemmer (1.2.1)
Sphinx (1.3.5)
sphinx-rtd-theme (0.1.9)
SQLAlchemy (1.0.11)
sqlalchemy-migrate (0.10.0)
SQLObject (2.1.2)
sqlparse (0.1.18)
tablib (0.11.1)
tellcore-py (1.1.2)
tellive-py (0.5.2)
Tempita (0.5.2)
tornado (4.3)
tqdm (4.4.0)
traitlets (4.1.0)
tvdb-api (1.10)
ujson (1.35)
wheel (0.29.0)
workerpool (0.9.4)
xmltodict (0.10.1)
yappi (0.94)
yarg (0.1.9)
youtube-dl (2016.3.6)
zeroconf (0.17.5)

• [x ] Minimal example if possible

Test script to recreate the error

from __future__ import print_function

import mock
import sys

if sys.version_info >= (3, 0):
    ips = 'builtins.input'
    #input = input
else:
    ips = '__builtin__.raw_input'
    input = raw_input


def something():
    print("test")
    x = input('\nEnter stuff\n')
    print("s")
    return x


def test_something():
    with mock.patch(ips, return_value='::'):
        assert something() == '::'

py2 with raw_input renamed to input:

============================= test session starts =============================
platform win32 -- Python 2.7.10, pytest-2.9.2, py-1.4.31, pluggy-0.3.1
rootdir: C:\Users\admin\Desktop, inifile: 
plugins: mock-1.1, xdist-1.14
collected 0 items / 1 errors

=================================== ERRORS ====================================
_________________________ ERROR collecting tt_zomg.py _________________________
tt_zomg.py:26: in <module>
    test_something()
tt_zomg.py:22: in test_something
    f = something()
tt_zomg.py:15: in something
    x = input('\nEnter stuff\n')
c:\python27\lib\site-packages\_pytest\capture.py:433: in read
    raise IOError("reading from stdin while output is captured")
E   IOError: reading from stdin while output is captured
------------------------------- Captured stdout -------------------------------
test

Enter stuff
=========================== 1 error in 0.02 seconds ===========================

py3 with input

============================= test session starts =============================
platform win32 -- Python 3.5.1, pytest-2.9.2, py-1.4.31, pluggy-0.3.1
rootdir: C:\Users\admin\Desktop, inifile: 
plugins: cov-2.2.1, mock-1.1, xdist-1.14
collected 1 items

test_zomg.py .

========================== 1 passed in 0.03 seconds ===========================

[nicoddemus]

Thanks for reporting.

I assume if you pass -s (--capture=no) then the test works, is that right? Currently there's no way to disable capture for a test (there's been some discussion in #167 though).

Either way I think mocking builtins like open and input are a bad idea in general, as third-party libraries (like pytest) depend on them to work.

[Hellowlol]

I wouldnt say it works :P I mean i dont get any errors but i have to manually write in the cli inputs so its kinda useless. I have simply disabled he cli tests for python3 as a work around. Ill find another way to solve this

I only rename do i can support both python 2 and 3 in my script.

Thanks for your work on py test. Its awesome

[nicoddemus]

I wouldnt say it works :P I mean i dont get any errors but i have to manually write in the cli inputs so its kinda useless.

I see.

If you want a workaround: in situations where I want to mock a builtin and that's a problem for some reason, I usually write a thin wrapper and use that in my code:

def obtain_input(text):
    return input(text)

def delete_file():    
    response = obtain_input('continue?')
    ...

This way you can easily mock the thin wrapper instead on the tests themselves:

@pytest.yield_fixture
def fake_input():
    with mock.patch('module.obtain_input') as m:    
        yield m

def test_delete_file(fake_input):
    fake_input.return_value = 'y'
    module.delete_file()
    assert module.file_exists()

Just an idea. 😁

[Hellowlol]

Thanks for the suggestion. I ended up with replacing the renamed input/raw_input with

def compat_input(s=''):
    try:
        return raw_input(s)
    except NameError:
        return input(s)

Ill close this because of the issue you opened.