Change -p so it is possible to early load setuptools plugins

[nicoddemus]

Related to pytest-dev/pluggy#189

Fixes #4718

[RonnyPfannschmidt]

while this works, this breaks refactoring where a plugin is moved but the plugin name doesn't change

we definitively should look if a plugin name is a entrypoint instead

[nicoddemus]

while this works, this breaks refactoring where a plugin is moved but the plugin name doesn't change

Hmm that did not occur to me, could you provide an example?

we definitively should look if a plugin name is a entrypoint instead

Not sure I get this, can you elaborate?

[RonnyPfannschmidt]

@nicoddemus

while this works, this breaks refactoring where a plugin is moved but the plugin name doesn't change

Hmm that did not occur to me, could you provide an example?

if someone moves xdist = xdist.pytest_plugin to say xdist = xdist.core then a user would have to change invocations to keep it working, from my pov that limitation is something we should try hard to avoid

we definitively should look if a plugin name is a entrypoint instead

Not sure I get this, can you elaborate?

when passing -p pytest_cov we should look if there is a setuptools entrypoint with that name as well

[nicoddemus]

Oh got it! Sure sure, that makes much more sense. 👍 I was not 100% happy with the solution either because it is not explicitly obvious what the user should be passing.

I will get to it.

[codecov]

Codecov Report

Merging #4727 into features will increase coverage by 0.02%.
The diff coverage is 96.77%.

@@             Coverage Diff              @@
##           features    #4727      +/-   ##
============================================
+ Coverage     95.61%   95.64%   +0.02%     
============================================
  Files           113      113              
  Lines         25163    25216      +53     
  Branches       2498     2504       +6     
============================================
+ Hits          24060    24117      +57     
+ Misses          776      775       -1     
+ Partials        327      324       -3

Flag	Coverage Δ
#docs	29.53% <8.06%> (+0.03%)	⬆️
#doctesting	29.53% <8.06%> (+0.03%)	⬆️
#linting	29.53% <8.06%> (+0.03%)	⬆️
#linux	95.48% <96.77%> (+0.02%)	⬆️
#nobyte	92.21% <96.77%> (+0.01%)	⬆️
#numpy	93% <96.77%> (+0.02%)	⬆️
#pexpect	41.88% <8.06%> (-0.08%)	⬇️
#pluggymaster	93.56% <96.77%> (+0.08%)	⬆️
#py27	93.67% <96.77%> (+0.02%)	⬆️
#py34	91.6% <96.77%> (+0.01%)	⬆️
#py35	91.63% <96.77%> (+0.01%)	⬆️
#py36	91.65% <96.77%> (+0.01%)	⬆️
#py37	93.82% <96.77%> (+0.03%)	⬆️
#trial	93% <96.77%> (+0.02%)	⬆️
#windows	93.57% <96.77%> (ø)	⬆️
#xdist	93.7% <96.77%> (ø)	⬆️

Impacted Files	Coverage Δ
src/_pytest/helpconfig.py	97.29% <ø> (ø)	⬆️
src/_pytest/config/__init__.py	93.82% <100%> (+0.02%)	⬆️
testing/acceptance_test.py	98.01% <100%> (+0.15%)	⬆️
testing/test_config.py	99.46% <87.5%> (-0.17%)	⬇️
src/_pytest/terminal.py	91.74% <0%> (+0.82%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c9e6943...a020727. Read the comment docs.

[nicoddemus]

😷

[RonnyPfannschmidt]

this allows 2 extra kex features a s followup

a) putting pytests own plugins into entrypoints (using a own entrypoint limited to pytest core)
b) inventing a naming mechanism for plugins that do not autoload, but should have a short name to autoload

it may be necessary to go a step further on pluggy and externalizing the plugin loader concept for a better behavioral envelope

[nicoddemus]

Applied all the changes I wanted.

This works locally when using together with pytest-dev/pluggy#189, so we will have to wait for that to get merged and released before we can merge this one. 👍

[nickwilliams-eventbrite]

Excited to see this land! Thanks for all of this!

[nicoddemus]

Rebased now that pluggy 0.9 is out. 👍