document and/or change display of parametrization values in IDs

[pytestbot]

Originally reported by: Anonymous

---

There are some values of a parametrized argument that py.test seems unable to print to terminal during reports (or to file with --reportlog) - so far I have encountered it with UTF-8 content and the value None.

In the test report, it prints an internal identifier ('param6' for example).

Example script to reproduce:

#!python
# -*- coding: utf-8 -*-
import pytest

def pytest_generate_tests(metafunc):
    metavalues = ['test', u'Стоял он, дум великих полн', '<h1>HTML string</h1>', None, False,True,'']
    metafunc.parametrize('metastuff', metavalues)

def test_meta(metastuff):
    print '\n%s'%(metastuff)

Example output:

#!bash

platform linux2 -- Python 2.7.2 -- pytest-2.3.4 -- /home/james/qa_activepython27/bin/python
collected 7 items 

test_pytest_metanames.py:8: test_meta[test] 
test
PASSED
test_pytest_metanames.py:8: test_meta[metastuff1] 
Стоял он, дум великих полн
PASSED
test_pytest_metanames.py:8: test_meta[<h1>HTML string</h1>] 
<h1>HTML string</h1>
PASSED
test_pytest_metanames.py:8: test_meta[metastuff3] 
None
PASSED
test_pytest_metanames.py:8: test_meta[False] 
False
PASSED
test_pytest_metanames.py:8: test_meta[True] 
True
PASSED
test_pytest_metanames.py:8: test_meta[] 

PASSED

As you can see from the sample output, there's no issue with these values being printed to terminal in the general case.

---

• Bitbucket: https://bitbucket.org/pytest-dev/pytest/issue/249

[pfctdayelise]

Support for custom IDs has been improved in the last year or so. And these all seem OK now.

@pytest.mark.parametrize('a', ['test', u'Стоял он, дум великих полн', '<h1>HTML string</h1>', None, False,True,''])
def test_params(a):
    print(a)

Output:

testing/test_foo.py::test_params[test] test
PASSED
testing/test_foo.py::test_params[Стоял он, дум великих полн] Стоял он, дум великих полн
PASSED
testing/test_foo.py::test_params[<h1>HTML string</h1>] <h1>HTML string</h1>
PASSED
testing/test_foo.py::test_params[None] None
PASSED
testing/test_foo.py::test_params[False] False
PASSED
testing/test_foo.py::test_params[True] True
PASSED
testing/test_foo.py::test_params[] 
PASSED