Use docstrings to list tests in py.test

Question

Here is a simple test file:

# test_single.py
def test_addition():
    "Two plus two is still four"
    assert 2 + 2 == 4

def test_addition2():
    "One plus one is still two"
    assert 1 + 1 == 2

The default output in py.test is like

$ py.test test_single.py -v
[...]
test_single.py::test_addition PASSED
test_single.py::test_addition2 PASSED

I would like to have

Two plus two is still four PASSED
One plus one is still two PASSED

i.e. use the docstrings as descriptions for the tests.

I tried to use a customization in a conftest.py file:

import pytest

@pytest.mark.tryfirst
def pytest_runtest_makereport(item, call, __multicall__):
    # execute all other hooks to obtain the report object
    rep = __multicall__.execute()
    if rep.when == "call":
        extra = item._obj.__doc__.strip()
        rep.nodeid =  extra
    return rep

that is close, but it repeats the filename on every line:

$ py.test test_single.py
======================================================================================== test session starts =========================================================================================
platform darwin -- Python 2.7.7 -- py-1.4.26 -- pytest-2.6.4
plugins: greendots, osxnotify, pycharm
collected 2 items

test_single.py
And two plus two is still four .
test_single.py
And one plus one is still two .

====================================================================================== 2 passed in 0.11 seconds ======================================================================================

How can I avoid the lines with test_single.py in the output, or maybe print it only once?

Looking into the source of py.test and some of its plugins did not help.

I am aware of the pytest-spec plugin, but that uses the function's name as a description. I don't want to write def test_two_plus_two_is_four().

Answer 1

I was missing rspec in ruby for python. So, based on the plugin pytest-testdox., I have written similar one which takes doc strings as report message. You can check it out pytest-pspec.

Answer 2

@Matthias Berth, you can try to use pytest_itemcollected

def pytest_itemcollected(item):
""" we just collected a test item. """
    item.setNodeid('' if item._obj.__doc__ is None else item._obj.__doc__.strip() )

and modify pydir/Lib/site-packages/pytest-2.9.1-py2.7.egg/_pytest/unittest.py add the following function to the TestCaseFunction class

def setNodeid(self, value):
    self._nodeid = value

and the result will be :

platform win32 -- Python 2.7.10, pytest-2.9.1, py-1.4.31, pluggy-0.3.1 -- D:\Python27\python.exe
cachedir: .cache
rootdir: E:\workspace\satp2\atest\testcase\Search\grp_sp, inifile:
plugins: html-1.8.0, pep8-1.0.6
collecting 0 itemsNone
collected 2 items
Two plus two is still four <- sut_amap3.py PASSED
One plus one is still two <- sut_amap3.py PASSED

by the way when you are using pytest-html you can use the pytest_runtest_makereport function you make and it will generate the report with the name you customized. hope this helps.

Answer 3

To expand on my comment to @michael-wan's answer: to achive something similar to specplugin put into conftest.py:

def pytest_itemcollected(item):
    par = item.parent.obj
    node = item.obj
    pref = par.__doc__.strip() if par.__doc__ else par.__class__.__name__
    suf = node.__doc__.strip() if node.__doc__ else node.__name__
    if pref or suf:
        item._nodeid = ' '.join((pref, suf))

and the pytest output of

class TestSomething:
"""Something"""

def test_ok(self):
    """should be ok"""
    pass

will look like

If you omit docstrings class/func names will be used.

Answer 4

For a plugin that (I think) does what you want out of the box, check out pytest-testdox.

It provides a friendly formatted list of each test function name, with test_ stripped, and underscores replaced with spaces, so that the test names are readible. It also breaks up the sections by test file.

This is what the output looks like: