testpaths + pyargs regression in 4.0.0

[ipmb]

I was using the following config to test specific modules, but it looks like they are now assumed to be relative paths instead of pyargs:

addopts = --pyargs
testpaths =
    module_one
    module_two

The exact error is:

ERROR: file or package not found: /path/to/cwd/module_one (missing __init__.py?)

Previously, module_one would be found on the PYTHONPATH instead of looking in the current working directory.

git bisect reports:

3137c89cf1232d5c68802cdc187354b8d9909f31 is the first bad commit
commit 3137c89cf1232d5c68802cdc187354b8d9909f31
Author: Daniel Hahler <git@thequod.de>
Date:   Thu Nov 8 00:54:51 2018 +0100

    Fix/improve handling of chdir with no-args and testpaths

    Fixes https://github.com/pytest-dev/pytest/issues/4332.

:040000 040000 b838be74b2381e8099fdcfe8ee11b65072583236 e10eb4bba2c6061029ac829ad9cd4c3a32ca273c M	src
:040000 040000 4710f7fa341f181287e744bbf5c4175a4bc57835 f1feab1f0c834e3a89ca914a5df7b437dce731b7 M	testing
bisect run success

[RonnyPfannschmidt]

interesting find and very unexpected combination

[ipmb]

Is there a more standard way to accomplish the same thing? I'm doing something like this in conftest.py to dynamically adjust the testpaths based on the environment:

def pytest_configure(config):
    """Adds custom apps to testpaths"""
    # ...
    if condition_x:
        config.args.remove('module_two')
    if condition_y:
        config.args.append('module_three')

[RonnyPfannschmidt]

@ipmb its not quite clear what your actual use-case is - without a better understanding of the actual goal i cant even remotely approach giving a sound/sane suggestion

[ipmb]

When I run pytest I want it to test different modules in my project based on the current environment (defined via environment variables and/or a config file). I've defined a default set of modules in setup.cfg like so:

[tool:pytest]
addopts = --pyargs
# Additional paths are dynamically appended in conftest.py
testpaths =
    module_one
    module_two

At runtime, I use the pytest_configure function to inspect the current environment and adjust the testpaths accordingly as shown in my previous comment.

[RonnyPfannschmidt]

@ipmb and why are those picked based on env vars? thats a key point for suggesting a solution

[ipmb]

Long story, but the project with the pytest configuration serves as an umbrella project for many unique deployments/environments used by customers. Different customers have different configurations and may be bringing in their own modules which we want to test as well.

The project architecture predates any pytest usage, I am trying to bring in pytest with minimal changes in the existing projects and configurations

[RonnyPfannschmidt]

@ipmb i see - then off hand i have no good solution either , i might get an idea with a good night of sleep tho

[blueyed]

The use case is valid, and #4411 should fix it.

[RonnyPfannschmidt]

@blueyed great job 👍