allow to dynamically modify all ini-values from plugins

[pytestbot]

Originally reported by: Alexander Schepanovski (BitBucket: suor, GitHub: suor)

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Here is my conftest.py

#!python
def pytest_addoption(parser):
    parser.addoption('--bench',
           action="store_true", dest="bench", default=False,
           help=("Enable benchmark mode"))

def pytest_configure(config):
    if config.getvalue("bench"):
        config.addinivalue_line("python_files", "bench_*.py") # Problem here

and it raises AssertError.

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• Bitbucket: https://bitbucket.org/pytest-dev/pytest/issue/204

[pytestbot]

Original comment by Alexander Schepanovski (BitBucket: suor, GitHub: suor):

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Same with python_functions

[pytestbot]

Original comment by holger krekel (BitBucket: hpk42, GitHub: hpk42):

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The config.addinivalue_line is meant to add to linelists, not args.
For example, "markers" is a linelist, whereas python_files/functions
is of type "args", thus returns a tuple. Modifying should be generalized -
in the context of dynamically setting any ini-file value, though.

In the meanwhile here is a workaround. If you use this conftest.py::

# content of conftest.py

def pytest_addoption(parser):
    parser.addoption('--bench',
           action="store_true", dest="bench", default=False,
           help=("Enable benchmark mode"))

def addini_arg(config, name, arg):
    args = config.getini(name)
    args = tuple(args) + (arg,)
    # hack it back to the config ini-value cache
    config._inicache[name] = args
    assert config.getini(name) == args

def pytest_configure(config):
    if config.getvalue("bench"):
        addini_arg(config, "python_files", "bench_*.py")
        addini_arg(config, "python_functions", "bench_")

and add a test like this::

# content of bench_something.py

def bench_1():
    pass

you can run it as expected::

$ py.test --bench
=========================== test session starts ============================
platform linux2 -- Python 2.7.3 -- pytest-2.3.1
plugins: xdist, bugzilla, cache, cli, pep8, timeout, oejskit, cov
collected 1 items
bench_something.py .

========================= 1 passed in 0.02 seconds ========================

[nicoddemus]

This works for me on current master:

def pytest_addoption(parser):
    parser.addoption('--bench',
           action="store_true", dest="bench", default=False,
           help=("Enable benchmark mode"))

def pytest_configure(config):
    if config.getvalue("bench"):
        config.addinivalue_line("python_files", "bench_*.py")
        config.addinivalue_line("python_functions", "bench_")

============================= test session starts =============================
platform win32 -- Python 3.4.3, pytest-2.8.0.dev4, py-1.4.30, pluggy-0.3.0
rootdir: X:\temp\issues-session, inifile:
collected 1 items

bench_something.py .

========================== 1 passed in 0.01 seconds ===========================

So I'm closing this for now. 😄

cc @Suor, @hpk42