Using removed pytest warning function for error reporting

[loksonarius]

So while playing around with molecule, I tried running my first Testinfra specs. All good, but things would fail before even running my test. Sample output:

    ============================= test session starts ==============================
    platform darwin -- Python 3.6.5, pytest-4.1.1, py-1.7.0, pluggy-0.8.1
    rootdir: /Users/myusernamehere/Projects/personal/consul-appliance/molecule/default, inifile:
    plugins: testinfra-1.16.0
collected 2 items
    INTERNALERROR> Traceback (most recent call last):
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/_pytest/main.py", line 203, in wrap_session
    INTERNALERROR>     session.exitstatus = doit(config, session) or 0
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/_pytest/main.py", line 242, in _main
    INTERNALERROR>     config.hook.pytest_collection(session=session)
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/hooks.py", line 284, in __call__
    INTERNALERROR>     return self._hookexec(self, self.get_hookimpls(), kwargs)
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/manager.py", line 68, in _hookexec
    INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/manager.py", line 62, in <lambda>
    INTERNALERROR>     firstresult=hook.spec.opts.get("firstresult") if hook.spec else False,
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/callers.py", line 208, in _multicall
    INTERNALERROR>     return outcome.get_result()
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/callers.py", line 80, in get_result
    INTERNALERROR>     raise ex[1].with_traceback(ex[2])
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/callers.py", line 187, in _multicall
    INTERNALERROR>     res = hook_impl.function(*args)
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/_pytest/main.py", line 252, in pytest_collection
    INTERNALERROR>     return session.perform_collect()
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/_pytest/main.py", line 471, in perform_collect
    INTERNALERROR>     hook.pytest_collection_finish(session=self)
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/hooks.py", line 284, in __call__
    INTERNALERROR>     return self._hookexec(self, self.get_hookimpls(), kwargs)
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/manager.py", line 68, in _hookexec
    INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/manager.py", line 62, in <lambda>
    INTERNALERROR>     firstresult=hook.spec.opts.get("firstresult") if hook.spec else False,
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/callers.py", line 208, in _multicall
    INTERNALERROR>     return outcome.get_result()
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/callers.py", line 80, in get_result
    INTERNALERROR>     raise ex[1].with_traceback(ex[2])
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/pluggy/callers.py", line 187, in _multicall
    INTERNALERROR>     res = hook_impl.function(*args)
    INTERNALERROR>   File "/Users/myusernamehere/Projects/personal/consul-appliance/venv/lib/python3.6/site-packages/testinfra/plugin.py", line 183, in pytest_collection_finish
    INTERNALERROR>     session.config.warn('C1', msg)
    INTERNALERROR> AttributeError: 'Config' object has no attribute 'warn'

    ========================= no tests ran in 0.66 seconds =========================

I dug into the source code and found that the pytest hook function pytest_collection_finish (line 160 of plugin.py in the version of Testinfra I'm using), was failing to call session.config.warn.

From this point, I've come to realize I can avoid this call entirely by using the non-deprecated syntax of host.XXX instead of passing XXX as a parameter (in my case, XXX was the User module). This means my tests are now able to run cause I avoid that conditional branch of the if tree entirely.

From my digging before realizing this problem, I started looking through the pytest_hookspec, which lead me to this section of the pytest source code, where I noticed an oddly relevant commit message that was linked to this relevant discussion. Based off that discussion, it seems like there was a plan to deprecate and fully remove the .warn function from the Config object. I couldn't understand what changes consumers needed to make as I'm a bit of a scrub when it comes to Python 😄 , but it looks like version 4.0.X of pytest will require calls to the .warn function to be replaced with some new usage of a warning system. I'd offer a code change, but I honestly am very new to Python, let alone what looks to be advanced Python programing.

I don't have any pressing need for a fix on this, but wanted to open this issue in case a hard reason for adding pytest 4.0 support was needed.

[philpep]

Hi, thanks for reporting and digging into this issue. A fix is coming and will be released asap !

[philpep]

Fixed in 1.19.0